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1
Brito, Renan Guedes de. "Avaliação da atividade antinociceptiva e anti-inflamatória do citronelol em roedores". Universidade Federal de Sergipe, 2013. https://ri.ufs.br/handle/riufs/3854.
Testo completoAbstract (sommario):
Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorThe Citronellol (CT) is an alcoholic monoterpene present in the essential oil of some medicinal plants such as Cymbopogon citratus. Some pharmacological effects such as the antispasmodic and anticonvulsant activities have been described, however it s possible antinociceptive and anti-inflammatory effect is unknown. Thus, the objective of this study was to evaluate the possible antinociceptive and anti-inflammatory action of CT in rodents. Therefore, 362 male Swiss mice (25-35 g) with 2 to 3 months were used. The animals were divided into groups and were treated with CT (25, 50 and 100 mg/kg, i.p.), vehicle (saline solution 0.9% + Tween 80 0.2%, i.p.) or standard drug (i.p.). To evaluate the antinociceptive activity, the animals were submitted to the test of abdomnal constrictions induced by acetic acid (0.85%), the formalin test (1%) and hot plate test. In order to evaluate the effect of CT on orofacial nociception, it was conducted the orofacial test induced by formalin (2%), capsaicin and glutamate. Motor coordination was assessed using the motor coordination test (rota rod) and the spontaneous movement test. The anti-inflammatory activity was evaluated based on the model of carrageenan-induced pleurisy, making up the total leucocyte count. It was also quantified, by using ELISA, TNF-α and nitric oxide generation by macrophages. To determine the central action, the animals were treated with CT, in three doses, or vehicle and, after ninety minutes, were anesthetized, perfused, the brains removed and cut in a cryostat. The brain sections were subjected to immunofluorescence protocol for Fos protein. Results are expressed as mean ± SEM Differences between groups were analyzed by using one way ANOVA test, and followed by Tukey test. Values of p < 0.05 were considered statistically significant. Intraperitoneal administration of CT produced a significant decrease (p < 0.001) of the abdominal constrictions induced by acetic acid. In nociception induced by formalin, the pretreatment with CT caused a significant antinociceptive effect (p <0.01) in both phases of the test. In the hot plate test, the reaction time increased significantly at all doses of CT (p < 0.05 or p < 0.001), while its effect was antagonized by naloxone. In the three orofacial nociception tests, the CT produced a significant decrease (p <0.001) in the face-rubbing time of the orofacial region. No changes were observed in the motor coordination and in the spontaneous movement test. In the evaluation of anti-inflammatory activity, treatment with CT gave rise to a significant decrease (p < 0.01) in total number of leukocytes, decreasing (p < 0.05) the levels of TNF-α and nitric oxide in macrophages (p < 0.05). By immunofluorescence, it was found that CT is able to activate signicantly (p < 0.05) neurons of the olfactory bulb, the piriform cortex, the restrosplenial cortex and the periaqueductal gray. So, it can be concluded that CT has antinociceptive and anti-inflammatory activity and its action is mediated by central and peripheral mechanisms.
O Citronelol (CT) é um monoterpeno alcóolico presente no óleo essencial de algumas plantas medicinais, como o Cymbopogon citratus. Alguns efeitos farmacológicos tais como anti-espasmódico e atividade anticonvulsivante já foram descritos, sendo desconhecido seu possível efeito antinociceptivo e anti-inflamatório. Desta forma, o objetivo do presente estudo foi avaliar a possível ação antinociceptiva e anti-inflamatória do CT em roedores. Para tanto, foram utilizados 362 camundongos Swiss machos (25 a 35 g) com 2 a 3 meses. Os animais foram divididos em grupos e foram tratados com CT (25, 50 e 100 mg/kg; i.p.), veículo (solução salina 0,9% + tween 80 0,2%; i.p.) ou droga padrão (i.p.). Para avaliação da atividade antinociceptiva, os animais foram submetidos ao teste de contorções abdominais induzidas por ácido acético (0,85%), ao teste da formalina (1%) e ao teste da placa quente. Com o intuito de avaliar a ação do CT na nocicepção orofacial, foram realizados os testes de dor orofacial induzida por formalina (2%), capsaicina e glutamato. A coordenação motora dos animais foi avaliada através do teste da coordenação motora (rota rod) e do teste da movimentação espontânea. A atividade anti-inflamatória foi avaliada a partir do modelo de pleurisia induzido por carragenina, realizando-se a contagem de leucócitos totais. Foi quantificado, ainda, através do ensaio imunoenzimático ELISA, o TNF-α e a geração de óxido nítrico por macrófagos. Para determinar a ação central, os animais foram tratados com CT, nas três doses, ou veículo e, noventa minutos após, foram anestesiados, perfundidos, os cérebros extraídos e cortados em criostato. As secções cerebrais foram submetidas ao protocolo de imunofluorescência para proteína Fos. Os resultados foram expressos como média ± erro padrão da média. As diferenças entre os grupos foram analisadas por meio do teste de variância ANOVA, uma via, seguido pelo teste de Tukey. Valores de p < 0,05 foram considerados estatisticamente significantes. A administração intraperitoneal de CT produziu uma redução significativa (p < 0,001) das contorções abdominais. Na nocicepção induzida por formalina, o pré-tratamento com CT causou um efeito antinociceptivo significativo (p <0,01) em ambas as fases do teste. No teste da placa quente, o tempo de reação aumentou significativamente em todas as doses de CT (p < 0,05 ou p < 0,001), tendo seu efeito antagonizado pela naloxona. Nos três testes de nocicepção orofacial, o CT produziu uma redução significativa (p < 0,001) no tempo de fricção da região orofacial. Não foram observadas alterações no teste da coordenação motora e no teste da movimentação espontânea. Na avaliação da atividade anti-inflamatória, o tratamento com CT causou uma diminuição significativa (p < 0,01) no número total de leucócitos, diminuindo os níveis de TNF-α (p < 0,05) e de óxido nítrico em macrófagos (p < 0,05). Através da imunofluorescência, observou-se que o CT é capaz de ativar signicativamente (p < 0,05) neurônios do bulbo olfatório, do córtex piriforme, do córtex retroesplenial e da substância cinzenta periaquedutal. Conclui-se, assim, que o CT apresenta ação antinociceptiva e anti-inflamatória, tendo sua ação mediada por mecanismos centrais e periféricos.
2
Filho, Helder Veras Ribeiro. "Cardiorespiratory effects of β-citronellol: involvement of vagal afferent fibers and direct actions on cardiac and smooth muscles". Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=14470.
Testo completoAbstract (sommario):
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgicoβ-Citronelol à um monoterpeno encontrado no Ãleo essencial de diversas plantas aromÃticas utilizadas na medicina popular para tratar hipertensÃo, como a Cymbopogon citratus. O β-citronelol possui propriedades hipotensoras e vasorrelaxantes, porÃm seu mecanismo ainda nÃo està claro. Portanto, o presente estudo foi realizado para abordar essa questÃo em ratos normotensos. Para os experimentos in vivo, ratos Wistar macho foram submetidos a cateterizaÃÃo da artÃria e veia femoral esquerda para registro da pressÃo arterial mÃdia e para administraÃÃo de substÃncias, respectivamente. Eletrodos permitiram o registro da frequÃncia cardÃaca e certos grupos de animais foram traqueostomizados para anÃlise da frequÃncia respiratÃria. Para os experimentos in vitro, os Ãtrios direito e esquerdo, e anÃis de artÃria mesentÃrica foram suspensos em cubas para ÃrgÃos isolados sob condiÃÃes fisiolÃgicas. Em ratos anestesiados com uretana, injeÃÃes intravenosas (i.v.) de β-citronelol (5 e 10 mg/kg) causaram hipotensÃo, bradicardia e apneia em duas fases (fase 1 e fase 2), assim como em animais acordados (5, 10 e 20 mg/kg). A fase 1 dessa trÃade (1 â 2 s de latÃncia), foi abolida pela vagotomia bilateral (BV), pelo tratamento perineural com capsaicina (TP) ou pelo prÃ-tratamento com metilatropina (MA, i.v.), assim como pela injeÃÃo do β-citronelol dentro do ventrÃculo esquerdo, mas manteve-se inalterada pelo prÃ-tratamento i.v. com capsazepina, ondansetrona, suramina ou HC-030031. A fase 2 tardia de bradicardia foi tambÃm reduzida pela BV, TP ou MA, enquanto que a apneia de fase 2 foi abolida apenas pela suramina. Em preparaÃÃes atriais, o β-citronelol induziu efeito cronotrÃpico e inotrÃpico negativos, os quais nÃo parecem estar envolvidos com receptores muscarÃnicos ou adrenÃrgicos, ou alteraÃÃes no influxo de cÃlcio. Em anÃis de artÃria mesentÃrica, com e sem endotÃlio, o β-citronelol relaxou totalmente prÃ-contraÃÃes de fenilefrina com equiparÃvel potÃncia. Esses resultados revelam que a fase 1 de efeitos do β-citronelol origina-se atravÃs de um reflexo vago-vagal resultante da estimulaÃÃo de aferÃncias pulmonares vagais, que parecem nÃo envolver receptores TRPV1, TRPA1, 5-HT3 ou P2X. A fase 2 de hipotensÃo e bradicardia parece resultar de uma aÃÃo de vasodilataÃÃo direta e de um efeito cardÃaco depressor, respectivamente. AlÃm disso, receptores P2X parecem estar envolvidos na mediaÃÃo da resposta de fase 2 de apneia induzida por esse monoterpeno acÃclico.
β-Citronellol is a monoterpene found in the essential oil of various aromatic plants used in folk medicine to treat hypertension such as Cymbopogon citratus. β-Citronellol possesses hypotensive and vasorelaxant properties, but the mechanism of such effects remains unclear. Therefore, the present study was undertaken to address this issue in normotensive rats. For in vivo experiments, male Wistar rats were subjected to catheterization of the left femoral artery and vein for mean arterial pressure monitoring and drug injection, respectively. Electrodes allowed heart rate recordings and some groups of rats were tracheostomized for respiratory rate analysis. For in vitro experiments, right and left atria, and mesenteric artery rings were suspended in organ baths at physiological conditions. In urethane-anesthetized rats, intravenous (i.v.) injections of β-citronellol (5 and 10 mg/kg) caused biphasic (phase 1 and phase 2) hypotension, bradycardia and apnea responses. Biphasic responses was observed also following i.v. injection of β-citronellol (5, 10 and 20 mg/kg) in unanesthetized rats. Phase 1 of this triad (onset time of 1-2 s) was abolished by bilateral vagotomy (BV), perineural treatment with capsaicin (PNT) or pretreatment with methylatropine (MA, i.v.), but remained unaltered by i.v. pretreatment with capsazepine, ondansetron, suramin or HC-030031. Phase 1 responses was absent when β-citronellol was injected into the left ventricle. The delayed phase 2 of bradycardia was also partially reduced by BV, PNT or MA while the apnea component of this phase 2 was only abolished by suramin. In atrial preparations, β-citronellol induced chronotropic and inotropic negative responses, an effect that was related to neither muscarinic and adrenergic receptor activation nor to altered calcium influx. In both endothelium-intact and denuded mesenteric artery rings, β-citronellol fully relaxed phenylephrine-induced contractions in a concentration-dependent manner and with equal potency. These findings reveal that the effects evoked by β-citronellol induced vago-vagal reflex due to stimulation of vagal pulmonary afferents, an effect that seems not involving TRPV1, TRPA1, 5-HT3, or P2X receptors. Phase 2 hypotensive and bradycardiac responses to β-citronellol appears resulting from a direct vasodilatory effect upon vascular smooth muscle and cardiac depressor action, respectively. Furthermore, P2X receptors seem to be involved in the mediation of phase 2 apneic response to this acyclic monoterpene.
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Victoria, Francine Novack. "Novos compostos organosselênio bioativos: estudo da ação antimicrobiana frente à patógenos de importância em alimentos". Universidade Federal de Pelotas, 2010. http://repositorio.ufpel.edu.br/handle/ri/1321.
Testo completoAbstract (sommario):
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Previous issue date: 2010-02-26Java citronella (Cymbopogon nardus (L) Rendle) belongs to the genus Cymbopogon and the essential oil extracted from the plant is constituted mainly by the (+)-R-citronellal (3,7-dimethyl-6-octenal), formed by the secondary metabolism plants. Essential oils and plant extracts have a growing interest to industry and scientific research due to its antimicrobial activity, and as well as compounds organosselênios that are of great interest for scientific research because of its wide spectrum of biological activity. Thus, we performed a study of α-selenation of aldehydes and ketones, including the (+)-( R)-citronellal, as a major component of essential oil of citronella, using PEG/KF/Al2O3, as a recyclable medium. Derivatives of (+)- (R)-citronellal containing organoselenium were assessed for their potential antimicrobial, the antimicrobial activity was determined by the techniques of disk diffusion and minimum inhibitory concentration. The 2-phenylseleno citronellal and 2 phenylseleno citronellol provided yields of 71 and 73% respectively. The antimicrobial activity of 2- phenylseleno citronellal showed the best results, soon the addition of a organoselenium to (+)-R-citronellal increased the antimicrobial activity of (+)-R-citronellal against foodborne pathogenic bacteria Listeria monocytogenes, Staphylococcus aureus and Salmonella Typhimurium.
O capim citronela (Cymbopogon nardus(L) Rendle) pertence ao gênero Cymbopogon, o óleo essencial extraído da planta tem como principal constituinte o (+)-R-citronelal (3,7-dimetil-oct-6-enal), predominantemente formado pelo metabolismo secundário das plantas. Os óleos essenciais e os extratos das plantas possuem um interesse crescente para a indústria e para a pesquisa científica devido a sua atividade antimicrobiana, assim como os compostos organosselênios que são de grande interesse para a pesquisa científica devido ao seu grande espectro de atividade biológica. Desta forma, foi realizado um estudo da α-selenização de aldeídos e cetonas, incluindo o (+)-(R)-citronelal, principal componente do óleo essencial de citronela, utilizando PEG/KF/Al2O3, como meio reciclável. Os derivados do (+)-(R)-citronelal contendo organosselênio foram avaliados em relação aos seus potenciais antimicrobianos, determinados pelas técnicas de difusão do disco e concentração inibitória mínima. Os produtos 2-fenilselenocitronelal e 2-fenilselencitronelol apresentaram rendimentos de 71 e 73%, respectivamente. Nos ensaios de atividade antimicrobiana o produto 2-fenilselenocitronelal apresentou os melhores resultados, inclusive melhores que o (+)-R-citronelal. Logo, a adição de um grupamento de selênio ao composto (+)-R-citronelal aumentou sua atividade antimicrobiana contra Listeria monocytogenes, Staphylococcus aureus e Salmonella Typhimurium.
4
Oliveira, Heloisa Mara batista Fernandes de. "Avaliação das atividades antifúngica, antioxidante e citotóxica dos monoterpenos (r)-(+)-citronelal, (s)-(-)-citronelal, 7-hidroxicitronelal". Universidade Federal da Paraíba, 2016. http://tede.biblioteca.ufpb.br:8080/handle/tede/9078.
Testo completoAbstract (sommario):
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq
Serious infections caused by opportunistic fungal pathogens such as Candida genus, have been increasingly common in immunocompromised patients. The spread of drug-resistant fungi is one of the most serious threats to the successful treatment of fungal diseases, in addition, some drugs are very toxic, hindering adherence to therapy. In this context, the monoterpenes have stood out for having various pharmacological activities such as fungicide and bactericide. It also stands out the antioxidant activity of these compounds by being able to react and inactivate the different reactive species produced during a cellular oxidative stress. Based on this, the antifungal, cytotoxic and antioxidant effect of the monoterpenes (R)-(+)-citronellal (RC), (S)-(-)-citronellal (SC) and 7-hydroxycitronellal (7-OH) were studied. For the analysis of the antimicrobial potential of monoterpenes was used with the in silico analysis software Pass online. For the realization of antifungal studies used the microdilution test with different fungal strains of Candida for evaluation of minimum inhibitory concentration (MIC). In addition, it was determined the Minimum Fungicidal Concentration (MFC) for seeding on plates. In carrying out cytotoxicity studies and antioxidant was used human red blood cells obtained from the transfusion unit of the University Hospital Lauro Wanderley/UFPB. For the antioxidant studies used the techniques with phenylhydrazine and hydrogen peroxide. The study showed that the in silico monoterpenes RC, SC and 7-OH were more likely to be active in percentage, compared to fungal microorganisms. The antifungal activity of experiments revealed that the RC and SC monoterpenes promoted strong antifungal effect with MIC50 of 256 μg/mL for strains of Candida albicans and Candida tropicalis and fungicidal action for presenting CFM50 512 μg/mL. The monoterpene 7-OH showed strong antifungal effect for both strains of Candida albicans and for Candida tropicalis strains with MIC50 of 256 μg/mL and MIC50 512 μg/mL, respectively, and fungicidal action with CFM50 512 μg/mL and 1024 μg/mL. The monoterpenes RC, SC and 7-OH showed no oxidant opposite effect to human erythrocytes. Furthermore, the front monoterpenes had antioxidant effect against phenylhydrazine and hydrogen peroxide. RC analysis of cytotoxicity, SC and 7-OH front of haemolysis erythrocytes showed values below 25% for all blood types tested at a concentration of 256 μg/mL. Given these results, it was possible to infer that the stereoisomerism of RC and SC monoterpenes did not interfere in the tested activities. In conclusion, these results suggest that the RC, SC-OH and 7 show antifungal and antioxidant effect with low cytotoxic effect.
As infecções graves causadas por fungos patogênicos oportunistas, tais como do gênero Candida, têm sido cada vez mais comuns em pacientes imunocomprometidos. A disseminação de fungos resistentes aos medicamentos é uma das mais graves ameaças para o sucesso do tratamento das doenças fúngicas, além disso, algumas drogas são muito tóxicas, dificultando a adesão a terapêutica. Nesse contexto, os monoterpenos têm se destacado por apresentarem diversas atividades farmacológicas tais como: fungicida e bactericida, além da atividade antioxidante, por serem capazes de reagir e inativar as diferentes espécies reativas produzidas durante um estresse oxidativo celular. Com base nisto, foram estudados os efeitos antifúngico, citotóxico e antioxidante dos monoterpenos (R)-(+)-citronelal (RC), (S)-(-)-citronelal (SC) e 7-hidroxicitronelal (7-OH). Para a análise do potencial antimicrobiano dos monoterpenos foi utilizado a análise in silico com o software Pass online. Para a realização dos estudos antifúngicos utilizou-se o teste de microdiluição com diferentes cepas fúngicas do gênero Candida para avaliação da Concentração Inibitória Mínima (CIM). Além disso, determinou-se a Concentração Fungicida Mínima (CFM) por semeio em placas. Na realização dos estudos de atividade citotóxica e antioxidante utilizou-se hemácias humanas obtidas da unidade transfusional do Hospital Universitário Lauro Wanderley/UFPB. Para os estudos antioxidantes utilizou-se as técnicas com fenilhidrazina e peróxido de hidrogênio. O estudo in silico demonstrou que os monoterpenos RC, SC e 7-OH apresentaram uma maior probabilidade de serem ativos, expressa em porcentagem, frente aos microrganismos fúngicos. Os experimentos de atividade antifúngica revelaram que os monoterpenos RC e SC promoveram efeito antifúngico forte com CIM50 de 256 μg/mL para as cepas de Candida albicans e Candida tropicalis, bem como ação fungicida por apresentarem CFM50 512 μg/mL. O monoterpeno 7-OH apresentou forte efeito antifúngico tanto para as cepas de Candida albicans como para as cepas de Candida tropicalis, com CIM50 de 256 μg/mL e CIM50 512 μg/mL, respectivamente, bem como ação fungicida com CFM50 de 512 μg/mL e 1024 μg/mL. Os monoterpenos RC, SC e 7-OH não demonstraram efeito oxidante frente a eritrócitos humanos. Além disso, os monoterpenos apresentaram efeito antioxidante frente a fenilhidrazina e ao peróxido de hidrogênio. A análise da citotoxicidade de RC, SC e 7-OH frente a eritrócitos revelou valores de hemólise abaixo de 25% para todos os tipos sanguíneos testados, na concentração de 256 μg/mL. Diante desses resultados, foi possível inferir que a estereoisomeria dos monoterpenos RC e SC não interferiu nas atividades testadas. Em conclusão, estes resultados sugerem que o RC, SC e 7-OH apresentam efeito antifúngico e antioxidante, com baixo efeito citotóxico.
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Arias, Vecino Pablo. "Role of adsorption in catalysis : applications of NMR relaxometry". Thesis, University of Cambridge, 2015. https://www.repository.cam.ac.uk/handle/1810/248756.
Testo completoAbstract (sommario):
The work described in this thesis focuses on the effects that adsorption processes on catalytic surfaces pose in controlling key steps that can affect and control reaction pathways. To that, the development of Nuclear Magnetic Resonance (NMR) relaxometry methods and the comparison with traditional catalytic was performed with a series of C5 and C6 unsaturated hydrocarbons on two different alumina supports, γ- and θ-Al2O3. The developed techniques were applied in the study of liquid phase selective hydrogenation of citral on 5% Pt/SiO2. Infrared (IR) spectroscopy, volumetric adsorption isotherms, dynamic isotherms via a Tapered Element Oscillating Microbalance (TEOM), temperature programmed desorption (TPD) as well as 13C T1 NMR and 1H 2D T1-T2 relaxometry methods were employed. Energies of adsorption as a function of coverage were obtained via adsorption isotherms and the particular surface adsorbate interactions were described with IR spectroscopy. For example, 1-pentyne showed the strongest interaction with the alumina (94 kJ mol-1) while 1-pentene presented a weaker interaction (46 kJ mol-1) on θ-Al2O3. Desorption energies obtained from TPD ranged 85 – 130 kJ mol-1, irrespective of the adsorbate. Reactivity of the aluminas was captured with TPD, TEOM and NMR relaxometry. Interaction of adsorbates with hydrocarbon occurred predominantly on weak adsorption sites. 13C NMR T1 relaxometry provided in addition atom-specific adsorbate-adsorbent interaction strengths, showing the molecular geometry of adsorption, and applied in co adsorption measurements. The selective hydrogenation of citral as a model α,β-unsaturated aldehyde and the effect of different solvents on the activity and product distribution was studied at 298 and 373 K. A series of polar protic, polar aprotic and non polar solvents was investigated. Results showed higher initial reaction rates in non polar solvents but higher selectivities towards desired products on polar protic solvents. Solvent used also affected by product formation. The strong variations in reaction rates and selectivities reported were related with adsorbate catalyst interactions, as well as solvent reactant interactions. For example, adsorption isotherms showed that ethanol notably reduced the adsorption capacity of citral as compared with hexane, related with the rate differences observed. ATR-IR measurements indicated solvent citral interactions were solely present in polar protic solvents in line with higher yields of geraniol and nerol. Finally, 13C T1 NMR and 1H 2D T1-T2 correlation experiments determined that the geometry of adsorption of citral, influenced by solvent, affected product selectivity, and that product adsorption affected selectivity and deactivation.
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Paula, Camila Gurgel Dantas de. "Atividade antifúngica in vitro do óleo essencial de cymbopogon nardus L. Rendle (citronela) e do fitoconstituinte citronelal sobre cladosporium carrionii". Universidade Federal da Paraíba, 2015. http://tede.biblioteca.ufpb.br:8080/handle/tede/8637.
Testo completoAbstract (sommario):
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Dematiaceous, demaceous or dark fungi comprise a large, heterogeneous group of fungi that cause a variety of diseases, including feohifomycoses, cromoblastomycoses, mycetoma and allergies. Species of the genus Cladosporium are relevant in developing cromoblatomycoses, and stand out as plant contaminants. The toxicity of conventional antifungal and increased resistance to therapeutic regimens, driving the study of the antifungal activity of new alternatives, including natural sources. Given this context, the aim of this study was to evaluate the In vitro antifungal activity of seven essential oils (Laurus nobilis L., Mentha arvensis, Mentha X piperita L., Mentha spicata, Ocimum basilicum L., Cymbopogon nardus L. Rendle e Origanum vulgare) and the phytoconstituent citronellal on strains of dematiaceous fungi. In this study, the following methods were used: microbiological screening, determining the minimum inhibitory concentration (MIC) and Minimum Fungicidal Concentration (MFC), kinetics of microbial death, inhibition of conidial germination and evaluation of morphological changes. Among the essential oils tested, the C. nardus essential oil demonstrated potent antifungal activity, inhibiting the growth of 83,3% of strains used. The Cymbopogon Nardus L. Rendle (citronella grass) belongs to the family Poaceae, subfamily Panicoideae. The Cymbopogon genus consists of eighty-five species. C. nardus presents constitution of essential oil with two major compounds: the citronellal and geraniol. Citronellal is a monoterpene, predominantly formed by the secondary metabolism of plants. The essential oil of C. nardus had its MIC and MFC established at 64 mg / mL and the citronellal in 32 mg / mL. Both the essential oil of C. nardus as citronellal significantly inhibited the radial mycelial growth of the tested strains, the MIC concentrations, MICx2 and MICx4 after 12 days of exposure. In MIC50 concentrations (64 ug / ml- essential oil and 32μg / ml -citronellal) and MIC90 (128 ug / ml - 512μg essential oil and / ml - citronellal), were able to significantly inhibit the germination of fungal conidia from both strains tested. The determination of the effect of the essential oil of C. nardus and citronellal on the morphogenesis of C. carrionii strains showed that both were capable of inducing morphological changes, as development tortuous hyphae, fine and decreased conidiation in MIC concentrations, MICx2 and MICx4. Thus, it is concluded that the essential oil of C. nardus and its phytoconstituent citronellal showed pronounced antifungal activity against the strains of C. carrionii tested, what drives the study of its In vivo antifungal activity, as well as the search for pharmaceutical formulations to be used for the therapy of certain mycoses, especially those caused by dematiaceous fungi.
Fungos dematiáceos, demáceos ou escuros compõem um grupo grande e heterogêneo de fungos que causam uma variedade de doenças, incluindo feohifomicoses, cromoblastomicoses, micetomas e alergias. Espécies do gênero Cladosporium são relevantes no desenvolvimento de cromoblatomicoses, e se destacam como contaminantes de plantas. A toxicidade dos antifúngicos convencionais e o aumento da resistência aos esquemas terapêuticos utilizados impulsionam o estudo da atividade antifúngica de novas alternativas, incluindo as de fonte natural. Diante desse contexto, o objetivo deste trabalho foi avaliar a atividade antifúngica In vitro de sete óleos essenciais (Laurus nobilis L., Mentha arvensis, Mentha X piperita L., Mentha spicata, Ocimum basilicum L., Cymbopogon nardus L. Rendle e Origanum vulgare) e do fitoconstituinte citronelal sobre cepas de fungos dematiáceos. Neste estudo, os seguintes métodos foram utilizados: triagem microbiológica, determinação da Concentração Inibitória Mínima (CIM) e Concentração Fungicida Mínima (CFM), cinética de morte microbiana, inibição da germinação de conídios e avaliação de alterações morfológicas. Dentre os óleos essenciais testados, o de C. nardus demonstrou uma potente atividade antifúngica, inibindo o crescimento de 83,3% das cepas de fungos demáceos utilizadas. O Cymbopogon nardus L. Rendle (capim-citronela) pertence à família Poaceae, subfamília Panicoideae. O gênero Cymbopogon é constituído de oitenta e cinco espécies. O C. nardus apresenta constituição do óleo essencial com dois compostos majoritários: o citronelal e o geraniol. Citronelal é um monoterpeno, predominantemente formado pelo metabolismo secundário de plantas. O óleo essencial de C. nardus teve sua CIM e CFM estabelecidas em 64 μg/ mL e o citronelal em 32 μg/ mL. Tanto o óleo essencial de C. nardus quanto o citronelal inibiram de forma significativa o crescimento micelial radial das cepas testadas, nas concentrações CIM, CIMx2 e CIMx4, após 12 dias de exposição. Nas concentrações CIM50 (64 μg/ mL- óleo essencial e 32μg/mL -citronelal) e CIM90 (128 μg/mL - óleo essencial e 512μg/mL - citronelal), foram capazes de inibir de forma significativa a germinação dos conídios fúngicos de ambas as cepas testadas. A determinação do efeito do óleo essencial de C. nardus e do citronelal sobre a morfogênese das cepas de C. carrionii demonstrou que ambos foram capazes de induzir alterações morfológicas, como desenvolvimento de hifas tortuosas, finas e diminuição da conidiação, nas concentrações CIM, CIMx2 e CIMx4. Dessa forma, conclui-se que o óleo essencial de C. nardus e o seu fitoconstituinte citronelal mostraram pronunciada atividade antifúngica sobre as cepas de C. carrionii testadas, o que impulsiona o estudo de suas atividades antifúngicas In vivo, bem como a busca por formulações farmacêuticas a serem utilizadas para a terapia de algumas micoses, especialmente aquelas causadas por fungos demáceos.
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Rabelo, Diego de Moura. "Estudo fitoquímico e biológico de guatteria citriodora ducke". Universidade Federal do Amazonas, 2008. http://tede.ufam.edu.br/handle/tede/3332.
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Previous issue date: 2008-01-24Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
The Guatteria citriodora Ducke is an Amazon species known family Annonaceae, popularly as enviara amarela or laranjinha , that occurs in rain forest on land-firm, with distribution on the states of Amazonas and Pará, being found in Guiane and Suriname. The phytochemical study of stem bark of this plant resulted on isolation of three oxoaporphine alkaloids, O-methylmoschatoline, liriodenine and oxoputerine, common in Annonaceae, and previously obtained from species of Guatteria genus. Their identifications were accomplished through spectroscopic analyses (IR, RMN 1H, HSQC and HMBC) and by comparison with the data of the literature. The essential oil extracted from leaves was analyzed by GC/MS and presented as major constituents the monoterpenoids citronnelal (25.5%) and citronnelol (22.4%). The biological evaluation of this oil showed leishmanicidal activity in vitro against Leishmania guianensis (IC50=12.1±1.5 g/mL), and 94.5% of lethality against Artemia salina Leach, in the concentration of 500 g/mL. The species needs more research for the study of its application, for presenting biotechnical potential in its constituents.
A Guatteria citriodora Ducke é uma espécie amazônica da família Annonaceae, conhecida popularmente como envira-amarela ou laranjinha, a qual ocorre em floresta pluvial de terra firme com distribuição nos estados do Amazonas e Pará, bem como nas Guianas, Suriname, Bolívia, Equador, Colômbia, Peru e Venezuela. O estudo fitoquímico da casca do caule dessa planta resultou no isolamento de três alcalóides oxoaporfínicos, O-metilmoshatolina, liriodenina e oxoputerina, essas substâncias foram previamente isoladas e descritas em espécies do gênero Guatteria. A identificação desses compostos foi realizada por meio de técnicas espectroscópicas (IV, RMN 1H, HSQC e HMBC) e por comparação com dados da literatura. O óleo essencial extraído das folhas foi analisado por CG/EM e apresentou como constituintes majoritários os monoterpenóides citronelal (25,5%) e citronelol (22,4%). A avaliação biológica desse óleo apresentou atividade leishmanicida in vitro contra Leishmania guyanensis (CI50=12,1±1,5 g/mL), e 94,5% de letalidade frente à Artemia salina Leach, na concentração de 500 g/mL. A espécie necessita de mais pesquisa para o estudo de suas aplicabilidades, por apresentar potencial biotecnológico em seus constituintes.
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Silva, Jaqueline Maria Ramos da. "Epoxidação quimio-enzimática do citronelol e B-cariofileno". Florianópolis, SC, 2012. http://repositorio.ufsc.br/xmlui/handle/123456789/96427.
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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas. Programa de Pós-Graduação em Química.Made available in DSpace on 2012-10-26T11:57:09Z (GMT). No. of bitstreams: 1 301775.pdf: 1532162 bytes, checksum: 5f9da1e3cc2b06a41a8e3d8bbdfcb96b (MD5)
In this work, the chemoenzymatic epoxidation of terpenes citronellol and â-caryophyllene is reported. Some experimental conditions, such as the use of different lipases and mycelia, oxidizing agents (H2O2 or UHP), reaction time, acyl donor type, temperature (15-45°C) and the influence of the organic medium, including the use of ionic liquids (ILs) were evaluated. In the epoxidation of citronellol two products were obtained; namely citronellol oxide 43 and/or citronellol epoxide ester 47. Depending on the reaction conditions, the product 43 was obtained in conv. >99%. CAL-B was the most efficient catalyst. The highest conversions were achieved for the epoxide 43 at 20 and 25 °C, with conv. of 80% and 77%. The organic medium was one of the most important parameters in this reaction. Using chloroform or dichloromethane, product 43 was obtained in conversions >99% after 24 h. Using mixtures of organic solvents and ILs, the results were dependent on both the organic solvent and the counter ion type in IL. These parameters were also evaluated when â-caryophyllene was used as the substrate. Using this substrate two products, the mono-epoxide 44 and the di-epoxide 45, were formed. The use of several lipases from different sources was also evaluated, and CAL-B was the most efficient catalyst (conv. >99% in 44). By the use of commercial lipases (Amano PS-C I, F-AP15, Amano PS-C SD, Amano PS, Amano AY 30, Amano PS IM, M Amano 10, 20 Amano AK, Amano PS-C II, A Amano 12, Lipozyme RM IM, Lipozyme IM), the conversions in product 44 were of 16-27%; by using the native lipases LAN and LRO the conversions were 20-23% and using the mycelia UEA_06 and UEA_53, the conversions were 16 and 21%, in 24 h. The best oxidizing agent was H2O2 as compared to UHP, considering that the reaction occurred in a shorter time and only a small amount of the reagent was necessary to obtain 44 or 45 as unique products in high conv. (60 ->99%). Using 2.0 mmol of H2O2, CAL-B could be reused up to 5 times with minimal loss in the conversion degrees to 44 (93-90%). The organic solvents were also selective. By using n-hexane, the preferential formation of 44 was observed with conv. >99% after 8 and 24 h reaction. When ethyl acetate and toluene were used, the conversions were of >99% on 45 after 8 and 24h. It is worth of mentioning that the chemoenzymatic methodology used mild conditions and presented selectivity, as depending on the reaction conditions only one product could be obtained in good conversion degrees.
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Maharaj, Riddhi Anubhav. "The conversion of citronellal over sulphonated polystyrene resin catalysts". Master's thesis, University of Cape Town, 2016. http://hdl.handle.net/11427/20486.
Testo completoAbstract (sommario):
Citronellal was converted over sulphonated polystyrene resin catalysts of different acid loading. The catalysts had been prepared sulphonating a commercial polystyrene resin with sulfuric acid. Catalyst activities were screened in the liquid phase and in the gas phase in a temperature range of 50 to 110°C, varying space velocity. Catalyst activities (in terms of rates of citronellal conversion) followed the degree of sulphonation and were similar in both the environments, but apparently governed by external mass transfer control in the liquid phase or limited by the very low partial pressure of citronellal in the gas phase. No effect of the degree of sulphonation on selectivity was observed. [Please note: the fulltext of this thesis has been deferred to 9 June 2018]
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Förster-Fromme, Karin. "Der Citronellolstoffwechsel in Pseudomonaden - Funktionelle Zuordnung beteiligter Gene und deren Produkte". [S.l. : s.n.], 2008. http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-34550.
Testo completoAbstract (sommario):
Stuttgart, Universiẗat, Diss., 2008.Aus: Appl. Environ. Microbiol. 2006 Jul;72(7):4819-28, FEMS Microbiol. Lett. 2006 Nov;264(2):220-5, Microbiology. 2008 Mar;154(Pt 3):789-96, FEMS Microbiol. Lett. 2005 May 1;246(1):25-31.
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Höschle, Birgit. "Identifizierung zweier Gencluster (atuABCDEFGH, liuRABCDE) in Pseudomonas aeruginosa PAO1 und deren funktionelle Analyse im Metabolismus methylverzweigter Verbindungen". [S.l. : s.n.], 2006. http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-27099.
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Akhtar, Mohamed U. "Towards controlled release of a natural mosquito repellent from polymer matrices". Diss., University of Pretoria, 2014. http://hdl.handle.net/2263/46236.
Testo completoAbstract (sommario):
Malaria is still the most important parasitic disease in humans with most cases occurring in Sub-Saharan Africa (90% cases). It is transmitted via anopheles mosquitoes. Several vector control methods are available, e.g. long lasting insecticidal mosquito nets (LLINs), insecticide-treated nets (ITNs) and indoor residual spraying (IRS). However, they are effective only when a person is in-doors. Outdoor protection can be obtained for short periods (48-72 hours) using topical repellents. This preliminary study investigated the possibility to develop longer acting delivery forms based on polymer technology. The viability of two different approaches were considered for the controlled release of the natural repellent 3,7-dimethyloct-6-en-1-al (citronellal). The first idea was to dissolve the repellent in the polymer while controlling the rate of release by clay nanoplatelets dispersed in the matrix. Towards this, ethylene vinyl acetate (EVA) copolymer (18% VA) was modified with organically modified nanoclay. Release tests showed that this approach was not viable as only a small amount of repellent could be incorporated and it was lost within a day or two from thin polymer strands.
The second approach targeted the use of a polymer in which the repellent is not soluble at ordinary temperature but where solubility is achieved at high temperatures. In this case polyethylene was used as host polymer. It was shown that large quantities of repellent can be trapped inside the polymer matrix using the temperature induced phase separation method (TIPS). Scanning electron microscopy revealed that a microporous co-continuous phase structure was obtained by shock cooling homogeneous mixtures to temperatures well below the spinodal phase boundary curve.
The phase behaviour of the LLDPE-citronellal system was studied using cloud point determinations in a microscope fitted with a hot stage and by differential scanning calorimetry. The experimental data points on the bimodal phase envelope were used to fix parameter values of the Flory-Huggins equation. The latter was then used to predict the location of the spinodal lines. At 40 wt.% polymer the spinodal boundary is located at 96 C. However, experiments showed that quenching temperature of 5°C (i.e. the temperature of typical cooling baths used during filament extrusion) is sufficient to generate the desired microporous structure.Dissertation (MSc)--University of Pretoria, 2014.
tm2015
Chemical Engineering
MSc
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Martini, Viviane Quintino, Paulo Cesar de Jesus e Universidade Regional de Blumenau Programa de Pós-Graduação em Química. "Resolução do (±)-citronelol e ácido (±)-citronélico via esterificação enantiosseletiva catalisada pela lipase de candida antarctica /". reponame:Biblioteca Digital de Teses e Dissertações FURB, 2007. http://www.bc.furb.br/docs/DS/2007/326933_1_1.pdf.
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Medeiros, Cássio Ilan Soares. "Atividades Antifúngica e Toxicológica In Silico dos Enantiômeros (R)-(+)- e (S)-(-)-citronelal". Universidade Federal da Paraíba, 2016. http://tede.biblioteca.ufpb.br:8080/handle/tede/8809.
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arquivototal.pdf: 2056832 bytes, checksum: dd1f04e5a02bdef6bb3220514f057563 (MD5)Made available in DSpace on 2017-02-01T13:46:41Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2056832 bytes, checksum: dd1f04e5a02bdef6bb3220514f057563 (MD5) Previous issue date: 2016-10-25
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
The incidence of vulvovaginal fungal infections has increased dramatically over the last decades, therefore being the second most common cause of vulvovaginal candidiasis (VVC) placed after bacterial vaginosis diagnosed in 40% of the women with vaginal discharge. The increasing resistance of micro-oganismos pathogens to existing antimicrobial market has driven the search for new therapeutic alternatives, such as natural herbal products belonging to various families of the plant kingdom, such as Poaceae and Myrtaceae, which are presented as a viable solution due to the low cost and easy access of the population. Highlighted, the genus Cymbopogon and the Eucalyptus plants is one of the main sources of biologically active molecules, among them the monoterpenes holds a huge biological potential of human interest. However, the research of plant-derived compounds with pharmacological properties must always be attached to toxicity studies in order to show the absence of these substances harm to the human body. Given this context, it has studied the biological activity of enantiomers (R)-(+)- and (S)-(-)-citronellal against C. albicans and C. tropicalis strains derived from in vitro vulvovaginal secretions, as well as the parameters toxicological to predict the theoretical oral toxicity in silico. To achieve the antimicrobial in vitro studies; determination of minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) was used microdilution test. Also it was applied to disk diffusion technique on solid medium for comparative study of antifungal resistance/sensitivity profile used in the treatment of vulvovaginal candidiasis isolated and associated with monoterpenes studieds. The MIC's and MFC's of the (R)-(+)- and (S)-(-)-citronellal to 90% of fungal strains were respectively (R)MIC90% 16μg/mL and (R)MFC90% 32μg/mL; (S)MIC90% 64μg/mL and (S)MFC90% 128μg/mL (Strong antifungal activity against C. albicans and C. tropicalis). Were observed high resistance of C. albicans to fluconazole and itraconazole 12 (92.30%) strains. However, this resistance was reversed in 9 (75%) and 7 (58.33%) respectively, when combined with (R)-(+)-citronellal and 6 (50%) in combination with (S)-(-)-citronellal. Furthermore, it was also observed C. tropicalis high resistance to amphotericin B, itraconazole and miconazole. However, the resistance was reversed to amphotericin B and itraconazole, as a result of the synergistic effect in 2 (66.65%) of yeast. For miconazole resistance was reversed in 3 (100%) of the strains for both enantiomers. In the in silico analysis, both enantiomers have good oral bioavailability theoretically, however, a potential irritant was observed as possible toxic effect on these monoterpenes. In conclusion, these results suggest that the (R)-(+)- and (S)-(-)-citronellal have antimicrobial effect, and which also exert effect modifier activity when antifungal agents in combination. However, although presenting good oral bioavailability theoretically, the varied toxicological profile suggests the need to assess the risk-benefit of this compound in the production of a new antifungal drug, by conducting in vivo trials.
A incidência de infecções fúngicas vulvovaginais aumentou dramaticamente ao longo das últimas décadas, constituindo assim a segunda causa mais comum de candidíase vulvovaginal (CVV) após a vaginose bacteriana diagnosticada em 40% das mulheres com corrimento vaginal. O aumento da resistência dos micro-organismos patógenos aos antimicrobianos existentes no mercado tem impulsionado a busca de novas alternativas terapêuticas, como os produtos naturais a base de plantas pertencentes a várias famílias do reino vegetal, como por exemplo a Poaceae e a Myrtaceae, que se apresentam como uma solução viável devido ao baixo custo e fácil acesso da população. Em destaque, as plantas do gênero Cymbopogon e Eucalyptus constitui uma das principais fontes de moléculas biologicamente ativas, dentre elas os monoterpenos são detentores de um enorme potencial biológico de interesse humano. No entanto, as pesquisas de compostos derivados de plantas com propriedades farmacológicas devem sempre ser unida aos estudos toxicológicos, afim de se comprovar a ausência de malefícios destas substâncias ao organismo humano. Diante deste contexto, foi estudado a atividade biológica dos enantiômeros (R)-(+)- e (S)-(-)-citronelal contra cepas de C. albicans e C. tropicalis oriundas de secreções vulvovaginais in vitro, bem como os parâmetros toxicológicos para a previsão da toxicidade oral teórica in silico. Para a realização dos estudos antimicrobianos in vitro; determinação da concentração inibitória mínima (CIM) bem como da concentração fungicida mínima (CFM), utilizou-se o teste de microdiluição. Também foi aplicada a técnica de disco-difusão em meio sólido para estudo comparativo do perfil de resistência/sensibilidade a antifúngicos utilizados na terapêutica da candidíase vulvovaginal isolados e associados aos monoterpenos em estudo. As CIM’s e as CFM’s dos enantiômeros (R)-(+)- e (S)-(-)-citronelal para 90% das cepas fúngicas foram respectivamente (R)CIM90% 16μg/mL e (R)CFM90% 32 μg/mL; (S)CIM90% 64μg/mL e (S)CFM90% 128 μg/mL (forte atividade antifúngica contra C. albicans e C. tropicalis). Foram constatados alta resistência de C. albicans ao fluconazol e ao itraconazol 12 (92.30%) das cepas testadas. Mas, essa resistência foi revertida em 9 (75%) e 7 (58.33%) respectivamente, quando em associação com o (R)-(+)-citronelal e em 6 (50%) em combinação com o (S)-(-)-citronelal. Além disso, também foi observado alta resistência de C. tropicalis a anfotericina B, itraconazol e miconazol. Porém a resistência foi revertida para a anfotericina B e para o itraconazol, resultado do efeito sinérgico em 2 (66.65%) das leveduras. Para o miconazol a resistência foi revertida em 3 (100%) das cepas para ambos os enantiômeros. Na análise in silico, ambos os enantiômeros apresentaram boa biodisponibilidade oral teórica, no entanto, um potencial irritante foi observado como possível efeito tóxico para estes monoterpenos. Em conclusão, estes resultados sugerem que os enantiômeros (R)-(+)- e (S)-(-)-citronelal apresentam efeito antimicrobiano, e que também exercem efeito modificador de atividade aos agentes antifúngicos quando em combinação. No entanto, embora tenha apresentado boa biodisponibilidade oral teórica, o perfil toxicológico variado sugere a necessidade em avaliar o risco-benefício desse composto na produção de um novo medicamento antifúngico, por realização de ensaios in vivo.
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Silva, Alfredo Augusto Vasconcelos da. "Estudo comparativo das aÃÃes vasodilatadoras de (+)-Ãxido rosa, β-Citronelol e Geraniol em aorta de rato". Universidade Federal do CearÃ, 2017. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=19065.
Testo completoAbstract (sommario):
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico(+)-Ãxido rosa (OR), β-citronelol (BC) e geraniol (GE) sÃo monoterpenos quimicamente relacionados naturalmente encontrados em diversos Ãleos essenciais, como na rosa bÃlgara e Ãleo de gerÃnio. Enquanto as aÃÃes farmacolÃgicas do OR sÃo ainda escassas, alguns relatos preliminares apontam que BC e GE agem potencialmente como inibidores de canais de Ca2+ no mÃsculo liso vascular. Por isso, o objetivo deste estudo foi comparar os efeitos do OR, BC e GE na contratilidade da aorta isolada de ratos. Registros isomÃtricos foram obtidos a partir de anÃis de aorta atravÃs de sistema de aquisiÃÃo de dados. Em anÃis de aorta com endotÃlio intacto, OR, BC e GE (1 â 3000 ÂM) relaxaram a contraÃÃo induzida por fenilefrina com valores de CE50 [I.C. 95%] de 1715,9 [1386,6 â 2123,4], 342,6 [110,2 â 1065,8] e 930,8 [758,8 â 1141,7] ÂM, respectivamente. JÃ em contraÃÃo induzida por KCl (60 mM), OR teve CE50 de 550,6 [245,6 â 1234,4] ÂM, BC de 98,3 [42,8 â 225,7] ÂM e GE de 217,5 [156,4 â 302,5] ÂM. Os efeitos vasorrelaxantes dos monoterpenos sobre as contraÃÃes induzidas por fenilefrina ou KCl nÃo foram significativamente (P > 0,05, Mann-Whitney) alterados pela remoÃÃo do endotÃlio, tratamento com L-NAME ou tetraetilamÃnio. Os valores de CE50 dos monoterpenos nas preparaÃÃes prÃ-contraÃdas com Ãster de forbol (973,6 [389,7 â 2432,2] ÂM para OR; 77,8 [14,4 â 419,2] ÂM para BC e 151,2 [46,21 â 494,6] ÂM para GE) e U46619 (533,6 [212,4 â 1340,8] ÂM para OR, 106,7 [53,6 â 212,1] ÂM para BC e 386,8 [207,1 â 722,4] ÂM para GE), foram significantemente menores (p < 0,01, Mann-Whitney) do que os valores obtidos na prÃ-contraÃÃo induzida por fenilefrina em aorta.Em meio sem Ca2+ na presenÃa de KCl (60 mM), as contraÃÃes provocadas pela adiÃÃo de Ca2+ foram significativamente reduzidas por OR, BC e GE (a partir de 600ÂM), mas quando fenilefrina foi adicionada em lugar de K+, nÃo ocorreu diminuiÃÃo da magnitude da resposta contrÃtil. O presente estudo sugere que a atividade vasorrelaxante desses monoterpenos em aorta de rato envolve inibiÃÃo de canais de cÃlcio operados por voltagem na seguinte ordem de potÃncia farmacolÃgica: BC > GE > OR.
(+)-Rose oxide (OR), β-citronellol (BC) and geraniol (GE) are chemically related monoterpenes found naturally in several essential oils, such as in bulgarian rose and geranium oil. While the pharmacological actions of OR are still scarce, some reports show that BC and GE act potentially as inhibitors of Ca2+ channels in vascular smooth muscle. As chemically related molecules, the objective of this study was to compare the effects of OR, BC and GE on aortic contractility isolated from rats. Isometric records were obtained from aortic rings through a data acquisition system. In aortic rings with intact endothelium, OR, BC and GE (1 - 3000 μM) relaxed the contraction induced by phenylephrine with EC50 values [I.C. 95%] of 1715.9 [1386.6-2123.4], 342.6 [110.2-1065.8] and 930.8 [758.8-1141.7] μM, respectively. Already in KCl induced contraction (60 mM) the OR had EC50 of 550.6 [245.6-1234.4] μM, BC of 98.3 [42.8 - 225.7] μM and GE of 217,5 [156.4-302.5] μM. The vasorelaxant effects of monoterpenes on contractions induced by phenylephrine or KCl were not significantly (P> 0.05, Mann-Whitney) altered by endothelial removal, treatment with L-NAME or tetraethylammonium. The EC50 values of the monoterpenes in phorbol ester pre-contracted preparations (973.6 [389.7-2432.2] μM for OR, 77.8 [14.4-419.2] μM for BC and 151, 2 [46.21 - 494.6] μM for GE) and U46619 (533.6 [212.4-1340.8] μM for OR, 106.7 [53.6 - 212.1] μM for BC and 386,8 [207.1 - 722.4] μM for GE), were significantly lower (p <0.01, Mann-Whitney) than the values obtained in pre-contraction induced by phenylephrine in the aorta. In Ca2+-free medium in the presence of KCl (60 mM), contractions caused by the addition of Ca2+ were significantly reduced by OR, BC and GE (from 600μM), but when phenylephrine was added instead of K+, there was no decrease in the magnitude of the contractile response. The present study suggests that the vasorelaxant activity of these monoterpenes in rat aorta involves inhibition of voltage-operated calcium channels in the following order of pharmacological potency: BC > GE > OR.
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Silva, Alfredo Augusto Vasconcelos da. "Estudo comparativo das ações vasodilatadoras de (+)-Óxido rosa, β-Citronelol e Geraniol em aorta de rato". reponame:Repositório Institucional da UFC, 2017. http://www.repositorio.ufc.br/handle/riufc/22409.
Testo completoAbstract (sommario):
SILVA, A. A. V. Estudo comparativo das ações vasodilatadoras de (+)-Óxido rosa, β-Citronelol e Geraniol em aorta de rato. 2017. 60 f. Dissertação (Mestrado em Farmacologia) - Faculdade de Farmácia, Odontologia e Enfermagem, Universidade Federal do Ceará, Fortaleza, 2017.Submitted by Erika Fernandes (erikaleitefernandes@gmail.com) on 2017-03-27T16:20:34Z No. of bitstreams: 1 2017_dis_aavsilva.pdf: 1313833 bytes, checksum: 79490ce67b12562ba8a4d3c371215227 (MD5)
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(+)-Rose oxide (OR), β-citronellol (BC) and geraniol (GE) are chemically related monoterpenes found naturally in several essential oils, such as in bulgarian rose and geranium oil. While the pharmacological actions of OR are still scarce, some reports show that BC and GE act potentially as inhibitors of Ca2+ channels in vascular smooth muscle. As chemically related molecules, the objective of this study was to compare the effects of OR, BC and GE on aortic contractility isolated from rats. Isometric records were obtained from aortic rings through a data acquisition system. In aortic rings with intact endothelium, OR, BC and GE (1 - 3000 μM) relaxed the contraction induced by phenylephrine with EC50 values [I.C. 95%] of 1715.9 [1386.6-2123.4], 342.6 [110.2-1065.8] and 930.8 [758.8-1141.7] μM, respectively. Already in KCl induced contraction (60 mM) the OR had EC50 of 550.6 [245.6-1234.4] μM, BC of 98.3 [42.8 - 225.7] μM and GE of 217,5 [156.4-302.5] μM. The vasorelaxant effects of monoterpenes on contractions induced by phenylephrine or KCl were not significantly (P> 0.05, Mann-Whitney) altered by endothelial removal, treatment with L-NAME or tetraethylammonium. The EC50 values of the monoterpenes in phorbol ester pre-contracted preparations (973.6 [389.7-2432.2] μM for OR, 77.8 [14.4-419.2] μM for BC and 151, 2 [46.21 - 494.6] μM for GE) and U46619 (533.6 [212.4-1340.8] μM for OR, 106.7 [53.6 - 212.1] μM for BC and 386,8 [207.1 - 722.4] μM for GE), were significantly lower (p <0.01, Mann-Whitney) than the values obtained in pre-contraction induced by phenylephrine in the aorta. In Ca2+-free medium in the presence of KCl (60 mM), contractions caused by the addition of Ca2+ were significantly reduced by OR, BC and GE (from 600μM), but when phenylephrine was added instead of K+, there was no decrease in the magnitude of the contractile response. The present study suggests that the vasorelaxant activity of these monoterpenes in rat aorta involves inhibition of voltage-operated calcium channels in the following order of pharmacological potency: BC > GE > OR.
(+)-Óxido rosa (OR), β-citronelol (BC) e geraniol (GE) são monoterpenos quimicamente relacionados naturalmente encontrados em diversos óleos essenciais, como na rosa búlgara e óleo de gerânio. Enquanto as ações farmacológicas do OR são ainda escassas, alguns relatos preliminares apontam que BC e GE agem potencialmente como inibidores de canais de Ca2+ no músculo liso vascular. Por isso, o objetivo deste estudo foi comparar os efeitos do OR, BC e GE na contratilidade da aorta isolada de ratos. Registros isométricos foram obtidos a partir de anéis de aorta através de sistema de aquisição de dados. Em anéis de aorta com endotélio intacto, OR, BC e GE (1 – 3000 µM) relaxaram a contração induzida por fenilefrina com valores de CE50 [I.C. 95%] de 1715,9 [1386,6 – 2123,4], 342,6 [110,2 – 1065,8] e 930,8 [758,8 – 1141,7] µM, respectivamente. Já em contração induzida por KCl (60 mM), OR teve CE50 de 550,6 [245,6 – 1234,4] µM, BC de 98,3 [42,8 – 225,7] µM e GE de 217,5 [156,4 – 302,5] µM. Os efeitos vasorrelaxantes dos monoterpenos sobre as contrações induzidas por fenilefrina ou KCl não foram significativamente (P > 0,05, Mann-Whitney) alterados pela remoção do endotélio, tratamento com L-NAME ou tetraetilamônio. Os valores de CE50 dos monoterpenos nas preparações pré-contraídas com éster de forbol (973,6 [389,7 – 2432,2] µM para OR; 77,8 [14,4 – 419,2] µM para BC e 151,2 [46,21 – 494,6] µM para GE) e U46619 (533,6 [212,4 – 1340,8] µM para OR, 106,7 [53,6 – 212,1] µM para BC e 386,8 [207,1 – 722,4] µM para GE), foram significantemente menores (p < 0,01, Mann-Whitney) do que os valores obtidos na pré-contração induzida por fenilefrina em aorta.Em meio sem Ca2+ na presença de KCl (60 mM), as contrações provocadas pela adição de Ca2+ foram significativamente reduzidas por OR, BC e GE (a partir de 600µM), mas quando fenilefrina foi adicionada em lugar de K+, não ocorreu diminuição da magnitude da resposta contrátil. O presente estudo sugere que a atividade vasorrelaxante desses monoterpenos em aorta de rato envolve inibição de canais de cálcio operados por voltagem na seguinte ordem de potência farmacológica: BC > GE > OR.
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Burger, Kirstin. "Evaluation of eucalyptus citriodora derived p-menthane-3,8-diol-citronellal acetal as a bio-plasticizer for cosmetic application". Thesis, Nelson Mandela Metropolitan University, 2013. http://hdl.handle.net/10948/d1014080.
Testo completoAbstract (sommario):
Plasticizers are generally added to cosmetic and personal care products to improve the filmforming abilities of the product and increase flexibility of the film formed on the skin or hair surface. For example, plasticizers are present in perfumes to prolong the release of the specific scent, which is the ultimate goal in a good quality perfume. Plasticizers in nail varnishes prevent chipping, improve the aesthetics by adhering to the keratin in the nail which means the coating stays on for much longer, which is the ultimate goal in nail products. Plasticizers improve the gloss, resist chipping and allow quick drying time. Therefore it can be seen that plasticizers play a vital role in personal care products like perfumes and nail varnishes. Certain plasticizers e.g. phthalates, can cause problems associated with human health and can harm the environment. They are easily available and large volumes can be obtained at a low cost. These phthalates, for example, di-butyl phthalate (DBP) have been identified as carcinogenic. Nowadays the occurrence of cancer is rapidly increasing. The plasticizers present in a large number of consumer and personal care products, can possibly be linked to the ever increasing reports of cancer. Therefore a substitute to the traditional phthalate plasticizers must be investigated. The aim of this research is to produce a plasticizer derived from naturally occurring Eucalyptus oil, which can be used to replace the existing plasticizers in cosmetic formulations. Para-menthane-3,8-diol (PMD), occurring naturally in the oil from the tree, Eucalyptus citriodora, forms an acetal with citronellal (PMD, acetal, citronellal all occur naturally in the oil). It has been previously shown that PMD-citronellal acetal will exhibit plasticizing properties similar to conventional plasticizers. The objective was to enhance the formation of the acetal in the Eucalyptus oil by reacting it with excess PMD. An effective synthesis method for the PMD-citronellal acetal enriched oil (~73.8 percent) was determined from optimization experiments. The physical characterisation of the PMD-citronellal acetal enriched oil was done and compared with that of DBP. The acetal-enriched oil had a lower density, slightly higher solubility in water (at 25°C), lower refractive index (Brix percent) and a higher boiling point (350°C) than DBP. The physical characteristics of the Eucalyptus oil source and the acetal-enriched Eucalyptus oil were very similar. This can be expected as the Eucalyptus oil consists of ~84.3 percent Citronellal, ~ 1.3 percent PMD and 2.7 percent PMD-citronellal acetal. In this study the effectiveness of the acetal-enriched Eucalyptus oil (referred to from now on as the bio-plasticizer) was compared to a conventional plasticizer such as di-butyl phthalate (DBP), commonly used in cosmetic products. Two cosmetic formulations were produced: a nail varnish and a perfume formulation. Various tests were performed on these formulations to investigate the plasticizing properties of the bio-plasticizer. The objectives were to determine if the natural plasticizer is as effective as the potentially carcinogenic phthalate plasticizers and can be used as a substitute for the phthalates in personal care products. The results indicate that the bio-plasticizer does behave similarly to di-butyl phthalate, however, the effectiveness of the bio-plasticizer is lower than that of di-butyl phthalate. As the viscosity of the synthesized oil was high, this affected the overall consistency of the products. A more viscous nail varnish and perfume was produced in comparison to the DBP counterpart. The stability of the bio-plasticizer in the cosmetic formulations of nail varnish and perfume was also investigated. The cosmetic products were incubated at 0°C, 25°C and 40°C over a period of two months. Any changes in colour, odour, pH, refractive index, separation and plasticizer peak change in the gas chromatogram trace were recorded. It was determined that the PMD-citronellal acetal-enriched oil was relatively unstable under elevated temperatures and light intensity. Storage under higher temperatures (40°C) tends to increase the acidity. Therefore the bio-plasticizer must be placed in a closed, covered bottle and stored in an environment away from light and elevated temperatures. According to the gas chromatogram peaks, it was clear that both the bio-plasticizer and the DBP were more unstable in the perfume formulation than in the nail polish and were especially sensitive to light when in the perfume. This could possibly be due to the interaction with the fragrance molecule, p-anisaldehyde.
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Ribeiro, Filho Helder Veras. "Efeitos cardiorrespiratórios do β-citronelol : envolvimento de fibras aferentes vagais e ação direta em músculos liso e cardíaco". reponame:Repositório Institucional da UFC, 2015. http://www.repositorio.ufc.br/handle/riufc/12852.
Testo completoAbstract (sommario):
RIBEIRO FILHO, Helder Veras. Efeitos cardiorrespiratórios do β-citronelol : envolvimento de fibras aferentes vagais e ação direta em músculos liso e cardíaco. 2015. 79 f. Dissertação (Mestrado em Farmacologia) – Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, 2015.Submitted by denise santos (denise.santos@ufc.br) on 2015-06-17T13:39:54Z No. of bitstreams: 1 2015_dis_hvribeiro filho.pdf: 2922834 bytes, checksum: 90787770a1d124b3e506577d71616b1b (MD5)
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β-Citronellol is a monoterpene found in the essential oil of various aromatic plants used in folk medicine to treat hypertension such as Cymbopogon citratus. β-Citronellol possesses hypotensive and vasorelaxant properties, but the mechanism of such effects remains unclear. Therefore, the present study was undertaken to address this issue in normotensive rats. For in vivo experiments, male Wistar rats were subjected to catheterization of the left femoral artery and vein for mean arterial pressure monitoring and drug injection, respectively. Electrodes allowed heart rate recordings and some groups of rats were tracheostomized for respiratory rate analysis. For in vitro experiments, right and left atria, and mesenteric artery rings were suspended in organ baths at physiological conditions. In urethane-anesthetized rats, intravenous (i.v.) injections of β-citronellol (5 and 10 mg/kg) caused biphasic (phase 1 and phase 2) hypotension, bradycardia and apnea responses. Biphasic responses was observed also following i.v. injection of β-citronellol (5, 10 and 20 mg/kg) in unanesthetized rats. Phase 1 of this triad (onset time of 1-2 s) was abolished by bilateral vagotomy (BV), perineural treatment with capsaicin (PNT) or pretreatment with methylatropine (MA, i.v.), but remained unaltered by i.v. pretreatment with capsazepine, ondansetron, suramin or HC-030031. Phase 1 responses was absent when β-citronellol was injected into the left ventricle. The delayed phase 2 of bradycardia was also partially reduced by BV, PNT or MA while the apnea component of this phase 2 was only abolished by suramin. In atrial preparations, β-citronellol induced chronotropic and inotropic negative responses, an effect that was related to neither muscarinic and adrenergic receptor activation nor to altered calcium influx. In both endothelium-intact and denuded mesenteric artery rings, β-citronellol fully relaxed phenylephrine-induced contractions in a concentration-dependent manner and with equal potency. These findings reveal that the effects evoked by β-citronellol induced vago-vagal reflex due to stimulation of vagal pulmonary afferents, an effect that seems not involving TRPV1, TRPA1, 5-HT3, or P2X receptors. Phase 2 hypotensive and bradycardiac responses to β-citronellol appears resulting from a direct vasodilatory effect upon vascular smooth muscle and cardiac depressor action, respectively. Furthermore, P2X receptors seem to be involved in the mediation of phase 2 apneic response to this acyclic monoterpene.
β-Citronelol é um monoterpeno encontrado no óleo essencial de diversas plantas aromáticas utilizadas na medicina popular para tratar hipertensão, como a Cymbopogon citratus. O β-citronelol possui propriedades hipotensoras e vasorrelaxantes, porém seu mecanismo ainda não está claro. Portanto, o presente estudo foi realizado para abordar essa questão em ratos normotensos. Para os experimentos in vivo, ratos Wistar macho foram submetidos a cateterização da artéria e veia femoral esquerda para registro da pressão arterial média e para administração de substâncias, respectivamente. Eletrodos permitiram o registro da frequência cardíaca e certos grupos de animais foram traqueostomizados para análise da frequência respiratória. Para os experimentos in vitro, os átrios direito e esquerdo, e anéis de artéria mesentérica foram suspensos em cubas para órgãos isolados sob condições fisiológicas. Em ratos anestesiados com uretana, injeções intravenosas (i.v.) de β-citronelol (5 e 10 mg/kg) causaram hipotensão, bradicardia e apneia em duas fases (fase 1 e fase 2), assim como em animais acordados (5, 10 e 20 mg/kg). A fase 1 dessa tríade (1 – 2 s de latência), foi abolida pela vagotomia bilateral (BV), pelo tratamento perineural com capsaicina (TP) ou pelo pré-tratamento com metilatropina (MA, i.v.), assim como pela injeção do β-citronelol dentro do ventrículo esquerdo, mas manteve-se inalterada pelo pré-tratamento i.v. com capsazepina, ondansetrona, suramina ou HC-030031. A fase 2 tardia de bradicardia foi também reduzida pela BV, TP ou MA, enquanto que a apneia de fase 2 foi abolida apenas pela suramina. Em preparações atriais, o β-citronelol induziu efeito cronotrópico e inotrópico negativos, os quais não parecem estar envolvidos com receptores muscarínicos ou adrenérgicos, ou alterações no influxo de cálcio. Em anéis de artéria mesentérica, com e sem endotélio, o β-citronelol relaxou totalmente pré-contrações de fenilefrina com equiparável potência. Esses resultados revelam que a fase 1 de efeitos do β-citronelol origina-se através de um reflexo vago-vagal resultante da estimulação de aferências pulmonares vagais, que parecem não envolver receptores TRPV1, TRPA1, 5-HT3 ou P2X. A fase 2 de hipotensão e bradicardia parece resultar de uma ação de vasodilatação direta e de um efeito cardíaco depressor, respectivamente. Além disso, receptores P2X parecem estar envolvidos na mediação da resposta de fase 2 de apneia induzida por esse monoterpeno acíclico.
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Oliveira, Filho Jaires Gomes de. "Avaliação do papel repelente de voláteis isolados no odor de cães da raça Beagle contra o carrapato Rhipicephalus sanguineus (Acari: Ixodidae)". Universidade Federal de Goiás, 2014. http://repositorio.bc.ufg.br/tede/handle/tede/4117.
Testo completoAbstract (sommario):
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Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq
Ticks are arthropods of great importance in public health, due to the transmission of many pathogens. Rhipicephalus sanguineus parasites mainly dogs. It is known that Beagle dogs are less susceptible to R. sanguineus than English Cocker Spaniel, and still have resistance patterns linked to immunity. The lower susceptibility of Beagle dogs is due to chemical compounds they produce, which act in reducing the parasitic load of R. sanguineus on these animals. Given that this research aimed to verify the chemical repellency against R. sanguineus of compounds that have been identified in the odor of resistant dogs, and synthetic repellent compounds to other tick species. For testing chemical repellency two tests were used, the Petri dish and the Y-olfactometer. Five compounds identified in Beagle odors were selected and tested: 2 - hexanone, nonane, decane, undecane and benzaldehyde, the compound of botanical origin β-citronellol and the standard repellent DEET (N,N-diethyl-3-methylbenzamide). These compounds were tested alone and also two mixtures were evaluated: benzaldehyde and 2-hexanone (1:1), and benzaldehyde, 2-hexanone and undecane (1:1:1). All these compounds were prepared in a stock solution of 7.2 % ( ≈ 0.200 mg/cm²) and two lower concentrations were also tested: 0.100 and 0.050 mg/cm². DEET was repellent in the two highest concentrations and 68.33 to 86.67% of the ticks were found in untreated areas in different time points. At the concentration of 0.050 mg/cm² ticks were distributed similarly (without significant difference) in both areas. β-citronellol was the only compound tested that was repellent at all times and concentrations tested. The percentage of ticks in untreated areas ranged from 73.33 to 93.33 %. When compared β-citronellol with DEET the first compound was more effective at repelling the adults of R. sanguineus. For benzaldehyde, 30 minutes at a concentration of 0.200 mg/cm² a percentage of 63.33 % of ticks was observed in the untreated area. Percentage of 76.67 was observed after 5 min. at a concentration of 0.050 mg/cm². 2-hexanone was repellent at 30 min. at a concentration of 0.200 mg/cm² at 10 min. at a concentration of 0.100 mg/cm² and 30 minutes at a concentration of 0.050 mg/cm². For undecane a rate of 65.00% of ticks was observed in the untreated area in one moment of testing, the highest concentration during the first 5 min. of the evaluation. Nonane and decane not were not repellent at any of the concentrations and time intervals. The blend benzaldehyde + 2-hexanone was repellent in the three highest concentrations in almost all evaluated times, including in the olfactometer testing. During the whole test this mixture showed statistical similarity when compared with DEET. The addition of undecane to this blend did not potentiate its repellent power. The main result was the finding of natural repellents in resistant dogs to the tick R. sanguineus.
Carrapatos são artrópodes de grande importância dentro da saúde pública, devido à transmissão de inúmeros patógenos. Rhipicephalus sanguineus parasita principalmente cães. Sabe-se que cães da raça Beagle são menos susceptíveis ao R. sanguineus que cães Cocker Inglês, e ainda apresentam padrões de resistência ligados a imunidade. A menor susceptibilidade de cães Beagle está ligada a compostos químicos que estes produzem, os quais atuam na diminuição da carga parasitária de R. sanguineus sobre estes animais. Sabendo-se disso com esta pesquisa objetivou-se verificar a repelência química de compostos que foram identificados no odor de cães resistentes, além de compostos sintéticos repelentes para outros carrapatos, contra o R. sanguineus. Para os testes de repelência química foram utilizados dois ensaios de repelência, o da placa de Petri e do olfatômetro em Y. Foram testados cinco compostos com provável poder repelente e identificados nos odores de Beagle (2-hexanona, nonano, decano, undecano e benzaldeído), o composto de origem botânica β-citronelol e o repelente padrão DEET (N,N-dietil-3-metilbenzamida). Além destes compostos testados isoladamente, duas misturas foram avaliadas: benzaldeído e 2 -hexanona (1:1), e benzaldeído, 2-hexanona e undecano (1:1:1) Todos estes compostos foram formulados a partir de uma solução mãe de 7,2% (≈ 0,200 mg/cm²) da qual foi obtida posteriormente outras duas concentrações (0,100 e 0,050 mg/cm²). O DEET foi repelente nas duas maiores concentrações, sendo que 68,33 a 86,67% dos carrapatos foram encontrados nas áreas não tratadas, nos diferentes tempos de observação. Na concentração de 0,050 mg/cm² os carrapatos se distribuíram similarmente (sem diferença significativa) em ambas as áreas. β-citronelol foi o único composto testado que foi repelente em todos os tempos e concentrações testados. Os percentuais de carrapatos nas áreas não tratadas variaram de 73,33 a 93,33%. Quando comparado com o DEET o β-citronelol foi mais eficiente em repelir os adultos de R. sanguineus. Para o benzaldeido, aos 30 minutos, na concentração de 0,200 mg/cm² foi observado um percentual de 63,33% de carrapatos na área não tratada. Percentual de 76,67 foi observado aos cinco minutos, na concentração de 0,050 mg/cm². A 2-hexanona foi repelente aos 30 minutos, na concentração de 0,200 mg/cm², aos 10 minutos, na concentração de 0,100 mg/cm² e aos 30 minutos, na concentração de 0,050 mg/cm². Para o undecano foi observado um percentual de 65,00 de carrapatos na área não tratada em apenas um momento dos testes, na maior concentração, durante os primeiros cinco minutos de avaliação. Nonano e decano não causaram qualquer repelência para os carrapatos testados, em qualquer uma das concentrações ou intervalos de tempo avaliados. A mistura benzaldeido + 2-hexanona foi repelente nas três maiores concentrações, em quase todos os tempos avaliados, inclusive no teste de olfatometria. Durante todo o teste esta mistura mostrou semelhança estatística quando comparada com o DEET. A adição de undecano a esta mistura não potencializou o seu poder repelente. O principal resultado obtido foi a constatação da presença de repelentes naturais em cães resistentes ao carrapato R. sanguineus.
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Costa, Aratã Oliveira Cortez. "Estudo in vitro e in silico da atividade antifúngica dos isômeros r-(+) e s-(-)citronelal sobre fungos do gênero cryptococcus". Universidade Federal da Paraíba, 2017. http://tede.biblioteca.ufpb.br:8080/handle/tede/9471.
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COSTA, A.O.C. In vitro and in silico evaluation of the antifungal activity of the R- (+) and S-(-) citronelal isomers, aginst fungi of the genus Cryptococcus. 2017. 52f. Dissertação (Pós-graduação em Produtos Naturais e Sintéticos Bioativos, Farmacologia). UFPB/CCS – João Pessoa – PB. Cryptococcus neoformans is an opportunistic pathogenic yeast with a wide geographical distribution, capable to infect the most varied types of animals. In humans, cryptococcosis mainly affects the central nervous system and lungs, less frequently the skin, presenting in general a serious and fatal evolution. Individuals with deficient immune systems are more likely to develop cryptococcosis, especially those afflicted with the human immunodeficiency virus. The conventional treatment of cryptococcosis uses potentially toxic antifungals for long periods and they have been target of resistance of these microorganisms, besides the high costs with the treatment. Given this panorama, the search for natural products with antifungal properties has been a promising alternative, with great attention of the students regarding the analysis of the essential oils and their constituents. Thus, the present research aimed to evaluate the biological effect of the R and S isomers of the citronellal phytoconstituent on fungi of the genus Cryptococcus, which could lead to the discovery of a molecule to the development of a new antifungal, besides contributing to obtain more information on the pharmacological potential of this phytoconstituent. MIC and MFC were determined, of the compounds, being 64 and 64 the values for R - (+) citronellal respectively, and 256 and 512, respectively, for citronellal S - (-), on fungi of the genus Cryptococcus; The antifungigram of the strains of Cryptococcus sp. was carried out with the antifungal agents amphotericin B, fluconazole and fluorocytosine where a resistance of fluconazole and flucytosine was observed; This study investigated the possible interference of monoterpenes in the study associated with the activity of these antifungal agents, noting that citronellal R did not present an apparent synergic effect, whereas S showed a much more synergistic effect, even capable of inhibiting the resistance caused by fluconazole; The microbial death curve of the R - (+) and S - (-) isomers of the citronellal phytoconstituent was determined on a previously chosen strain (FGF-3) and the fungicidal effects of the citronellal S isomer and concentration dependent fungicidal effect Of R citronelal; Its in silico variables were of good prospecting. In conclusion, the substances exhibited a good biological activity and correlation with other antifungal agents, showing synergistic effects in the association study and their in silico variables were well prospective, thus characterizing these fully viable substances to be continued their studies.
Cryptococcus neoformans é uma levedura patogênica oportunista, com ampla distribuição geográfica, capaz de infectar os mais variados tipos de animais. No homem, a criptococose acomete principalmente o sistema nervoso central e pulmões, com menor frequência a pele, apresentando-se de uma forma geral com evolução grave e fatal. Indivíduos com o sistema imunológico comprometido são mais susceptíveis de desenvolver a criptococose, principalmente os acometidos pelo vírus da imunodeficiência humana. O tratamento convencional da criptococose utiliza antifúngicos potencialmente tóxicos por longos períodos e que vêm sendo alvo de resistência desses micro-organismos, além dos elevados custos com o tratamento. Diante desse panorama, a busca por produtos naturais com propriedades antifúngicas têm sido uma alternativa promissora, com grande atenção dos estudiosos quanto à análise dos óleos essenciais e seus constituintes. Dessa forma, a atual pesquisa, teve por finalidade avaliar o efeito biológico dos isômeros R e S do fitoconstituinte citronelal, sobre fungos do gênero Cryptococcus, o que poderá conduzir à descoberta de uma molécula ao desenvolvimento de um novo antifúngico, além disso, contribuir para a obtenção de maiores informações sobre o potencial farmacológico desse fitoconstituinte. Foi determinada CIM e a CFM, dos compostos sendo 64 e 64 os valores para o R-(+) citronelal respectivamente, e 256 e 512, respectivamente, para o S-(-) citronelal, sobre fungos do gênero Cryptococcus; Foi realizado o antifungigrama das cepas de Cryptococcus Sp. com os antifúngicos anfotericina B, fluconazol e fluorcitosina onde observou-se uma resistência por parete do fluconazol e da flucitosina; Com isso foi investigado a possível interferência dos monoterpenos em estudo associados à atividade desses antifúngicos, observando que o R citronelal não apresentou efeito sinérgico aparente, enquanto o S apresentou um efeito bem mais sinérgico, capaz ate de inibir as resistências causadas com o fluconazol; Foi determinada a curva de morte microbiana dos isômeros R-(+) e S-(-) do fitoconstituinte citronelal, sobre uma cepa previamente escolhida (FGF-3) e foram observados os efeitos fungicidas do isômero S citronelal e efeito fungicida dependente de concentração do R citronelal; suas variáveis In silico foram de boa prospecção. Concluindo que as substancias exibiram uma boa atividade biológica e correlação com outros antifúngicos, apresentando efeitos sinérgicos no estudo de associação e suas variáveis In silico foram de boa prospecção, caracterizando assim essas substancias totalmente viáveis para que sejam continuados seus estudos.
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Teinz, Katharina. "Edelmetallbeladene Aluminiumhydroxidfluoride als neue heterogene Katalysatoren". Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2012. http://dx.doi.org/10.18452/16627.
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Hauptaufgabe dieser Promotionsarbeit war es, eine neue Sol-Gel basierte Syntheseroute zur Darstellung edelmetallbeladener (Pd, Pt, Ag und Au) Aluminiumhydroxidfluoride zu entwickeln. Derartige Katalysatoren besitzen sowohl Lewis- als auch Brønsted-saure, sowie hydrogenierungsaktive Zentren. Solche multifunktionellen Katalysatoren können für mehrstufige Umsetzungen von Substraten in Eintopfverfahren eingesetzt werden. Das Potential der dargestellten Katalysatoren wurde in der zweistufigen Umsetzung von Citronellal zu Mentholen und der dreistufigen Reaktion von Citral zu Mentholen gezeigt.The main aim of this thesis was to develop a new sol gel based synthesis route to noble metal loaded (Pd, Pt, Ag and Au) aluminium hydroxide fluorides. These catalysts provide Lewis as well as Brønsted acidity and hydrogenation ability. Those multifunctional catalysts can be used for multi step conversions of substrates performed in a one pot process. The potential of the synthesized catalysts was shown in the two step conversion of citronellal to menthols and in the three step conversion of citral to menthols.
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Theodorou, Konstantinos. "Carbon dioxide enhanced oil recovery from the Citronelle Oil Field and carbon sequestration in the Donovan sand, southwest Alabama". Thesis, The University of Alabama at Birmingham, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=3591675.
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Capturing carbon dioxide (CO2) from stationary sources and injecting it into deep underground geologic formations has been identified as a viable method for reducing carbon emissions to the atmosphere. Sedimentary rocks, such as sandstones overlain by shales or evaporites, are the preferred formations because their morphology and structure provide pore space, and containment for the long term storage of CO2. Sandstone formations have also served as repositories to migrating hydrocarbons, and are the sites of many oil recovery operations. For many depleted oil reservoirs, secondary waterflooding recovery methods are no longer efficient or economically viable, hence the application of tertiary CO2 enhanced oil recovery (CO 2-EOR) followed by CO2 storage is an attractive and cost effective business plan.
Citronelle Oil Field, located in southwest Alabama, is the largest and longest producing sandstone oil reservoir in the state, having produced more than 170 million barrels of oil from its estimated 500 million barrels of original oil in place, since its discovery in 1955. The field is in the later stages of secondary recovery by waterflooding and daily oil production has declined considerably. The field is comprised of the Upper and Lower Donovan hydrocarbon bearing sandstones, which are separated by the saline-water-bearing sandstones of the Middle Donovan. The Ferry Lake Anhydrite, which overlies the three sections, serves as their caprock.
The present work is focused on an investigation of the feasibility of a CO2-EOR project for the Citronelle Oil Field and the use of the Middle Donovan for long term CO2 storage. A set of static calculations, based on estimation methods which were retrieved from publications in the field, was followed by computer simulations using MASTER 3.0, TOUGH2-ECO2N, and TOUGHREACT. Results using MASTER 3.0, for simulation of CO2-EOR, indicated that nearly 50 million barrels of additional oil could be produced by tertiary recovery. Results using TOUGH2-ECO2N and TOUGHREACT, for the simulations of CO2 storage, indicated that 159 million metric tons (175 short tons) of CO2 could be stored in the Middle Donovan formation. An investigation into possible CO2 leakage from the reservoirs indicated that the Ferry Lake Anhydrite serves as a very reliable long term storage seal.
The present work can serve as a template for preliminary assessment of tertiary oil recovery and CO2 storage of similar oil reservoirs and saline-water formations.
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Vasconcelos, Thiago Brasileiro de. "Efeitos antiespasmÃdico e miorrelaxante do β-citronelol em mÃsculo liso traqueal de ratos: potencial aÃÃo na hiperreatividade apÃs desafio antigÃnico e elucidaÃÃo do mecanismo de aÃÃo". Universidade Federal do CearÃ, 2013. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=11503.
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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgicoO β-citronelol à um Ãlcool monoterpÃnico de ocorrÃncia natural em vÃrios Ãleos essenciais como o Ãleo de citronela (obtido de Cymbopogon winterianus), de ampla utilizaÃÃo popular por suas propriedades repelentes de insetos. Recentemente, a esta molÃcula tem sido atribuÃdas outras propriedades que envolvem atividade antibacteriana, antifÃngica, antiespasmÃdica, hipotensora e vasorrelaxante. Sendo assim, objetivamos estudar suas possÃveis aÃÃes no comportamento motor do mÃsculo liso do sistema respiratÃrio de ratos Wistar. Os animais considerados nesse estudo foram divididos em 04 grupos: controle, sensibilizado, desafiado e tratado, em seguida, registros isomÃtricos, in vitro, foram obtidos a partir de anÃis isolados de traqueia. A inalaÃÃo de β-citronelol (300 ÂM) preveniu a hiperreatividade traqueal mediante a adiÃÃo de K+ ou ACh em animais submetidos a um modelo de asma, no entanto, a adiÃÃo cumulativa de β-citronelol (10 a 1000 ÂM), na cuba para ÃrgÃos isolados, nÃo produziu alteraÃÃo significativa das preparaÃÃes mantidas sob tÃnus basal. Em preparaÃÃes de traqueia mantidas contraÃdas, a adiÃÃo de β-citronelol relaxou total e significativamente (p < 0,001; Two-Way ANOVA, seguido do teste Holm-Sidak) os anÃis de traqueia, com CI50 de 120,44 [73,29 - 197,91] ÂM para o K+ e 211,10 [114,13 â 390,46] ÂM para a ACh, e esse efeito nÃo foi alterado (p > 0,05; Teste de Mann-Whitney) apÃs o tratamento com Propranolol, L-NAME, TEA, Azul de Metileno, Ortovanadato de SÃdio, Capsazepina, Indometacina e A-967079. Em experimentos realizados com a remoÃÃo do Ca2+ e contendo EGTA, o β-citronelol inibiu a contraÃÃo mediante a entrada de Ca2+ preferencialmente em canais VOC, mas em altas concentraÃÃes, pÃde atuar tambÃm nos canais ROC e SOC, esse efeito foi mais pronunciado (p < 0,001; Two-Way ANOVA, seguido do teste Holm-Sidak) na contraÃÃo promovida pela adiÃÃo de Ba2+, demonstrando uma maior especificidade em atuar nos canais de Ca2+ operados por voltagem do tipo L. O β-citronelol tambÃm foi capaz de diminuir a contraÃÃo induzida pela estimulaÃÃo elÃtrica. Esses resultados demonstram que o β-citronelol caracteriza-se como uma substÃncia antiespasmÃdica e miorrelaxante do mÃsculo liso respiratÃrio, e esse efeito està parcialmente relacionado à sua capacidade de reduzir principalmente o acoplamento eletromecÃnico.
The β-citronellol is an alcoholic monoterpene of natural occurrence that is found in several essential oils, including the citronella oil (obtained from Cymbopogon winterianus). In general, it is widely used as insect repellent. Recently this molecule has been studied as antibacterial, antifungal, antispasmodic, hypotensive and vasorelaxant agent. We aimed to study the effects of β-citronellol on smooth muscle contractility of rat airways. The animals were divided in four groups namely Control, Sensitized, Challenged and Treated. Isometric recordings were obtained from isolated preparations from tracheal tissues cut as rings. Inhalation of β-citronellol (300 ÂM) before antigen (ovalbumin, OVA) challenge prevented development of tracheal hyperreactivity in response to K+ or ACh in tissues of OVA-sensitized animals. In vitro, the cumulative addition of β-citronellol (10 to 1000 ÂM) did not change basal tone in tracheal smooth muscle preparations. In tracheal rings pre-contracted with K+ or acetylcholine (ACh), the addition of β-citronellol fully relaxed (p < 0.001, Two-Way ANOVA, Holm-Sidak) tracheal rings with IC50 values of 120.44 [73.29 â 197.91] ÂM for K+ and 211.10 [114.13 - 390.46] ÂM for ACh. The relaxing effect of β-citronellol was not altered (p > 0.05, Mann-Whitney test) after treatment with propranolol, N (G)-nitro-L- arginine methyl ester (L-NAME), tetraethylammonium (TEA), methylene blue, sodium orthovanadate, capsazepine, indomethacin and A-967079. Experiments performed in Ca2+ depleted medium containing EGTA revealed that low concentrations of β-citronellol preferentially inhibited contractions induced by recruiting Ca2+ influx via voltage-operated channels (VOC), although at higher concentrations it could also inhibit either on contractions evocked with receptor-operated (ROC) or store-operated (SOC) pathways. Such effect was supported by the more pronounced inhibitory effects of β-citronellol (p < 0.001, Two-Way ANOVA, Holm-Sidak) against contractions promoted in tracheal tissues maintained in Ba2+-containing medium. β-Citronellol also decreased the contractions induced by electrical field stimulation. These results suggest that β-citronellol has antispasmodic and myorelaxant properties on airway smooth muscle, which could be partly related to its ability in inhibiting the electromechanical coupling.
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Vasconcelos, Thiago Brasileiro de. "Efeitos antiespasmódico e miorrelaxante do β-citronelol em músculo liso traqueal de ratos : potencial ação na hiperreatividade após desafio antigênico e elucidação do mecanismo de ação". reponame:Repositório Institucional da UFC, 2013. http://www.repositorio.ufc.br/handle/riufc/7923.
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VASCONCELOS, Thiago Brasileiro de. Efeitos antiespasmódico e miorrelaxante do ß-Citronelol em músculo liso traqueal de ratos : potencial ação na hiperreatividade após desafio antigênico e elucidação do mecanismo de ação. 2013. 119 f. Dissertação (Mestrado em Farmacologia) - Universidade Federal do Ceará, Fortaleza, 2013.Submitted by denise santos (denise.santos@ufc.br) on 2014-04-10T12:06:23Z No. of bitstreams: 1 2013_dis_tbvasconcelos.pdf: 2853478 bytes, checksum: fd84b6f4b086a9590b739082501a6d0a (MD5)
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The β-citronellol is an alcoholic monoterpene of natural occurrence that is found in several essential oils, including the citronella oil (obtained from Cymbopogon winterianus). In general, it is widely used as insect repellent. Recently this molecule has been studied as antibacterial, antifungal, antispasmodic, hypotensive and vasorelaxant agent. We aimed to study the effects of β-citronellol on smooth muscle contractility of rat airways. The animals were divided in four groups namely Control, Sensitized, Challenged and Treated. Isometric recordings were obtained from isolated preparations from tracheal tissues cut as rings. Inhalation of β-citronellol (300 µM) before antigen (ovalbumin, OVA) challenge prevented development of tracheal hyperreactivity in response to K+ or ACh in tissues of OVA-sensitized animals. In vitro, the cumulative addition of β-citronellol (10 to 1000 µM) did not change basal tone in tracheal smooth muscle preparations. In tracheal rings pre-contracted with K+ or acetylcholine (ACh), the addition of β-citronellol fully relaxed (p < 0.001, Two-Way ANOVA, Holm-Sidak) tracheal rings with IC50 values of 120.44 [73.29 – 197.91] µM for K+ and 211.10 [114.13 - 390.46] µM for ACh. The relaxing effect of β-citronellol was not altered (p > 0.05, Mann-Whitney test) after treatment with propranolol, N (G)-nitro-L- arginine methyl ester (L-NAME), tetraethylammonium (TEA), methylene blue, sodium orthovanadate, capsazepine, indomethacin and A-967079. Experiments performed in Ca2+ depleted medium containing EGTA revealed that low concentrations of β-citronellol preferentially inhibited contractions induced by recruiting Ca2+ influx via voltage-operated channels (VOC), although at higher concentrations it could also inhibit either on contractions evocked with receptor-operated (ROC) or store-operated (SOC) pathways. Such effect was supported by the more pronounced inhibitory effects of β-citronellol (p < 0.001, Two-Way ANOVA, Holm-Sidak) against contractions promoted in tracheal tissues maintained in Ba2+-containing medium. β-Citronellol also decreased the contractions induced by electrical field stimulation. These results suggest that β-citronellol has antispasmodic and myorelaxant properties on airway smooth muscle, which could be partly related to its ability in inhibiting the electromechanical coupling.
O β-citronelol é um álcool monoterpênico de ocorrência natural em vários óleos essenciais como o óleo de citronela (obtido de Cymbopogon winterianus), de ampla utilização popular por suas propriedades repelentes de insetos. Recentemente, a esta molécula tem sido atribuídas outras propriedades que envolvem atividade antibacteriana, antifúngica, antiespasmódica, hipotensora e vasorrelaxante. Sendo assim, objetivamos estudar suas possíveis ações no comportamento motor do músculo liso do sistema respiratório de ratos Wistar. Os animais considerados nesse estudo foram divididos em 04 grupos: controle, sensibilizado, desafiado e tratado, em seguida, registros isométricos, in vitro, foram obtidos a partir de anéis isolados de traqueia. A inalação de β-citronelol (300 µM) preveniu a hiperreatividade traqueal mediante a adição de K+ ou ACh em animais submetidos a um modelo de asma, no entanto, a adição cumulativa de β-citronelol (10 a 1000 µM), na cuba para órgãos isolados, não produziu alteração significativa das preparações mantidas sob tônus basal. Em preparações de traqueia mantidas contraídas, a adição de β-citronelol relaxou total e significativamente (p < 0,001; Two-Way ANOVA, seguido do teste Holm-Sidak) os anéis de traqueia, com CI50 de 120,44 [73,29 - 197,91] µM para o K+ e 211,10 [114,13 – 390,46] µM para a ACh, e esse efeito não foi alterado (p > 0,05; Teste de Mann-Whitney) após o tratamento com Propranolol, L-NAME, TEA, Azul de Metileno, Ortovanadato de Sódio, Capsazepina, Indometacina e A-967079. Em experimentos realizados com a remoção do Ca2+ e contendo EGTA, o β-citronelol inibiu a contração mediante a entrada de Ca2+ preferencialmente em canais VOC, mas em altas concentrações, pôde atuar também nos canais ROC e SOC, esse efeito foi mais pronunciado (p < 0,001; Two-Way ANOVA, seguido do teste Holm-Sidak) na contração promovida pela adição de Ba2+, demonstrando uma maior especificidade em atuar nos canais de Ca2+ operados por voltagem do tipo L. O β-citronelol também foi capaz de diminuir a contração induzida pela estimulação elétrica. Esses resultados demonstram que o β-citronelol caracteriza-se como uma substância antiespasmódica e miorrelaxante do músculo liso respiratório, e esse efeito está parcialmente relacionado à sua capacidade de reduzir principalmente o acoplamento eletromecânico.
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Trindade, Leonardo Antunes. "Atividade biológica do óleo essencial de Cymbopogon nardus e do fitoconstituinte citronelal sobre cepas de Candida envolvidas com infecções peri-implantares". Universidade Federal da Paraíba, 2014. http://tede.biblioteca.ufpb.br:8080/handle/tede/6662.
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Previous issue date: 2014-02-26Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
The study aimed to evaluate the biological activity of the essential oil of Cymbopogon nardus and citronellal phytochemical on Candida strains, checking the possible inhibition of adhesion to dental implants and cover screws. Initially, a screening was performed by the disk diffusion technique in Sabouraud Dextrose Agar (SDA) for the essential oils of Cinnamomum camphora (White Camphor), Melissa officinalis (Lemon Balm), Ocimum basilicum (Basil) and Cymbopogon nardus (citronella), as well as phytochemicals alpha pinene, citral, citronellal and carvacrol. After screening, the essential oil of C. nardus and citronellal were selected because they displayed significant antifungal activity. Then, essential oil was analyzed by Gas chromatography mass spectrometry (GC-MS). Subsequently, were determined MIC and MFC of essential oil and citronellal against 12 strains of Candida and tests of inhibition of adhesion to dental implants and cover screws, using the MIC of substances evaluated, followed by analysis on a Scanning Electron Microscope (SEM). Assays were performed in triplicate and chlorhexidine and nystatin were used as positive control. The data were analyzed on the software GraphPad Prism 4. Analysis of variance (ANOVA) with Tukey s post-test was carried out, with a confidence interval of 95%. The GC-MS analysis of the essential oil identified the major substance as citronellal terpenoid. The essential oil, citronellal, chlorhexidine and nystatin able to inhibit 100% of the strains was 64 μg/mL, 512 μg/mL, 64 μg/mL, 32 μg/mL, respectively. The essential oil inhibited the adhesion of C. albicans in the dental implants and cover screws (p <0.001). Citronellal only inhibited the growth of the strain in dental implants (p <0.001) with no significant results in the cover screws (p> 0.05) compared to the growth control. We conclude that the essential oil of C. nardus and citronellal have antifungal activity and are able to inhibit the in vitro adherence of C. abicans.
O estudo teve como objetivo avaliar a atividade biológica do óleo essencial de Cymbopogon nardus e do fitoconstituinte citronelal sobre cepas de Candida, verificando a possível inibição da aderência aos implantes dentários e cover screws. Inicialmente, foi realizado uma triagem por meio da técnica de disco-difusão em Agar Sabouraud Dextrose (ASD), para os óleos essenciais de Cinnamomum camphora (Cânfora Branca), Melissa officinalis (Erva Cidreira), Ocimum basilicum (Manjericão) e Cymbopogon nardus (Citronela), bem como dos fitoconstituintes alfa pineno, citral, citronelal e carvacrol. Após a triagem, o óleo essencial de C. nardus e o citronelal foram selecionados por terem apresentado expressiva atividade antifúngica. Em seguida, o óleo essencial foi analisado por cromatografia gasosa acoplada ao espectro de massa (GC-MS). Posteriormente, foram determinadas a CIM e CFM do óleo essencial e citronelal frente a 12 cepas de Candida e realizados testes de inibição da aderência aos implantes dentários e cover screws, utilizando-se a CIM das substâncias avaliadas, seguida de análise em Microscópio Eletrônico de Varredura (MEV). Os ensaios foram realizados em triplicata e a nistatina e clorexidina foram utilizadas como controle positivo. Os dados foram analisados no software GraphPad Prism 4. Foi realizada uma análise de variância (ANOVA) com pós-teste de Tukey ao nível de confiança de 95%. A análise por GC-MS do óleo essencial permitiu a identificação do terpenoide citronelal como substância majoritária. A CIM do óleo essencial, citronelal, clorexidina e nistatina capaz de inibir 100% das cepas foi 64 μg/mL; 512 μg/mL; 64 μg/mL; 32 μg/mL, respectivamente. O óleo essencial inibiu a aderência de C. albicans nos implantes dentários e cover screws (p<0,001). O citronelal inibiu apenas o crescimento da cepa nos implantes dentários (p<0,001), não apresentando resultados significantes nos cover screws (p>0,05) em relação ao controle de crescimento. Conclui-se que o óleo essencial de C. nardus e citronelal possuem atividade antifúngica e são capazes de inibir a aderência in vitro de C. abicans.
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Silva, Rebeca Almeida. "Sítntese e caracterização de peneiras moleculares do tipo MCM-41 modificadas com boro e gálio e sua aplicação na ciclização de (+)- citronelal". reponame:Repositório Institucional da UnB, 2011. http://repositorio.unb.br/handle/10482/8883.
Testo completoAbstract (sommario):
Dissertação Parcial (mestrado)—Universidade de Brasília, Instituto de Química, 2011.Submitted by Shayane Marques Zica (marquacizh@uol.com.br) on 2011-06-30T16:19:04Z No. of bitstreams: 1 2011_RebecaAlmeidaSilvaParcial.pdf: 1198554 bytes, checksum: df6b3f3dae7ee13725c5ff33ccd408db (MD5)
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A peneira molecular mesoporosa MCM-41 (Mobil Composition of Matter) apresenta arranjo hexagonal de poros com paredes de sílica amorfa, elevada capacidade de adsorção e elevada área superficial. Essas características tornam este material promissor para diversas aplicações em catálise e adsorção. Neste trabalho, as peneiras moleculares B-MCM-41 e Ga-MCM-41 foram sintetizadas na perspectiva de obter materiais com acidez superior à da Si-MCM-41. A caracterização dos sólidos sintetizados foi realizada por DRX, FTIR, adsorção de N2, análises térmicas, MAS RMN de 29Si, FRX/EDX e adsorção gasosa de piridina. As técnicas utilizadas permitiram inferir que a metodologia empregada para incorporação dos heteroelementos na estrutura não provocou colapso dos mesoporos. Todos os materiais apresentaram elevadas áreas superficiais e diâmetros de poro na faixa de 2 a 2,5 nm. A B-MCM-41 apresentou acidez semelhante à da Si-MCM-41, enquanto na Ga-MCM-41 foi observado o surgimento de sítios ácidos de Brønsted pela incorporação do metal na estrutura. Foram realizados testes catalíticos aplicando os materiais sintetizados à reação de ciclização intramolecular do aldeído (+)-citronelal, para obtenção do (–)-isopulegol. Os catalisadores Ga-MCM-41 proporcionaram resultados de conversão bastante superiores aos obtidos pelos materiais modificados com boro, devido à maior acidez gerada pela incorporação do gálio. Os testes foram realizados à temperatura ambiente, em condições brandas se comparadas às reportadas na literatura, e os materiais estudados proporcionaram seletividade em torno de 70% para o isômero desejado. O catalisador com razão Si/Ga = 25 apresentou os resultados mais promissores, atingindo 95% de conversão do (+)-citronelal após 2 h de reação. A reutilização desse catalisador causou diminuição da conversão, porém 90% da seletividade inicial para o (–)-isopulegol foi mantida, mesmo após 5 ciclos reacionais. _______________________________________________________________________________ ABSTRACT
The mesoporous molecular sieve MCM-41 (Mobil Composition of Matter) presents a hexagonal array of pores with amorphous silica walls, high adsorption capacity and high surface area. These properties result in a promisor material to several applications in catalysis and adsorption. In the present work, molecular sieves B-MCM-41 and Ga-MCM-41 was synthesized in order to obtain materials with higher acidity than Si-MCM-41. The materials were characterized by XRD, FTIR, N2 adsorption, thermal analysis, MAS 29Si NMR, XRF/EDX and gas phase pyridine adsorption. The characterization results showed that the methodology employed for incorporation of heteroelements into the framework did not cause collapse of mesopores. All materials presented high surface areas and pore diameters between 2 to 2,5 nm. B-MCM-41 exhibited similar acidity to Si-MCM-41, while Ga-MCM-41 exhibited Brønsted acid sites generated by the incorporation of gallium into the framework. Catalytic tests were performed using the modified materials in the intramolecular cyclization of (+)-citronellal. The results of conversion provided by Ga-MCM-41 catalysts were superior to the one obtained using B-MCM-41, because of the greater acidity achieved with the gallium incorporation. The tests were performed at room temperature, using mild conditions if compared with literature, and the studied materials provided about 70% of stereoselectivity for the desired isomer. The catalyst with Si/Ga molar ratio = 25 provided the best results, achieving 95% of conversion of (+)-citronellal after 2 h of reaction. The reuse of the catalyst caused decreasing on conversion, although 90% of stereoselectivity was preserved after 5 reaction cycles.
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Linares, Fuentes Thais Cleofé. "Estudio de catalizadores de Pd y Fe sobre soportes basados en Al2O3 para la transformación selectiva de citral hacia citronelal y derivados". Doctoral thesis, Universidad Nacional Mayor de San Marcos, 2016. https://hdl.handle.net/20.500.12672/8533.
Testo completoAbstract (sommario):
Publicación a texto completo no autorizada por el autorEstudia el sistema Pd y Fe sobre soportes basados en Al2O3 como catalizadores para la transformación selectiva de citral hacia citronelal y derivados. Los catalizadores se preparan por impregnación de las sales precursoras de los metales en una relación atómica Pd/Fe de 1 y con un porcentaje de 1,6% en peso. La calcinación de los precursores se lleva a cabo durante tres horas a 823 K. Se utilizan como métodos de caracterización: área superficial BET, adsorción y desorción de nitrógeno, quimisorción de monóxido de carbono, DRX, RTP y ATG. Los resultados muestran que los catalizadores Pd-Fe/Al2O3, Pd/Al2O3 y Pd/Fe2O3-Al2O3 son similares en términos de superficie BET, superficie metálica y son térmicamente estables. Los catalizadores óxidos metálicos se someten a un proceso de reducción a 573 K en una corriente de hidrógeno durante dos horas obteniéndose paladio metálico y hierro parcialmente reducido, por lo que la nomenclatura Pd-Fe corresponde al Pd-Fe2+. Las medidas de actividad se llevan a cabo a 353 K en un reactor semicontinuo: una solución de citral en 2-propanol y flujo continuo de Hidrógeno. Se toman muestras a intervalos de 5 min para monitorear la reacción, las cuales se analizan por cromatografía de gases en un equipo previamente calibrado para tal fin. Se evalúa la influencia del promotor Fe2+. Los resultados de la actividad muestran que el paladio es selectivo hacia citronelal. El Hierro en el estado oxidado Fe2+ orienta las reacciones hacia citronelal e dihidrocitronelal mientras que el Fe3+y el Mg2+ hacia citronelol.
Tesis
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Gaspar, Gabriel Vidal. "Avaliação do desenvolvimento de capim-citronela (cymbopogon winterianus) irrigado com três diferentes tipos de efluentes". reponame:Repositório Institucional da UFC, 2017. http://www.repositorio.ufc.br/handle/riufc/27361.
Testo completoAbstract (sommario):
GASPAR, G. V. Avaliação do desenvolvimento de capim-citronela (cymbopogon winterianus) irrigado com três diferentes tipos de efluentes. 2017. 79 f. Dissertação (Mestrado em Engenharia Civil)-Centro de Tecnologia, Programa de Pós-Graduação em Engenharia Civil: Saneamento Ambiental, Universidade Federal do Ceará, Fortaleza, 2017.Submitted by Edineuza Silva (edineuza@deha.ufc.br) on 2017-10-18T14:30:21Z No. of bitstreams: 1 2017_dis_gvgaspar.pdf: 3802736 bytes, checksum: 5381418ef1c6472cbba82ca2e67999cf (MD5)
Rejected by Marlene Sousa (mmarlene@ufc.br), reason: Prezado Gabriel: solicito que vc realizasse as alterações em sua dissertação para que a mesma fique de acordo com o template disponível em: http://www.biblioteca.ufc.br/educacao-de-usuarios/templates/ Gostaria de lembrar que o nada consta só poderá ser enviado após essas alterações serem realizadas. Só para esclarecimento, vou citar algumas dessas alterações: Na capa não se coloca a área de concentração, existe um local específico; retire a palavra dedicatória; Retire a caixa alta do título na ficha catalográfica; as referencias estão fora do padrão etc. Consulte a ferramenta para elaboração de referencias disponível em: http://www.biblioteca.ufc.br/ferramentas-de-pesquisa/ Aguardo envio do arquivo já com as alterações Att. Marlene Rocha mmarlene@ufc.br on 2017-10-20T16:46:11Z (GMT)
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Rejected by Marlene Sousa (mmarlene@ufc.br), reason: Prezado Gabriel: Sua dissertação não está no padrão da ABNT. Em e-mail anterior, eu citei apenas algumas alterações a serem realizadas, que vc já corrigiu, mas faltam outras. Voce deve seguir o template em relação ao uso de negrito, alinhamento das listas, redação das informações etc. Quanto a lista de referencias, já que vc usou o MORE vc não deve ter escolhido o tipo de material que vc está referenciando corretamente, pois nos artigos de revista o que fica em negrito é o nome da revista e não o titulo do artigo como vc colocou. Como tem muitas alterações a serem realizadas e como parece que vc está com duvidas, sugiro que vc venha aqui na biblioteca para eu lhe orientar. Fica a seu critério. Marlene on 2017-10-25T19:04:05Z (GMT)
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The use of domestic sewage treated for agricultural purposes has been gaining considerable ground in recent years. In addition to providing adequate use of natural resources, practice can improve soil characteristics and enhance agricultural production. However, the effluent is still a possible source of environmental impact, which can cause contamination by microorganisms and also salinize the soil, if there is a good design and operation of the reuse system. In this work, the effluent from an Anaerobic Upflow Reactor, RAFA, followed by an Aerated Submerged Filter, FSA, a Secondary Decanter, and a Contact Tank were used for the irrigation of citronella grass, Cymbopogon winterianus In the irrigation, the water used was supplied by the Water and Sewage Company of Ceará (Cagece), (TA), the treated effluent after the addition of chlorine (TB); and the effluent treated prior to addition of chlorine (TC). Each liquid was applied in seven pots, each pot with two plant seedlings, totalizing seven pots and fourteen plants for each type of effluent. The leaf chlorophyll index was analyzed; dry matter content; the content of inert matter; and some characteristics of the soils in the different vessels, after the period of 115 days. It was observed that the plants irrigated with treated effluents showed a better leaf development and a darker shade of green. In addition, the statistical analyzes of dry mass and inert mass production suggest a higher production of oils when irrigation with treated effluents was performed. The strategy of cultivating the species in irrigated pots with treated effluents can be positive for combating the spread of Dengue fever, Chikungunya fever and Zica, mosquito-related diseases, which are repelled by the plant's oils. Although a palliative measure, the dissemination of the practice can bring benefits to the population, combining the rational use of water resources with the cultivation of strategic plants.
O uso de esgotos domésticos tratados para fins agrícolas vem ganhando bastante espaço nos últimos anos. Além de proporcionar adequada utilização dos recursos naturais, a prática pode melhorar as características do solo e potencializar a produção agrícola. Entretanto, o efluente ainda é uma possível fonte de impacto ambiental, podendo causar contaminação por microrganismos e também salinizar o solo, caso não haja um bom dimensionamento e operação do sistema de reúso. Neste trabalho, utilizou-se o efluente de uma estação de tratamento do tipo Reator Anaeróbio de Fluxo Ascendente, RAFA, seguido por um Filtro Submerso Aerado, FSA, um Decantador Secundário, e um Tanque de Contato, para a rega de capim citronela, Cymbopogon winterianus. Na irrigação, foram utilizados: água de abastecimento fornecida pela Companhia de Água e Esgoto do Ceará (Cagece), (TA), o efluente tratado após a adição de cloro (TB); e o efluente tratado antes da adição de cloro (TC). Cada líquido foi aplicado em sete vasos, cada vaso com duas mudas do vegetal, totalizando-se sete vasos e quatorze plantas para cada tipo de efluente. Foram analisados: índice de clorofila nas folhas; teor de matéria seca; o teor de matéria inerte; e algumas características dos solos nos diferentes vasos, após o período de 115 dias. Percebeu-se que as plantas regadas com efluentes tratados apresentaram visualmente um melhor desenvolvimento foliar e tonalidade mais escura de verde. Além disso, as análises estatísticas de produção de massa seca e de massa inerte sugerem uma maior produção de óleos quando realizada irrigação com efluentes tratados. A estratégia de se cultivar a espécie em vasos irrigados com efluentes tratados pode ser positiva para o combate à disseminação da Dengue, da Febre Chikungunya e da Zica, doenças relacionadas a mosquitos, os quais são repelidos pelos óleos produzidos pela planta. Ainda que uma medida paliativa, a disseminação da prática pode trazer benefícios para a população, aliando o uso racional dos recursos hídricos ao cultivo de espécies vegetais estratégicas.
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Oliveira, Rafael Figueiredo de. "Evaluation of Proposed Natural Corrosion Inhibitors for X-52 Carbon Steel in Ethanol Media". University of Akron / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=akron1448385629.
Testo completo
30
Wang, Li-Chi, e 王莉琪. "Effects of Crown Gall Disease on Physiological Characteristics and Citronellal and Citronellol Concentrations of Eucalyptus Citriodora Seedlings". Thesis, 2004. http://ndltd.ncl.edu.tw/handle/54228527638648886889.
Testo completoAbstract (sommario):
碩士國立嘉義大學
森林暨自然資源研究所
94
The objective of this study was to investigate the effects of Agrobacterium tumefaciens on physiological characteristics, and concentrations of citronellal and citronellol of Eucalyptus citriodora seedlings. In this study, the differences of physiological characteristics, and essential oil contents of healthy and diseased seedlings of E. citriodora were analyzed. A. tumefaciens was isolated from crown gall tissues of E. citriodora seedlings. The A. tumefaciens isolates were then inoculated onto sterilized plantlets and calli of E. citriodora. The results revealed that the A. tumefaciens could attack E. citriodora seedlings and caused crown gall disease. The physiological characteristics of infected E. citriodora seedlings changed. The results showed that the non-infected seedlings had higher averaged total dry weight, leaf area, leaf water content, specific leaf area, and nitrogen content of roots. However, the infected seedlings had higher phosphorus, citronellal, and citronellol contents than the non-infected ones. Ultrastructural study with scanning electron microscope showed that there were significant differences among stomatal densities of infected and non-infected E. citriodora seedlings. In this study, sterilized seeds were aseptically cultured and inoculated with A. tumefaciens. The result showed that the in vitro plantlets developed crown gall after inoculation with A. tumefaciens. Further study revealed that the infected calli of E. citriodora had higher citronellal and citronellol contents. This study demonstrated that A. tumefaciens could stimulate the phosphorus, citronellal, and citronellol contents in tissues of E. citriodora.
31
Hung, Shan-Wei, e 洪善為. "Citronellol Induces the Necroptosis of Human Lung Cancer Cell via TNF-α pathway Through RIP3 Activation and Reactive Oxygen Species Accumulation". Thesis, 2015. http://ndltd.ncl.edu.tw/handle/57187008383771305840.
Testo completoAbstract (sommario):
碩士國立中興大學
生物化學研究所
103
Our previous studies showed that the essential oils of Pelargonium capitatum (EOPC) could induce the necroptosis of human non-small lung cancer cells. Citronellol, the major compound in EOPC, has anti-bacterial, anti-oxidant and anti- inflammatory effects. In this research, we would like to prove that citronellol may have noteworthy anticancer activity parallel to that of EOPC. Citronellol was used to treat lung cancers (A549, H1299, H23), breast cancer (BT-20), prostate cancer (PC3) and breast normal cell (MCF10A) to measure the cytotoxicity of citronellol with MTT assay. Among the six cell lines, human non-small lung cancer H1299 was shown the most susceptibility to citronellol (24/48/72 hr IC50=48 μg/mL, 39 μg/mL, 26 μg/mL). PI staining experiment with flow cytometry were applied to citronellol-treated H1299 cells.We found that citronellol could inhibit the cell growth and arrest the cell cycle at G1 phase. Further, citronellol could induce the necroptosis of H1299 cells by PI/Annexin-V double staining experiment. Due to necroptosis was resulted from ROS accumulation, H2DCF-DA fluorescent staining was applied to detect ROS products in H1299 cells after treated cells with citronellol and found that ROS concentration was accumulated in cancer cellswith time-dependent manner. The references indicated that when the necroptosis happened, TNF-α would be activated, down-stream RIP3 would complex with RIP1, and then ROS would accumulate quickly in cells. ROS accumulation caused DNA damage, followed by LMP and PARP over-activation andcellular energy depletion. Moreover, lysosome would be destroyed, and caused cathepsin B/D proteins to release into cytoplasm. If the necroptosis of signal pathway occurred, caspase would not be activated. Data of western blotting experiments showed that citronellol regulated the cell cycle of cancer cells by decreasing the protein levels of cyclin E, and promoted intracellular ROS accumulation. Citronellol could also increase the protein levels of TNF-α, RIP3, pro-PARP and cathepsin B/D in treated cells. However the protein levels of caspase-3 was not activated. We confirm that citronellol could induce the necroptosis of human lung cancer cell H1299 via TNF-α pathway through the RIP3 activation and ROS accumulation.
32
Eiasu, B. K. (Bahlebi Kibreab). "Influence of soil water management on plant growth, essential oil yield and oil composition of rose-scented geranium (Pelargonium spp.)". Thesis, 2009. http://hdl.handle.net/2263/28775.
Testo completoAbstract (sommario):
Introducing effective irrigation management in arid and semi-arid regions, like most areas of South Africa, is an indispensable way of maximising crop yield and enhancing productivity of scarce freshwater resources. Holistic improvements in agricultural water management could be realised through integrating the knowledge of crop-specific water requirements. In order to develop effective irrigation schedules for rose-scented geranium (Pelargonium capitatum x P. radens), greenhouse and field experiments were conducted at the Hatfield Experimental Farm of the University of Pretoria, Pretoria, South Africa, from 28 October 2004 to 2006. Results from 20, 40, 60 and 80% maximum allowable depletion (MAD) levels of the plant available soil water (ASW) indicated that plant roots extracted most of the soil water from the top 40 cm soil layer, independent of the treatment. Both essential oil yield and fresh herbage mass responded positively to high soil water content. Increasing the MAD level to 60% and higher resulted in a significant reduction in herbage mass and essential oil yields. An increase in the degree of water stress apparently increased the essential oil concentration (percentage oil on fresh herbage mass basis), but its contribution to total essential oil yield (kg/ha oil) was limited. There was no significant relationship between MAD level and essential oil composition. For water saving without a significant reduction in essential oil yield of rose-scented geranium, a MAD of 40% of ASW is proposed. Response of rose-scented geranium to a one-month irrigation withholding period in the second or third month of regrowth cycles showed that herbage mass and oil yield were positively related. Herbage yield was significantly reduced when the water stress period was imposed during the third or fourth month of regrowth. A remarkable essential oil yield loss was observed only when the plants were stressed during the fourth month of regrowth. Essential oil content (% oil on fresh herbage mass basis) was higher in stressed plants, especially when stressed late, but oil yield dropped due to lower herbage mass. The relationship between essential oil composition and irrigation treatments was not consistent. Water-use efficiency was not significantly affected by withholding irrigation in the second or in the third month of regrowth. With a marginal oil yield loss, about 330 to 460 m3 of water per hectare per regrowth cycle could be saved by withholding irrigation during the third month of regrowth. The overall results highlighted that in water-scarce regions withholding irrigation during either the second or the third month of regrowth in rose-scented geranium could save water that could be used by other sectors of society. In greenhouse pot experiments, rose-scented geranium was grown under different irrigation frequencies, in two growth media. Irrigation was withheld on 50% of the plants (in each plot) for the week prior to harvesting. Herbage and essential oil yields were better in the sandy clay soil than in silica sand. Essential oil content (% oil on fresh herbage mass basis) apparently increased with a decrease in irrigation frequency. Both herbage and total essential oil yields positively responded to frequent irrigation. A one-week stress period prior to harvesting significantly increased essential oil content and total essential oil yield. Hence, the highest essential oil yield was obtained from a combination of high irrigation frequency and a one-week irrigation-withholding period. In the irrigation frequency treatments, citronellol and citronellyl formate contents tended to increase with an increase in the stress level, but the reverse was true for geraniol and geranyl formate. Leaf physiological data were recorded during the terminal one-week water stress in the glasshouse pot trial. Upon rewatering, stomatal conductance (Gs) and transpiration rate (Rt) were significantly lower in the less often irrigated than in the more often irrigated treatments, while leaf water potential (yw) and relative water content (RWC) were the same for all plants, indicating that water stress had an after-effect on Gs and Rt. At the end of the stress period, Gs, Rt, yw and RWC were lower in the plants from the more often irrigated than from the less often irrigated treatments. Irrespective of irrigation treatment, one type of non-glandular and two types (different in shape and size) of glandular trichomes were observed. In water stressed-conditions, stomata and trichome densities increased, while the total number of stomata and trichomes per leaf appeared to remain more or less the same. Water stress conditions resulted in stomatal closure.Thesis (PhD)--University of Pretoria, 2009.
Plant Production and Soil Science
unrestricted
33
CHANG, HENRY HENG-JUI, e Henry HENG-JUI Chang. "Metal and EDDA Catalysis Reactions of Citral and Citronellal". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/cyub4w.
Testo completoAbstract (sommario):
碩士國立中正大學
化學暨生物化學研究所
107
Alkyne addition followed by Nicolas cyclization reaction with citronellal analogue has achieved successfully by using transition metal catalysis. Also, ethylenediamine diacetic acid was used to perform the cyclization between α,β-unsaturated aldehydes and phenols to construct polycyclic compounds with high yields in many cases.
34
Shieh, Dong-Lin, e 謝東陵. "Catalytic reaction of citronellal over zeolites and MCM-41 mesoporous molecular sieves". Thesis, 2001. http://ndltd.ncl.edu.tw/handle/82983752065771324301.
Testo completoAbstract (sommario):
碩士東海大學
化學系
89
Abstract Isopulegol (IPG) is an important intermediate for the synthesis of menthol, a raw material for the manufacture of pharmaceuticals, perfumery and flavors. The catalysts were characterized by the methods of XRD, BET surface area measurement, 27Al and 29Si MAS-NMR and TPD of ammonia. Increasing SiO2/Al2O3 mol ratio of MCM-41 catalysts results in the enhancement of both crystalinity and surface area with concomitant decrease of acid amount. Dealumination occurs after calcinations of Al-MCM-41. For zeolites, an increase of SiO2/Al2O3 mol ratio causes the decrease of acid amount and only small change in the surface area. The reaction of citronellal was performed at 220℃ and atmospheric pressure in a fixed-bed, integral-flow reactor by using zeolites HZSM-5, HY and Hβ as well as Si- and Al-MCM-41 molecular sieves.The effects of different catalysts with various SiO2/Al2O3 molar ratios on the catalytic results were investigated; all catalysts attain quite high activity and the isopulegol selectivity increases markedly with such ratios.Among all catalysts, Si-MCM-41 exhibits the best catalytic performance; the conversion and IPG yield are 91.9 and 58.6%, respectively, after at least 25 h process time. IPG was synthesized from citronellal at 40℃~60℃ and atmospheric pressure in a stirred batch reactor. The effect of solvents on the catalytic activity follows the decreasing order : toluene > ethyl acetate > cyclohexane > benzene. Therefore, polar solvents exhibit better catalytic performance. The catalytic activity decreases in the order of Al-MCM-41≒HY>Hβ>HZSM-5 for the reaction in toluene at 60℃ and 2 h reaction time. Both Al-MCM-41(50) and HY(80) exhibit the best IPG selectivity of 56%. Competitive first order reactions of citronellal product primary products of IPG, menthone and p-meth-4(8)-en-3-ol with corresponding activation energies 64.9, 67.5 and 89.3 kJ/mol.
35
LEE, CHIA-JUNG, e 李佳容. "Study of Citronella Extraction by Solvent and Steam Distillation". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/80501053431316716401.
Testo completoAbstract (sommario):
碩士國立聯合大學
化學工程學系碩士班
104
Citronella is a plant with a special aroma and is belong to the Gramineae Cymbopogon species. It has a good antibacterial effect. It also can prevent mosquito bites and is widely apply in expelling mosquitoes, refining essential oils, etc. Entire citronella contains volatile oil and chemical compositions like citronellal, citral, limonene, myrcene, etc. However, the compositions and contents in the essential oils of Cymbopogon plants can be different depending on the source and the species. The citronella is extracted by steam distillation in the industry. The essential oil has a pale yellow color. Solvent extraction is one of the simplest separation methods. In this study, we found the optimal condition of solvent extraction of the citronella leave and their stem. Solvents used for extraction experiment are ethanol, acetone, and deionized water. The optimal extraction condition of the citronella is found by testing at different extraction times, types of solvent, solvent concentrations, and temperatures. The best extraction condition is 1 gram of citronella leave extracting in 60 wt.% ethanol (50 g) at 50℃. After 72 hours of extraction, a high extraction yield is obtained. The mean total extraction yield is 17.39 wt.%. The extraction yield from the citronella leave is better than from the stem. A pale yellow oil with unique odor is obtained in direct steam distillation. After 4 hours of extraction, the mean yield is 1.53 wt.% from the leaf and is 0.46 wt.% from the stem. The major compositions of commercial and homemade essential oil are analyzed by Fourier transform infrared spectroscopy (FTIR) and gas chromatograph (GC). The citronellal in the citronella oil is determined by the relative volumetric method. The citronellal in citronella oil made in our lab is 36.34 wt.% from the leaf and is 35.17 wt.% from the stem. The citral is determined by specific quantitative colorimetric method. The handmade leaf oil contains 25.38 wt.% of citral and the stem oil contains 13.12 wt.% of citral.
36
Chiu, Yen-yi, e 邱嬿誼. "The Development of Citronella Industry ─ A Case of Maioli Da-hu". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/47187708354166575085.
Testo completoAbstract (sommario):
碩士國立聯合大學
客家語言與傳播研究所
99
The study of citronella industry is discussed from the points of industry development, ethnic division of labor, market transaction, management transformation, and it was conducted through literature review and in-depth interview. The study interprets the context of changes in citronella industry from diffusion of innovations, ethnic division of labor as well as Hakka people’s economic behavior in citronella industry from embeddness and market theory, and finally the management of this transforming industry. The laboring in citronella industry can be divided into family production or factory manufactures. The ethnic division of labor shows different condition. For family production, Hakka people hire Holo workers in the mountain area and change workers with each other in the plain area. For factory manufacture, the manager and workers are all Hakka people . The way of transaction in citronella industry displays the characteristics of Hakkaness economic behavior. There are three ways to sell citronella oil in the place of production: one is cash in hand, another is deposit oil, and the other is offset debt by giving oil. Contract in citronella oil transaction is not needed. The farmers sell citronella oil by depositing oil; the middle sellers sell oil when it is at higher price, which was bought in advanced. If it’s a huge transaction and the middele sellers can not know the price tendency, the transaction may end up in bankrupt. The citronella oil transaction is an economic behavior with high risk. Thus, Hakka people are not conservative and traditional when they behave in citronella industry transaction. The unique way of transaction of citronella oil led to chaos, so the government intervene in the market. When the marketing is stable, the government reward citronella industry by its policy; when unstable, the government try to balance the price by subsidizing farmers and sellers. During 1950’s and 1960s’, citronella oil from Taiwan played an important role in the international market, sharing 70 percentage of total supply. The government tried to stabilize the market, which the farmers didn’t realize. In 1968, citronella oil was replaced by artificial flavors. Nowadays the management of citronella industry has transformed , adds creation into the old industrial heritage as well as put the Hakka culture symbol into product. The manager try to transform as well as keep the citronella industry develop through rebuliding the citronella cottage, transmitting story, guided tours, and leting customers experience how to make oil.
37
Means, Guy H. "A marine-influenced siliciclastic unit (citronelle formation) in Western Panhandle Florida". 2009. http://etd.lib.fsu.edu/theses/available/etd-04122009-101055.
Testo completoAbstract (sommario):
Thesis (M.S.)--Florida State University, 2009.Advisor: Sherwood W. Wise, Florida State University, College of Arts and Sciences, Dept. of Geological Sciences. Title and description from dissertation home page (viewed July 6, 2009). Document formatted into pages; contains x, 134 pages. Includes bibliographical references.
38
ming, Yang ching, e 楊檾銘. "Proteomic Analysis of the Antibacterial Effects of Linalool and Citronellal in the Curdlan Packing Films on Staphylococcus aureus". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/38653601390660060537.
Testo completoAbstract (sommario):
碩士實踐大學
食品營養與保健生技學系碩士班
99
The aim of this study was to investigate antibacterial effect of linalool and citronellal on Staphylococcus aureus in curdlan gum edible film. Using turbidity method to evaluate microbial growth and flow cytometry to observed bacterial cell’s damage and death. Furthermore we analyzed the fatty acid composition of S. aureus cell treated with linalool and citronellal, respectively, by gas chromatography-mass-mass (GC-MS-MS).The result data showed that S. aureus cells were really damaged, and we could observe its fatty acid C16:0 and C18:1 increased from 1 to 1.5 folds. Moreover, antibacterial test of curdlan gum edible film containing with linalool and citronellal on S. aurous was evaluated by inhibition zone method. The results showed that the growth of S. aureus was inhibited by the different concentration of the two chemicals, their inhibition zones reach to 31 and 38 mm, respectively. The moisture, transparency, water solubility, and penetration test of the edible film were determined by physical tests. In the resulting data, we observed the increased penetration as the increase in concentrations of the two chemicals. Finally, we used proteomic approach to compare the modified expression proteins after exposure of S. aureus with different concentrations of linalool and citronellal. In the linalool and citronellal both treatments, the protein expressions of S. aureus were down-regulated. We observed that those down-regulated proteins were associated with metabolisms of carbohydrates, proteins, lipids, and redox reaction. It may be suggested that S. aureus cells were stimulated with protection mechanisms in cell metabolism in response to linalool and citronellal treatments. The two chemicals may induce the increased permeability on cells by changing the structures and components of lipids and proteins in bacteria membranes. Additionally, their DNA and RNA replication, and protein synthesis were also affected. This study revealed that linalool and citronellal are with a good antibacterial activity and they may be used on curdlan gum edible antimicrobial film in application of food packaging.
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Waliwitiya, Ranil. "Toxicities of thymol, citronellal, eugenol and rosemary oil to control Agriotes obscurus (Coleoptera: Elateridae) in laboratory and greehouse bioassays". Thesis, 2005. http://hdl.handle.net/2429/16757.
Testo completoAbstract (sommario):
Toxicities were determined for four naturally occurring monoterpenoid essential
oils on late instar larvae of Agriotes obscurus in laboratory and greenhouse bioassays.
Both contact and fumigant toxicities were determined for thymol, citronellal, eugenol and
rosemary oil. Thymol had the greatest contact toxicity (LD₅₀=196.0 μg/larva) while
citronellal and eugenol were significantly less toxic (LD₅=404.9 μg/larva and 516.5
μg/larva, respectively). Rosemary oil did not show any significant contact toxicity, at the
highest dose tested, 1600 μg/larva. In fumigant bioassays, citronellal was the most toxic
to wireworm larvae (LD₅=6.3 μg/cm ) followed by rosemary oil (LD₅=15.7 μg/cm ),
thymol (LD₅=16.9 μg/cm³), and eugenol (LD₅=20.8 μg/cm³). Phytotoxicities were also
evaluated based on corn seed germination and seedling development. In laboratory
bioassays, thymol and citronellal significantly inhibited seed germination and
development while rosemary oil had only minimal phytotoxic effects.
Based on these laboratory results, four treatments were selected for repellency
trials under greenhouse conditions. Citronellal (800 pg/seed), thymol (400 μg/seed),
rosemary oil (1600 μg/seed) and eugenol (1600 pg/seed) were evaluated for their ability
to protect corn seeds from Agriotes obscurus feeding damage. In the bioassay, wireworm
health, seed germination, seed damage, and seedling height were evaluated. Rosemary oil
treated seeds produced the highest number of distressed wireworms (56%, Odds Ratio =
2.64) compared to all other treatments while not creating any phytotoxic effects. Seeds
treated with thymol were the least damaged (90.7% undamaged, Odds Ratio = 0.153)
compared to the control while thymol and citronellal retarded seedling height compared
to the control. Eugenol produced the lowest seed germination (25.3% germination) while
citronellal, rosemary oil and thymol had no negative impact on seed germination.Land and Food Systems, Faculty of
Graduate
40
GILLIS, JAMES. "PRODUCTION OF MEDIUM-CHAIN-LENGTH POLY(3-HYDROXYALKANOATES) USING PSEUDOMONAS CITRONELLOLIS DSM50332 AND P. PUTIDA KT2440 IN CONTINUOUS REACTOR SYSTEMS". Thesis, 2011. http://hdl.handle.net/1974/6915.
Testo completoAbstract (sommario):
In vivo production of medium-chain-length poly(3-hydroxyalkanoates) (MCL-PHA) containing a side chain carboxyl group from azelaic acid (AzA), a nine-carbon α,ω-dicarboxylic acid, was investigated using Pseudomonas citronellolis DSM 50332 in a phosphate (P)-limited chemostat. Co-feeding with nonanoic acid (NA) and inhibition of β-oxidation with acrylic acid (AA) were strategies that were used to stimulate the incorporation of carboxylated monomers, but both were unsuccessful. P. citronellolis DSM50332 was capable of growing on AzA as a sole source of carbon and energy, indicating that enzymes in β-oxidation utilized AzA and its derivatives. However, the MCL-PHA produced from AzA comprised 3-hydroxyoctanoate (C8) and 3-hydroxydecanoate (C10) monomers, which was consistent with precursor supplied via the de novo fatty acid biosynthesis pathway. This evidence suggests that one or more of 3-ketoacyl-CoA reductase (FabG), enoyl-CoA hydratase (PhaJ) and PHA synthase (PhaC) of this organism do not have the low specificity required to utilize a carboxylated substrate. Future work involving mutations may broaden the substrate specificity of these key enzymes to overcome this obstacle.
Two-stage high-cell density carbon (C)-limited chemostat cultivation of P. putida KT2440 was examined for MCL-PHA production from nonanoic acid (NA) at high intracellular polymer content and volumetric productivity. Growth conditions stimulating good PHA production were first established in single-stage chemostat, which yielded 63.1 wt% PHA containing 90 mol% C9 units and a productivity of 1.52 g L-1h-1 at a dilution rate of 0.30 h-1. This productivity was higher than any value reported in literature for continuous MCL-PHA production systems and comparable to the upper range of fed-batch results. Two-stage production yielded promising results, notably the increase in polymer content from the first to second stage. However, complications involving foaming and an unexplained decline in PHA content adversely affected system performance. The best PHA content and overall productivity were 58.5 wt% and 0.76 g L-1h-1, respectively. Nonetheless, the results demonstrate the potential to achieve high PHA content
without the need for pure oxygen at high dilution rates, warranting further investigation focusing on the
optimization of growth conditions.Thesis (Master, Chemical Engineering) -- Queen's University, 2011-12-19 15:48:21.808