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Argemí-Armengol, Immaculada, Daniel Villalba, Marc Tor, Cristina Pérez-Santaescolástica, Laura Purriños, José Manuel Lorenzo, and Javier Álvarez-Rodríguez. "The extent to which genetics and lean grade affect fatty acid profiles and volatile compounds in organic pork." PeerJ 7 (July 17, 2019): e7322. http://dx.doi.org/10.7717/peerj.7322.
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Niche production is intended to produce premium pork, but several husbandry factors may affect the meat fatty acid composition and aroma. Fatty acid profile (by GC-FID) of raw meat and volatile compounds (by SPME-GC–MS) of cooked meat were analysed in loin samples from two pig genetic types-75% Duroc (Du) and 50% Pietrain (Pi) rossbreds that were slaughtered at different weights (90 kg and 105 kg, respectively) to achieve similar target carcass fatness, and the outcome carcasses were balanced for lean grade groups (<60% or ≥60% lean) within genotypes. Genetic type did not affect fatty acids (FA) profile of meat. The leaner meat had lower C12:0 and C20:3n − 3, lower saturated fatty acids (SFA) and higher MUFA/SFA ratio content than the fattier meat. Short-chain alcohols were lower in Pietrain and in leaner pork compared to the samples from Duroc crossbreds and fattier pork. A greater amount of hexane,2,4,4-trimethyl (an aliphatic hydrocarbon) but lower carbon disulphide (sulphur compound) content was detected in pork from leaner compared to fattier pork. Higher aromatics hydrocarbons were exclusively associated with Duroc crossbreds, and lower aliphatic hydrocarbons with pigs classified as fattier. Most of the volatile compounds detected in the present study came from lipid oxidation.
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Rethemeyer, Janet, Christiane Kramer, Gerd Gleixner, Guido L. B. Wiesenberg, Lorenz Schwark, Nils Andersen, Marie-J. Nadeau, and Pieter M. Grootes. "Complexity of Soil Organic Matter: AMS 14C Analysis of Soil Lipid Fractions and Individual Compounds." Radiocarbon 46, no. 1 (2004): 465–73. http://dx.doi.org/10.1017/s0033822200039771.
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Radiocarbon measurements of different lipid fractions and individual compounds, isolated from soil samples collected on 2 different agricultural long-term study sites, located in the rural area of Rotthalmünster (Germany) and in the city of Halle/Saale (Germany), were analyzed to obtain information about sources and the stability of soil organic matter (SOM). Different lipid compound classes were isolated by automated solvent extraction and subsequent medium-pressure liquid chromatography. Generally, 14C contents of lipid compound classes from topsoil samples of maize plots at Rotthalmünster are close to the modern atmospheric 14C content. Lower 14C values of aliphatic and aromatic hydrocarbons isolated from neutral lipids suggest a contribution of old carbon to these fractions. In contrast, 14C values of bulk soil (52 pMC) as well as isolated lipid classes from Halle are highly depleted. This can be attributed to a significant contribution of fossil carbon at this site. Extremely low 14C contents of aromatic (7 pMC) and aliphatic hydrocarbons (19 pMC) reflect the admixture of fossil hydrocarbons at the Halle site. Individual phospholipid fatty acids (PLFA), which are used as a proxy for viable microbial biomass, were isolated by preparative capillary gas chromatography (PCGC) from topsoils at Rotthalmünster and Halle. PLFA 14C values are close to atmospheric 14C values and, thus, indicate a clear microbial preference for relatively young SOM. At Rotthalmünster, the 14C concentration of short-chain unsaturated PLFAs is not significantly different from that of the atmosphere, while the saturated PLFAs show a contribution of sub-recent SOM extending over the last decades. At Halle, up to 14% fossil carbon is incorporated in PLFAs n-C17:0 and cy-C18:0, which suggests the use of fossil carbon by soil microorganisms. Moreover, it can be concluded that the 14C age of soil carbon is not indicative of its stability.
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Bano, Jafra, Swapna Santra, and Ekta Menghani. "EVALUATION AND CHARACTERIZATION OF BIOACTIVE COMPOUND OF HAMELIA PATENS PLANT WITH THE GC-MS SPECTROSCOPY." Asian Journal of Pharmaceutical and Clinical Research 11, no. 11 (November 7, 2018): 232. http://dx.doi.org/10.22159/ajpcr.2018.v11i11.27557.
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Objective: The aim of this study is to evaluate the bioactive compound present in the leaves, root, flower, and stem by gas chromatography (GC) analysis. Novel drugs are isolated from plants against human diseases.Methods: The plant parts (leaves, stem, flower, and root) were collected, washed, shade dried, and powdered, and the methanol extracts of all plant parts were prepared by Soxhlet reflux method. The methanolic extracts were analyzed for the identification of phytochemical compounds present in the Hamelia patens plant parts using GC-mass spectrometry (MS) matched by the National Institute of Standards And Technology-11 library and Willey 8 library.Results: The bioactive fraction on GC-MS analysis revealed a chromatogram showing highest peaks. Methanol extracts of H. patens leaf are found to possess a wide range of saturated and unsaturated aliphatic hydrocarbons and their isomers such as 2,3-dihydro-3,5-dihydroxy-6-methyl- 4H-pyran (1.77%), 1,3-propanediol, 2-ethyl-2-(hydroxymethyl) (3.06%), mome inositol (18.22%), pentadecanoic acid (1.66%), and squalene (11.47%). GC-MS analysis revealed chromatogram, showing that the highest peaks of H. patens stem are methyl salicylate (3.41%), 2-amino-9-(3,4- dihydroxy-5- hydroxymethyl) (9.53%), mome inositol (63.73%), and squalene (1.07%).Conclusion: Isolation of such bioactives and their use as therapeutic target is the prime motto of our research to isolate novel bioactive that can used as potential therapeutic agents.
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Lodowska, Jolanta, Daniel Wolny, Sławomir Kurkiewicz, and Ludmiła Węglarz. "The Pyrolytic Profile of Lyophilized and Deep-Frozen Compact Part of the Human Bone." Scientific World Journal 2012 (2012): 1–7. http://dx.doi.org/10.1100/2012/162406.
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Background. Bone grafts are used in the treatment of nonunion of fractures, bone tumors and in arthroplasty. Tissues preserved by lyophilization or deep freezing are used as implants nowadays. Lyophilized grafts are utilized in the therapy of birth defects and bone benign tumors, while deep-frozen ones are applied in orthopedics. The aim of the study was to compare the pyrolytic pattern, as an indirect means of the analysis of organic composition of deep-frozen and lyophilized compact part of the human bone.Methods. Samples of preserved bone tissue were subjected to thermolysis and tetrahydroammonium-hydroxide- (TMAH-) associated thermochemolysis coupled with gas chromatography and mass spectrometry (Py-GC/MS).Results. Derivatives of benzene, pyridine, pyrrole, phenol, sulfur compounds, nitriles, saturated and unsaturated aliphatic hydrocarbons, and fatty acids (C12–C20) were identified in the pyrolytic pattern. The pyrolyzates were the most abundant in derivatives of pyrrole and nitriles originated from proteins. The predominant product in pyrolytic pattern of the investigated bone was pyrrolo[1,2-α]piperazine-3,6-dione derived from collagen. The content of this compound significantly differentiated the lyophilized graft from the deep-frozen one. Oleic and palmitic acid were predominant among fatty acids of the investigated samples. The deep-frozen implants were characterized by higher percentage of long-chain fatty acids than lyophilized grafts.
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Yanchevskaya, E. Yu, and Olga A. Mesnyankina. "MICROCIRCULATION OF THE SKIN IN WORKERS OF GAS-PROCESSING PLANT." Russian Journal of Skin and Venereal Diseases 20, no. 4 (September 15, 2017): 234–37. http://dx.doi.org/10.18821/1560-9588-2017-20-4-234-237.
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Microcirculatory disorders play an important role in the pathogenesis of dermatoses, including those caused by the influence of adverse factors of production environment. 158 men from the Astrakhan gas processing plant (AGPS) aged from 28 to 59 years (40.23 ± 0.49 years) and 77 healthy volunteers, resident in the city of Astrakhan in age from 25 to 55 years (38,18 ± 0,99 years) were examined. Depending on the technological stage of processing of reservoir gas workers AGPS had contact with various harmful and dangerous factors, among which were the formation of gas, elementary sulfur, hydrocarbons, saturated and unsaturated aliphatic compound, nitrogen oxides, etc. In more than 90% of cases in the skin of workers AGPS serious violations of blood perfusion in small vessels, and in the surface areas more often than in the deep, while marked asymmetry of cutaneous microcirculation were revealed. Laser Doppler flowmetry can be recommended as a noninvasive method of monitoring the condition of microcirculation and early diagnosis of premorbid changes in the skin of workers of the gas processing plant exposed to adverse factors of production environment.
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Brahmbhatt, Harshad, Maja Molnar, Valentina Pavić, and Vesna Rastija. "Synthesis, Characterization, Antibacterial and Antioxidant Potency of NSubstituted- 2-Sulfanylidene-1,3-Thiazolidin-4-one Derivatives and QSAR Study." Medicinal Chemistry 15, no. 8 (November 18, 2019): 840–49. http://dx.doi.org/10.2174/1573406415666181205163052.
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Background: Rhodanine is known for its potential and important role in the medicinal chemistry since its derivatives exhibit a wide range of pharmacological activities such as antibacterial, antifungal, antidiabetic, antitubercular, anti-HIV, antiparasitic, antioxidant, anticancer, antiproliferative and anthelmintic agents. Objectives: Since N-substituted rhodanine synthons are rarely commercially available, it is desirable to develop a straightforward synthetic approach for the synthesis of these key building blocks. The objective was to synthesize a series of rhodanine derivatives and to investigate their antimicrobial and antioxidant activity. Also, in order to obtain an insight into their structure-activity relationship, QSAR studies on the antioxidant activity were performed. Methods: 1H and 13C FTNMR spectra were recorded on Bruker Avance 600 MHz NMR Spectrometer, mass analysis was carried out on ESI+ mode by LC-MS/MS API 2000. 2,2-Diphenyl-1- picrylhydrazyl radical scavenging activity (% DPPH) was determined in dimethylsulfoxide (DMSO) as a solvent. The antibacterial activity was assessed against Bacillus subtilis, Staphylococcus aureus (Gram positive) and Escherichia coli, Pseudomonas aeruginosa (Gram negative) bacteria in terms of the minimum inhibitory concentrations (MICs) by a modified broth microdilution method. Results: A series of N-substituted-2-sulfanylidene-1,3-thiazolidin-4-ones were synthesized and characterized by 1H NMR, 13C NMR, FTIR, GC MS, LCMS/MS and C,H,N,S elemental analysis. Most of the synthesized compounds showed moderate to excellent antibacterial activity (MIC values from 125 μg/ml to 15.62 μg/mL) and DPPH scavenging activity (from 3.60% to 94.40%). Compound 2-thioxo-3- (4-(trifluoromethyl)-phenyl)thiazolidin-4-one showed the most potent activity against Escherichia coli (3.125 μg/mL), equivalent to antibiotic Amikacin sulphate and against Staphylococcus aureus (0.097 μg/ml), 100 times superior then antibiotic Amikacin sulphate. It has also shown a potent antioxidant activity (95% DPPH scavenging). Two best QSAR models, obtained by GETAWAY descriptor R7p+, Balabans molecular connectivity topological index and Narumi harmonic topological index (HNar), suggest that the enhanced antioxidant activity is related to the presence of pairs of atoms higher polarizability at the topological distance 7, substituted benzene ring and longer saturated aliphatic chain in N-substituents. Conclusion: A series of novel N-substituted-2-thioxothiazolidin-4-one derivatives were designed, synthesized, characterized and evaluated for their antibacterial and antioxidant activity in vitro. Majority of the compounds showed excellent antibacterial activity compared to ampicillin and few of them have an excellent activity as compared to Chloramphenicol standard antibacterial drug. The QSAR study has clarified the importance of presenting a pairs of atoms higher polarizability, such as Cl and S at the specific distance, as well as the substituted benzene ring and a long saturated aliphatic chain in N-substituents for the enhanced antioxidant activity of 2-sulfanylidene-1,3- thiazolidin-4-one derivatives.
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Farmani, Zahra, and Wolfgang Schrader. "A Detailed Look at the Saturate Fractions of Different Crude Oils Using Direct Analysis by Ultrahigh Resolution Mass Spectrometry (UHRMS)." Energies 12, no. 18 (September 7, 2019): 3455. http://dx.doi.org/10.3390/en12183455.
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SARA (Saturates, Aromatics, Resins, Asphaltenes) fractionation is a common simplification technique used for decades in petrochemical analysis. A large number of studies are dealing with the different fractions, but overall, the saturate fraction is strongly neglected. Of the very few available studies on the saturates fraction, almost all have been performed using gas chromatographic (GC) techniques. This discriminates the results of the saturate fraction especially since non-volatile, high molecular weight and polar constituents are mostly excluded. Here, for the first time, saturate fractions of different crude oils from different origins are analyzed using direct infusion ultrahigh resolution mass spectrometry (UHRMS), to study the compositions on a molecular level. Electrospray (ESI), atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI) are used in positive mode. The observed results show the presence of different heteroatom containing classes, with different chemical identities (i.e., presence of thiophenes, mercaptans and cyclic-sulfides in case of S-containing compounds). These results show the high affinity of some specific compounds towards different ionization techniques. Finally, the saturate fraction is shown to include much more than only volatile, saturated and aliphatic compounds. The detected compounds in this fraction present a very wide variety, not only in terms of their carbon atoms per molecule and their aromaticity, but also with regard to their functional groups and structural arrangements.
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Menéndez, R., R. Más, A. M. Amor, N. Ledón, J. Pérez, R. M. González, I. Rodeiro, M. Zayas, and S. Jiménez. "Inhibition of rat lipoprotein lipid peroxidation by the oral administration of D003, a mixture of very long-chain saturated fatty acids." Canadian Journal of Physiology and Pharmacology 80, no. 1 (January 1, 2002): 13–21. http://dx.doi.org/10.1139/y01-088.
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Previous results have demonstrated that policosanol, a mixture of aliphatic primary alcohols isolated and purified from sugar cane wax, whose main component is octacosanol, inhibited lipid peroxidation in experimental models and human beings. D003 is a defined mixture of very long-chain saturated fatty acids, also isolated and purified from sugar cane wax, whose main component is octacosanoic acid followed by traicontanoic, dotriacontanoic, and tetracontanoic acids. Since very long-chain fatty acids are structurally related to their corresponding alcohols, we investigated the effect of oral treatment with D003 (0.5, 5, 50, and 100 mg/kg) over 4 weeks in reducing the susceptibility of rat lipoprotein to oxidative modification. The combined rat lipoprotein fraction VLDL + LDL was subjected to several oxidation systems, including those containing metal ions (CuSO4), those having the capacity to generate free radicals 2,2-azobis-2-amidinopropane hydrochloride (AAPH), and a more physiological system (resident macrophages). D003 (5, 50, and 100 mg/kg) significantly inhibited copper-mediated conjugated-diene generation in a concentration-dependent manner. D003 increased lag phase by 53.1, 115.3, and 119.3%, respectively, and decreased the rate of conjugate-diene generation by 16.6, 21.5, and 19.6%, respectively. D003 also inhibited azo-compound initiated and macrophage-mediated lipid peroxidation as judged by the significant decrease in thiobarbituric acid reactive substance (TBARS) generation. In all the systems the maximum effect was attained at 50 mg/kg. There was also a parallel attenuation in the reduction of lysine amino groups and a significant reduction of carbonyl content after oxidation of lipoprotein samples. Taken together, the present results indicate that oral administration of D003 protects lipoprotein fractions against lipid peroxidation in the lipid as well in the protein moiety.Key words: D003, very long-chain saturated fatty acids, lipoprotein lipid peroxidation.
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Miyazato, Hironari. "Identification of the Compounds Responsible for the Sweat-Like Odor in Hop (Humulus lupulus L.) Volatile Oil." Journal of Food Research 2, no. 5 (August 7, 2013): 34. http://dx.doi.org/10.5539/jfr.v2n5p34.
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<p>The aroma of hop volatile oil contains a sweat-like odor. We studied the odorous volatile compounds responsible for the sweat-like odor in the volatile oil extracted from Hallertau Perle hop (<em>Humulus</em><em> </em><em>lupulus</em><em> </em>L.) pellets. The combined use of gas chromatography-mass spectrometry/olfactometry (GC-MS/O), aroma extract dilution analysis (AEDA) by GC-MS/O (an odor dilution technique), and heart-cut multidimensional GC-MS (heart-cut MDGC-MS) equipped with the polar (1D) and apolar (2D) capillary columns revealed seven sweat-like odor producing compounds: methyl-branched saturated and unsaturated aliphatic acids, such as 3-methylbutanoic acid (sweaty/rancid/cheese-like), 2-methylbutanoic acid (sweaty/rancid/cheese-like), 4-methyl-3-pentenoic acid (sweaty/urine-like/malodor in laundry), and (<em>E</em>)-4-methyl-3-hexenoic acid (sweaty/urine-like/malodor in laundry), as well as others, such as an unknown compound (sweaty), methyl (<em>E</em>)-4-methyl-3-hexenoate (sweaty/malodor in laundry/fruity), and <em>S</em>-methyl (<em>E</em>)-4-methyl-3-hexenethioate (sweaty/rubber). The reference substances were synthesized stereo selectively using for the identification procedures. In this study, (<em>E</em>)-4-methyl-3-hexenoic acid, methyl (<em>E</em>)-4-methyl-3-hexenoate, and <em>S</em>-methyl (<em>E</em>)-4-methyl-3-hexenethioate were identified for the first time in hop volatile oil.</p>
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Tanaka, Takeshi. "Polishing Performance of Electro-Rheological Fluid of Polymerized Liquid Crystal Contained Abrasive Grit." Key Engineering Materials 404 (January 2009): 123–30. http://dx.doi.org/10.4028/www.scientific.net/kem.404.123.
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In this study, we proposed an electro-rheological fluid-aided polisher (ERAP) using one-sided, patterned electrodes. The characteristics of ER fluid and ER fluid containing abrasive grit were investigated. The polishing performances of ER fluids with and without abrasive grit employing ERAP were verified and the following conclusions were obtained. Decreases in viscosity and in the ER effect were observed when highly polymerized liquid crystal (hereafter referred to as HPLC) was diluted with silicon oil. However, the mixing of abrasive grit increases the ER effect, but the ER effect of ER fluid containing abrasive grit decreased when mixed with abrasive grit. The viscosity decreased with increases in aliphatic saturated cyclic hydrocarbon oil (hereafter referred to as NCDM) mixed in highly polymerized compound (one kind of HPLC). The larger the positive dielectric anisotropy, the larger the ER effect in low-polymerized liquid crystal (hereafter referred to as LPLC). The smaller the grit size, the weaker the ER effect. When polished with HPLC, the polished surface was rough due to the large viscosity of an HPLC:silicon oil ratio of 4:14 mixed with #2000WA. However, the smallest surface roughness was attained at 0.5kV/mm for an HPLC:silicon oil ratio of 1:17 mixed with #2000WA. The surface quality was improved at an HPLC: silicon oil ratio of 1:17 mixed with #3000WA. When polished with LPLC, the surface roughness was improved by the increased ER effect when LPLC having a positive dielectric anisotropy was used. However, the surface roughness showed no change when LPLC with a negative dielectric anisotropy was used, due to its small ER effect.
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Zieliński, Marek, Ewa Twardowska, and Małgorzata Kucharska. "Pentane-1-ol and its isomers. Determination in workplace air with GC with Flame Ionization Detector (GC-FID)." Podstawy i Metody Oceny Środowiska Pracy 35, no. 1(99) (March 25, 2019): 75–88. http://dx.doi.org/10.5604/01.3001.0013.0807.
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Amyl alcohol (pentan-1-ol) – C5H12O or C5H11OH – is an organic chemical compound from the group of saturated monohydric aliphatic alcohols. There are 8 known isomers of pentanol: pentan-1-ol (CAS:71-41-0), pentan-2-ol (CAS: 6032-29-7), pentan-3-ol (CAS: 584-02-1), 2-metylobutan-1-ol (CAS: 137-32-6), 3-metylobutan-1-ol (CAS: 123-51-3), 2-metylobutan-2-ol (CAS: 75-85-4), 3-metylobutan-2-ol (CAS: 598-75-4) i 2,2-dimetylopropan-1-ol (CAS: 75-84-3). All of them are commonly referred to as amyl alcohols. Pentanol isomers exhibit chemical properties characteristic of aliphatic alcohols, they are obtained by hydration of pentene isomers, hydrolysis of chloropentanes or by reaction of butene and carbon monoxide isomers. They are used as solvents for fats, resins and waxes. Pentan-1-ol is absorbed into the human body through the respiratory tract, skin, gastrointestinal tract. Symptoms of acute intoxication are usually tearing eyes, redness of the conjunctiva, irritation of the mucous membrane of the nose and throat. In higher concentrations it may cause headache, dizziness, nausea, vomiting, diarrhea, delirium, disturbances of consciousness, coma. Arrhythmia and respiratory disorders may cause redness and burning, as well as symptoms such as inhalation poisoning, eye contamination with liquid substance causes pain, burning of the eyes, redness of the conjunctiva, with the risk of long-lasting and permanent changes. Repeated skin contact with the liquid substance may cause its drying and inflammation. It is suggested that long-term exposure of the skin to the substance at high concentration may lead to changes in the nervous system. The aim of this study was to develop and validate a sensitive method of determining 8 pentan-1-ol isomers in the working environment in the range from 1/10 to 2 of the MAC values. The gas chromatography method with a flame ionization detector (GC-FID) was used to determine pentan-1-ol and its isomers. It was decided to develop a method that ensures the determination of at least 1/10 of the MAC values. Further considerations of the possibility of determining this substance in the air are based on previously developed analytical methods. The use of the HP-5 capillary column enables the selective determination of pentan-1-ol in the presence of carbon disulphide, methanol and other co-existing compounds. The detector's response to the analyzed pentan-1-ol concentrations is linear (r2 = 0.9998) in the concentration range 10–2000 μg/ml, which corresponds to the range of 1–200 mg/m3 (0.01–2 of the MAC values) for a 10-L air sample. The limit of quantification (LOQ) of this method is 0.026 μg/ml. The developed method is characterized by good precision and accuracy and meets the requirements of Standard No. PN-EN 482 for procedures regarding the determination of chemical agents. The developed method for determining pentan-1-ol has been recorded in the form of an analytical procedure (see Appendix). This article discusses the problems of occupational safety and health, which are covered by health sciences and environmental engineering.
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Velíšek, J., and K. Cejpek. "Biosynthesis of food constituents: Lipids. 1. Fatty acids and derivated compounds – a review." Czech Journal of Food Sciences 24, No. 5 (November 12, 2011): 193–216. http://dx.doi.org/10.17221/3317-cjfs.
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This review article gives a survey of the principal biosynthetic pathways that lead to the most important common fatty acids and their derivatives occurring in foods and feeds. Fatty acids are further subdivided to saturated fatty acids and unsaturated fatty acids. This review is focused on the less common fatty acids including geometrical and positional isomers of unsaturated fatty acids, acetylenic fatty acids, branched-chain fatty acids, alicyclic fatty acids, epoxy fatty acids, hydroxy fatty acids, and oxo fatty acids. A survey is further given on the biosynthesis of the aliphatic very-long-chain components (alkanes, primary and secondary alcohols, aldehydes, ketones, and esters) of plant cuticular wax derived from saturated fatty acids. Subdivision of the topics is predominantly via biosynthesis. There is extensive use of reaction schemes, sequences, and mechanisms with enzymes involved and detailed explanations using chemical principles and mechanisms.
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Knowles, Lisa O., N. Richard Knowles, and Jalpa P. Tewari. "Aliphatic components of the epicuticular wax of developing saskatoon (Amelanchier alnifolia) fruit." Canadian Journal of Botany 74, no. 8 (August 1, 1996): 1260–64. http://dx.doi.org/10.1139/b96-152.
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The epicuticular wax of saskatoon fruit (Amelanchier alnifolia Nutt. cv. Smoky) was analyzed at four stages of maturity. Total wax per unit surface area varied during fruit development, with a net decline from the youngest to the most ripe stage. Surface wax ultrastructure, as revealed by scanning electron microscopy, consisted of pinhead-like crystals that decreased with maturity and platelike crystals that increased with maturity. The major aliphatic compounds were alkanes (C23 to C29), long chain esters (C36 to C42), primary alcohols (C20 to C30), and a secondary alcohol (C29). The esters were composed of primary alcohols (C20 to C28) and saturated fatty acids (C16 to C24). The most abundant wax components at all stages were nonacosan-10-ol and nonacosane. Keywords: serviceberry, saskatoon fruit, epicuticular wax, aliphatic chemistry, ultrastructure.
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Clark, J. Marshall, J. R. Marion, L. J. Scarano, T. L. Potter, P. F. Gosselin, J. A. Argentine, and J. S. Elkinton. "NEUTRAL LIPID CONTENT AND FATTY ACID COMPOSITION OF 1,2-DIACYLGLYCEROLS IN THE HEMOLYMPH OF THE MALE GYPSY MOTH, LYMANTRIA DISPAR L. (LEPIDOPTERA: LYMANTRIIDAE)." Canadian Entomologist 122, no. 6 (December 1990): 1101–9. http://dx.doi.org/10.4039/ent1221101-11.
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AbstractQualitative and quantitative changes in the neutral lipid content of hemolymph of gypsy moths, Lymantria dispar L., were assayed in larval, pupal, and adult stages. The major neutral lipid constituents of the hemolymph were 1,2-diacylglycerols and ranged in nominal concentration from 1.6–3.4 (larval), 3.1–4.9(pupal),toamaximumof 19.3 μg lipid per microlitre hemolymph in the adult male. When detected, triacylglycerols and monoacylglycerols never exceed diacylglycerol concentrations. The fatty acid composition of 1,2-diacylglycerols from adult male moths (0–12 h after emergence) was determined as fatty acid methyl esters using gas chromatography/mass spectrometry analysis. Nine fatty acid structures have been assigned. Of these, five are saturated, unbranched, aliphatic fatty acids (C14:0 – C18:0) which comprise 80.5% of the total fatty acid abundance. The remaining four fatty acids consist of two saturated, methyl-branched, aliphatic compounds, a mono-unsaturated aliphatic acid, and a tri-unsaturated, tricyclic, diterpenoid acid.
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Pattanayak, Rojalin, Geetanjali Mishra, Chandan Singh Chanotiya, Prasant Kumar Rout, Chandra Sekhar Mohanty, and Omkar. "Semiochemical profile of four aphidophagous Indian Coccinellidae (Coleoptera)." Canadian Entomologist 148, no. 2 (August 3, 2015): 171–86. http://dx.doi.org/10.4039/tce.2015.45.
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AbstractThe emitted aliphatic hydrocarbon profile of four Indian Coccinellidae (Coleoptera), Coccinella septempunctata (Linnaeus) (C7), Coccinella transversalis Fabricius (Ct), Menochilus sexmaculatus (Fabricius) (Ms), and Propylea dissecta (Mulsant) (Pd) has been investigated by simple solvent-less headspace solid-phase microextraction (HS-SPME) technique coupled with gas chromatography and mass spectroscopy (GC-MS). Identified volatile and non-volatile compounds were confirmed by running corresponding standards and comparing with the National Institute of Standards and Technology library. Among the 56 identified aliphatic hydrocarbons, saturated aliphatic hydrocarbons were more in number than unsaturated ones. Among saturated hydrocarbons, methyl branched hydrocarbons were more in number in C7 and Ct than Ms and Pd. Menochilus sexmaculatus and Pd had higher percentages of unsaturated hydrocarbons than C7 and Ct. Among branched chain-hydrocarbons, mono-methylated saturated hydrocarbons were more in number than dimethylated saturated hydrocarbons. Further analysis of the semiochemical profile revealed a closeness between C7 and Ct, and between Ms and Pd. Quantitative analysis revealed that straight chain hydrocarbons form separate clusters to branched chain methylated hydrocarbons. This is the first attempt to identify the semiochemical profile of some Indian coccinellids using the headspace solid phase micro-extraction technique coupled with the gas chromatography-mass spectrometry technique. This report will be helpful for various chemotaxonomic studies of the species in the future.
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Setyawardhani, Dwi Ardiana, Hary Sulistyo, Wahyudi Budi Sediawan, and Mohammad Fahrurrozi. "PERANAN PENGADUKAN TERHADAP KARAKTERISTIK KOMPLEKSASI UREA SEBAGAI SARANA PEMISAHAN ASAM LEMAK OMEGA DARI MINYAK NABATI." REAKTOR 16, no. 2 (August 11, 2016): 81. http://dx.doi.org/10.14710/reaktor.16.2.81-86.
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Modern society concerns more on health, in which natural foods are highly preferred. Poly-Unsaturated Fatty Acids (PUFAs) such as omega 6 and omega 9 are believed to be very important on degeneratif prevention. The PUFAs intake as concentrate is preferred than the one of the whole oil, in order to avoid saturated fatty acids consumption to the human body. Omega 6 and omega 9 fatty acids are mainly content in the vegetable oil. One of the methods of concentrating PUFAs from the oil is urea complexation. For commercial scale, this is very interesting and promising process in Indonesia, which is rich in vegetable oil resources. This method consists of 3 steps : 1) saponification and acidification of the vegetable oil, 2) urea-complexation process and 3) recovery of the PUFAs. The urea-complexation is a separation process based on the molecular size of the aliphatic organic compounds. The objective of the research was to study the effects of mixing time on the crystallization step. This study showed that mixing-time could improve SFA and reduce PUFA in urea inclusion compound, which lead to SFA reduction and PUFA improvement in the concentrate. Mixing also affected the tendency of the fatty acids molecules to form inclusion with urea crystal, and enhanced the substitutions of the guest molecules, especially for polar fatty acids such as MUFA and PUFAs. Keywords : fatty acids, mixing-time, PUFA, urea complexation, vegetable oil. ABSTRAK Pentingnya hidup sehat menjadikan konsumsi bahan alami menjadi bagian dari gaya hidup modern. Salah satu nutrisi penting adalah asam lemak tak jenuh ganda (Poly Unsaturated Fatty Acid - PUFA), seperti omega 6 dan omega 9 yang berfungsi untuk mencegah berbagai penyakit degeneratif. Asam lemak omega 6 & 9 banyak terkandung di dalam minyak nabati. Konsumsi dalam bentuk konsentrat asam lemak dinilai lebih efektif karena asam lemak jenuh hanya sedikit yang terikut dalam konsumsi. Salah satu metode pengkonsentrasian PUFA adalah kompleksasi urea. Teknologi pengkonsentrasian PUFA sangat berpotensi untuk dikembangkan di dalam negeri mengingat Indonesia kaya akan sumber minyak nabati. Kompleksasi urea terdiri atas 3 tahapan yaitu 1) tahap penyiapan asam lemak bebas dari minyak nabati, 2) tahap kristalisasi (fraksinasi kompleksasi urea), dan 3) tahap pemungutan asam lemak tak jenuh. Proses ini didasarkan pada pemisahan asam lemak jenuh dan tak jenuh pada minyak nabati berdasarkan perbedaan ukuran diameter molekulnya. Tujuan penelitian ini adalah mempelajari pengaruh waktu pengadukan terhadap komposisi asam lemak melalui proses kompleksasi urea pada minyak nabati. Berdasarkan hasil penelitian ini, adanya pengadukan dapat meningkatkan kadar SFA dan menurunkan PUFA di fraksi kristal, yang berdampak pada penurunan kadar SFA di NUCF dan meningkatkan kadar PUFA di NUCF. Adanya pengadukan juga mempengaruhi tendensi asam lemak untuk masuk ke dalam kristal urea dan mempermudah pergantian guest molecules, khususnya bagi asam lemak polar seperti MUFA dan PUFA. Kata kunci : PUFA, asam lemak, kompleksasi urea, minyak nabati
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Bláha, Luděk, Jiří Damborský, and Miroslav Němec. "QSAR for acute toxicity of saturated and unsaturated halogenated aliphatic compounds." Chemosphere 36, no. 6 (March 1998): 1345–65. http://dx.doi.org/10.1016/s0045-6535(97)10020-0.
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Schuhmann, M., K. Altwegg, H. Balsiger, J. J. Berthelier, J. De Keyser, B. Fiethe, S. A. Fuselier, et al. "Aliphatic and aromatic hydrocarbons in comet 67P/Churyumov-Gerasimenko seen by ROSINA." Astronomy & Astrophysics 630 (September 20, 2019): A31. http://dx.doi.org/10.1051/0004-6361/201834666.
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Context. Unlike all previous cometary space missions, the Rosetta spacecraft accompanied its target, comet 67P/Churyumov-Gerasimenko, for more than two years on its way around the Sun. Thereby, an unexpected diversity and complexity of the chemical composition was revealed. Aims. Our first step of decrypting the exact chemical composition of the gaseous phase is the identifying and quantifying the bulk composition of the pure aromatic and aliphatic hydrocarbons. Methods. For this study, data from ROSINA–Double Focusing Mass Spectrometer (DFMS) onboard the Rosetta spacecraft and the laboratory twin model were used. A joint campaign of laboratory calibration measurements and space data analysis was performed to derive the hydrocarbon bulk composition for the post-inbound equinox period at 1.52 AU in May 2015. Furthermore, several other mission phases were investigated to determine the dependencies of season, location, and heliocentric distance on the relative abundances of hydrocarbons. Results. It is shown that the bulk composition of the gaseous phase includes a high number of aliphatic compounds such as methane, ethane, and propane, as well as the aromatic compounds benzene and toluene. Butane and pentane were successfully identified in measurements at closer distance to the comet in May 2016. Furthermore, the presence of hexane and heptane in the coma is confirmed on rare occasions during the mission. Their presence in DFMS space data appears to be linked to days or periods of high dust activity. In addition to the saturated aliphatic and aromatic compounds, a high number of remaining unsaturated species is present, which cannot be explained by fragmentation of saturated species or contribution from other organic molecules in addition to pure hydrocarbons. This indicates the existence of unsaturated aliphatic and aromatic hydrocarbon molecules in the coma of comet 67P.
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Arif, Y., and N. Lombarkia. "Variability Influence of the Volatile Compounds of Three Algerian Date Cultivars (Phoenix dactylifera L.) on Infestation Rates of the Date Moth [(Ectomyelois ceratoniae Zell. (Lepidoptera: Pyralidae)]." Cercetari Agronomice in Moldova 51, no. 3 (September 1, 2018): 111–24. http://dx.doi.org/10.2478/cerce-2018-0029.
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Abstract The date moth Ectomyelois ceratoniae Zeller (Lepidoptera; Pyralidae) is a serious pest for the dates production in Algerian oasis. Its dangerousness resides in its wide geographic distribution on various bioclimatics stages and his polyphagia on various hosts. In this context, to find out the impact of the dates volatile compounds on the date moth oviposition behavior. To do this, we conducted the following study, which is divided into two parts, one in the field and the other in the laboratory. This study investigated the effect of the biochemical profiles of three Algerian date cultivars (Deglet-Nour, Ghars and Degla-Beidha) on the infestation rates of the date moth. The monitoring infection rates in the field produced the following results: during the campaigns from 2011/2012 to 2014/2015 at the INRAA Sidi Mahdi-Touggourt station (Algeria), revealed that the cultivar Deglet-Nour is the most affected with a rate of 18.84%, followed by Ghars with 10.28% then Degla-Beidha with 6.66%. As for the extracts analysis of the three date cultivars with hexane were identified and quantifie via coupling gas chromatography / mass spectrometry (GC/MS). The analysis of the volatile compounds of the cultivars studied allowed to identify 110 compounds distributed in eight chemical classes (hydrocarbons (saturated aliphatic hydrocarbons, unsaturated aliphatic hydrocarbons, unsaturated monocyclic hydrocarbons, saturated monocyclic hydrocarbons, aromatic hydrocarbons, terpene hydrocarbons), alcohols, aldehydes, esters, ketones, amides, phenols and carboxylic acids), whose compounds are distributed as follows: 72 compounds for the Deglet-Nour, 38 compounds for the cultivar Ghars and 29 compounds for Degla-Beidha.
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Dhillon, J. K., and N. Shivaraman. "Biodegradation of cyanide compounds by a Pseudomonas species (S1)." Canadian Journal of Microbiology 45, no. 3 (March 1, 1999): 201–8. http://dx.doi.org/10.1139/w99-014.
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A Pseudomonas sp. (S1), isolated from soil by an enrichment technique was tested for its potential to degrade different cyanide compounds. Further, biodegradation/biotransformation of binary mixtures of the cyanide compounds by the culture was also studied. The results indicated that the culture could grow on the following nitriles by using them as carbon and nitrogen sources: acetonitrile, butyronitrile, acrylonitrile, adiponitrile, benzonitrile, glutaronitrile, phenylacetonitrile, and succinonitrile. Studies on the biodegradation of these cyanide compounds in binary mixtures showed that the presence of acrylonitrile or KCN delayed the degradation of acetonitrile in a mixture, while none of the other cyanide compounds affected the degradation of one another. The transformation products of the nitriles were their corresponding acids, and similarly, KCN was also directly transformed to formic acid. Studies on the transformation of these cyanide compounds showed that the rate of transformation of nitriles to their corresponding carboxylic acids was acrylonitrile > acetonitrile > adiponitrile > benzonitrile > KCN. This culture has the unique characteristic of transforming representatives of saturated aliphatic, aliphatic olefinic, aromatic, and aralkyl nitriles, as well as alkali cyanide, to their corresponding carboxylic acids.Key words: Pseudomonas sp.(S1), biodegradation, biotransformation, nitriles, cyanide.
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Gavrilko, T., I. Gnatyuk, V. Styopkin, N. Shcherban, J. Baran, and M. Drozd. "FTIR and DSC Studies of Binary Mixtures of Long-Chain Aliphatic Compounds: Lauric Acid – Cetyl-trimethylammonium Bromide." Ukrainian Journal of Physics 63, no. 5 (July 3, 2018): 413. http://dx.doi.org/10.15407/ujpe63.5.413.
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Structural and thermal properties of a solid-state binary mixture of long-chain cationic and anionic surfactants (so-called catanionic complexes) composed of cetyltrimethyl-ammonium bromide, [H3C–(CH2)15–N+(CH3)3]Br−(CTAB), and saturated fatty acid (FA), CH3(CH2)12COOH (lauric acid, kC12), are studied. To clarify the effect of intermolecular interactions on the crystalline structure and phase transitions in this class of supramolecular compounds, the 1 : 1 kC12-CTAB binary mixture is investigated by means of X-ray diffraction, differential scanning calorimetry (DSC), and temperature-variable Fourier transform infrared spectroscopy (FTIR). Based on the comparison of the obtained results with those of other CTAB-FA binary mixtures with different alkyl chain length mismatches, the possible molecular packing in the crystal phase of CTAB-FA complexes and the mechanism of successive phase transitions in the condensed state are proposed.
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Karateev, Arnold, Andrew Koryagin, Denis Litvinov, Ludmila Sumtsova, and Yana Taranukha. "New network polymers based on furfurylglycidyl ether." Chemistry & Chemical Technology 2, no. 1 (March 15, 2008): 19–26. http://dx.doi.org/10.23939/chcht02.01.019.
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Among the activities done under the present work are the following: - study of the kinetic regularities of the polymerization of new heterocyclic monomers and oligomers obtained from interaction between furfurylglycidyl ether and aliphatic monocarboxylic acids (saturated and unsaturated); -determination of the polymerization mechanism in the absence of complex onium catalysts; -determination of the structure and composition of monomeric and polymeric compounds by using chemical and physicochemical techniques and 1Н-NМR spectral analysis. The kinetic regularities for polymerization have been studied using Differential Scanning Calorimetry (DSC); study of the thermal resistance and thermal stability employed the derivatography techniques (DTA and TGA).
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Cotsaris, E., A. Bruchet, J. Mallevialle, and D. B. Bursill. "The identification of odorous metabolites produced from algal monocultures." Water Science and Technology 31, no. 11 (June 1, 1995): 251–58. http://dx.doi.org/10.2166/wst.1995.0443.
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Four algal species commonly found in the River Seine were cultured for a comprehensive investigation of their odorous metabolites. Closed loop stripping analysis (CLSA), open stripping analysis (OSA) and steam distillation extraction (SDE) were used to extract and concentrate a wide range of metabolites. The odour causing compounds were identified by a combination of chemical (gas chromatography-mass spectrometry (GC-MS)) and sensory (sensory-gas chromatography (sensory-GC), flavour profile analysis (FPA)) analyses. The compounds found responsible for unpleasant odours were alkenes, saturated and unsaturated aliphatic alcohols, aldehydes, ketones, sulphides and pyrazines. Some of the odorous compounds responsible for septic and muddy/musty odours may have been of bacterial or fungal origin as the cultures were non-axenic. Sensory-GC was found to be a valuable tool in identifying compounds of very low odour thresholds, which were present at or below the detection limits of the GC-MS.
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Alharbi, Wafa Nazzal, Waseem Sharaf Saeed, Abdulrahman A. Alwarthan, Ahmed Yacine Badjah-Hadj-Ahmed, and Taieb Aouak. "Extraction of Organic Volatile Pollutants in Over-Saturated Water by Pervaporation Technique Using a Poly (Dimethylsiloxane)-Based Sealer as a Membrane." Water 13, no. 8 (April 11, 2021): 1049. http://dx.doi.org/10.3390/w13081049.
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SILICONE1200 is an inexpensive domestic poly (dimethylsiloxane)-based sealer that was used in this study to remove volatile organic compounds from over-saturated water using the pervaporation technique. A series of volatile organic liquid compounds representing an important part of polluting organic products released every day in water were chosen for this study. These products were alkyl halides (chloroform), aromatics (toluene), aliphatic hydrocarbons (heptanes), ketones and aldehydes (butanone), and organosulfides (thiophene). The mass transfer of these compounds and their mixtures through the SILICONE1200 membrane was assessed to predict the results of the separation process. The results indicate that the mechanism of diffusion obeyed a Fickian model. Different parameters affecting the pervaporation results, such as the membrane thickness, stirring rate, and temperature, were examined to determine the optimal conditions in terms of the total flux and selectivity. The optimized parameters were then applied to the separation of an organic mixture from polluted water using the dynamic pervaporation process with promising results.
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April, T. M., S. P. Abbott, J. M. Foght, and R. S. Currah. "Degradation of hydrocarbons in crude oil by the ascomycetePseudallescheria boydii(Microascaceae)." Canadian Journal of Microbiology 44, no. 3 (March 1, 1998): 270–78. http://dx.doi.org/10.1139/w97-152.
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Four unique strains of Pseudallescheria boydii were isolated from oil-soaked soils in British Columbia and Alberta and compared to strains from cattle dung and raw sewage. Considerable variability in morphology, colony appearance, colony diameter, and temperature tolerance occurred among the strains. They also varied in the sporogenous states produced in culture; all strains had a Scedosporium anamorph and either the Graphium anamorph or cleistothecial teleomorph. Conspecificity of the six isolates was inferred from their morphology and supported by restriction fragment length polymorphism profiles of the internally transcribed spacer region of rDNA and comparing these to Petriella sordida, a similar taxon in the Microascaceae. Three of the strains isolated from oil-contaminated soil and the strain from sewage were tested for their ability to utilize hydrocarbons by incubation with Prudhoe Bay Crude oil as the sole carbon source. Gas chromatographic analysis of the residual oil revealed that the strains isolated from oil-contaminated soil degraded the linear aliphatics. The strain from sewage, previously shown by others to utilize the volatile n-alkanes (i.e., ethane, propane, and butane), did not utilize the liquid saturate compounds. None of the strains was observed to degrade compounds in the aromatic fraction. Pseudallescheria boydii may be an important agent for in situ bioremediation of saturates in oil-contaminated sites.Key words: bioremediation, filamentous fungi, Graphium, hydrocarbon degradation, Scedosporium.
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Ajjou, Abdelaziz Nait, and Jean-Louis Pinet. "Oppenauer-type oxidation of secondary alcohols catalyzed by homogeneous water-soluble complexes." Canadian Journal of Chemistry 83, no. 6-7 (June 1, 2005): 702–10. http://dx.doi.org/10.1139/v05-037.
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The catalytic system composed of [Ir(COD)Cl]2, 2,2′-biquinoline-4,4′-dicarboxylic acid dipotassium salt (BQC), and sodium carbonate is highly efficient for the selective oxidation of benzylic, 1-heteroaromatic, aliphatic, and allylic secondary alcohols using catalyst:substrate ratios ranging from 0.4% to 2.5%. Sterically hindered allylic alcohols undergo selectively good conversions to the corresponding enones, while unhindered ones are completely isomerized to saturated ketones. Mercury tests indicate that the catalytic process is likely homogeneous. The mechanism proposed for this Oppenauer-type oxidation including the isomerization process is based on iridium-alkoxide species.Key words: Oppenauer oxidation, water, catalysis, isomerization, secondary alcohols.
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Knols, Bart G. J., Joop J. A. van Loon, Alan Cork, Rosemary D. Robinson, Wim Adam, Jocelijn Meijerink, Ruurd De Jong, and Willem Takken. "Behavioural and electrophysiological responses of the female malaria mosquitoAnopheles gambiae(Diptera: Culicidae) to Limburger cheese volatiles." Bulletin of Entomological Research 87, no. 2 (April 1997): 151–59. http://dx.doi.org/10.1017/s0007485300027292.
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AbstractLimburger cheese, previously shown to attract femaleAnopheles gambiaeGiles, was solvent extracted and chemically fractionated into acid and non-acid fractions. The extracts and aliquots of headspace odour of the cheese were analysed by gas chromatography and electron impact mass spectrometry. Nineteen saturated and unsaturated aliphatic fatty acids, ranging in carbon chain length from C2to C18, were detected. The most abundant acids (>1 mg/g of cheese) identified in the acid extract were ethanoic, propanoic, butanoic, hexadecanoic and 9-octadecenoic acid. The same compounds were identified in analyses of headspace samples but only trace quantities of the less volatile acids (C10to C16) were present, whilst C18acids were absent. Behavioural responses of femaleA. gambiaetowards a range of dilutions of the acid extract (in diethyl ether) were recorded in a windtunnel bioassay. The undiluted extract was found to be repellent, but became highly attractive (P«0.001) at lower doses, and was still significantly attractive (P<0.001) when diluted 106times. A synthetic mixture of 12 of the more abundant aliphatic acids identified in the acid extract was found to be significantly attractive (P<0.001) when diluted 108times. Electroantennographic (EAG) studies showed significant and reproducible responses to (saturated) Limburger cheese headspace. At doses higher than 0.1%, the synthetic mixture of 12 acids elicited significantly higher EAG amplitudes than the solvent control (paraffin oil). EAG responses were recorded from mosquitoes stimulated with C5to C8acids, that were characterized by significant dose-dependencies. Weaker, though significant EAG responses were obtained with the less volatile acids (C9to C14). Only hexadecanoic acid did not elicit a detectable response. The electrophysiological and behavioural responses obtained with fatty acids isolated from Limburger cheese suggests that together they could act as a kairomone for femaleA. gambiae. The implications of this are discussed together with the occurrence and bacterial production of these compounds on human skin.
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Thring, Ronald W., Esteban Chornet, and Ralph P. Overend. "Fractionation of woodmeal by prehydrolysis and thermal organosolv. Alkaline depolymerization, chemical functionality, and molecular weight distribution of recovered lignins and their fractions." Canadian Journal of Chemistry 71, no. 6 (June 1, 1993): 779–89. http://dx.doi.org/10.1139/v93-103.
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Thermal organosolv glycol lignins and their fractions have been characterized by means of elemental composition, molecular weight distribution, and 1H and 13C NMR spectroscopy. Fractionation of each lignin by sequential solvent extraction produced fractions of increasing molecular weight and polydispersity. Structures in the highest molecular weight fractions were found to be linked by a high proportion of β-O-4 type bonds, whilst the lowest molecular weight fractions consisted of a high content of saturated aliphatic side-chain structures. A noticeable difference in the content of carbohydrate contaminants in both starting lignins indicated the formation of relatively stable lignin–carbohydrate complexes, especially in the lignin recovered from pretreated wood. In addition, depolymerization of the lignins and their fractions to monomeric compounds was explored using alkaline hydrolytic and nitrobenzene oxidative routes. The highest molecular weight fractions from each lignin were identified as the best candidates for production of useful monomeric phenolic compounds.
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Liang, T., and S. Liao. "Inhibition of steroid 5α-reductase by specific aliphatic unsaturated fatty acids." Biochemical Journal 285, no. 2 (July 15, 1992): 557–62. http://dx.doi.org/10.1042/bj2850557.
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Human or rat microsomal 5 alpha-reductase activity, as measured by enzymic conversion of testosterone into 5 alpha-dihydrotestosterone or by binding of a competitive inhibitor, [3H]17 beta-NN-diethulcarbamoyl-4-methyl-4-aza-5 alpha-androstan-3-one ([3H]4-MA) to the reductase, is inhibited by low concentrations (less than 10 microM) of certain polyunsaturated fatty acids. The relative inhibitory potencies of unsaturated fatty acids are, in decreasing order: gamma-linolenic acid greater than cis-4,7,10,13,16,19-docosahexaenoic acid = cis-6,9,12,15-octatetraenoic acid = arachidonic acid = alpha-linolenic acid greater than linoleic acid greater than palmitoleic acid greater than oleic acid greater than myristoleic acid. Other unsaturated fatty acids such as undecylenic acid, erucic acid and nervonic acid, are inactive. The methyl esters and alcohol analogues of these compounds, glycerols, phospholipids, saturated fatty acids, retinoids and carotenes were inactive even at 0.2 mM. The results of the binding assay and the enzymic assay correlated well except for elaidic acid and linolelaidic acid, the trans isomers of oleic acid and linoleic acid respectively, which were much less active than their cis isomers in the binding assay but were as potent in the enzymic assay. gamma-Linolenic acid had no effect on the activities of two other rat liver microsomal enzymes: NADH:menadione reductase and glucuronosyl transferase. gamma-Linolenic acid, the most potent inhibitor tested, decreased the Vmax. and increased Km values of substrates, NADPH and testosterone, and promoted dissociation of [3H]4-MA from the microsomal reductase. gamma-Linolenic acid, but not the corresponding saturated fatty acid (stearic acid), inhibited the 5 alpha-reductase activity, but not the 17 beta-dehydrogenase activity, of human prostate cancer cells in culture. These results suggest that unsaturated fatty acids may play an important role in regulating androgen action in target cells.
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Butturini, Andrea, Stefano Amalfitano, Peter Herzsprung, Oliver J. Lechtenfeld, Stefania Venturi, Lydia A. Olaka, Nic Pacini, David M. Harper, Franco Tassi, and Stefano Fazi. "Dissolved Organic Matter in Continental Hydro-Geothermal Systems: Insights from Two Hot Springs of the East African Rift Valley." Water 12, no. 12 (December 14, 2020): 3512. http://dx.doi.org/10.3390/w12123512.
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Little is known about the quantity and quality of dissolved organic matter (DOM) in waters from continental geothermal systems, with only a few reports available from the Yellowstone US National Park. In this study, we explored the chemodiversity of DOM in water samples collected from two geothermal hot springs from the Kenyan East African Rift Valley, a region extremely rich in fumaroles, geysers, and spouting springs, located in close proximity to volcanic lakes. The DOM characterization included in-depth assessments performed by negative electrospray ionization Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). Reduced, saturated and little aromatic DOM compounds were dominant in the hot spring waters collected from either the Ol Njorowa gorge (ON) or the south shore of the soda-saline Lake Elementaita (ELM). Oxygen-poor and sulfur-bearing DOM molecules prevailed in ON, probably reflecting abiotic sulfurization from sulfide-rich geofluids. Nitrogen-bearing aliphatic and protein-like molecules were abundant in ELM, possibly perfusing through the organic-rich sediments of the adjacent Lake Elementaita. Notably, the heat-altered DOM of ancient autochthonous derivation could represent an overlooked source of aliphatic organic carbon for connected lentic environments, with a potential direct impact on nutrient cycling in lakes that receive geothermal water inputs.
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Lesnov, Andrey E., Peter T. Pavlov, Larisa V. Pustovik, and Irina А. Sarana. "1-ALKYL-3-METHYL-4-HYDROXYIMINO-2-PYRAZOLINE-5-ONES AS EXTRACTION REAGENTS." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 60, no. 5 (June 23, 2017): 30. http://dx.doi.org/10.6060/tcct.2017605.5527.
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With nitrosation of the corresponding 1-R-3-methylpyrazole-5-one (R = C4H9, C5H11, C6H13, C7H15, C8H17, C6H5) in acidic aqueous methanolic medium at 0-5 °C a series of 1-alkyl-3-methyl-4-hydroxyimino-2-pyrazolin-5-ones with a yield of 72-85% were synthesized. The compounds are soluble in CHCl3, C2H4Cl2, C6H5CH3, i-C4H9OH, CCl4, C2H5OH, slightly soluble in C6H14, H2O. They can be recrystallized from a mixture of C6H14: C6H5CH3 = 5: 1 or isooctane. The structure of the compounds was confirmed by the data of ECR, IR, Raman spectroscopy and TLC data. The interphase distribution of oxyiminopyrazolones between chloroform and aqueous solutions was studied as a function of pH. In alkaline media, the reagents completely transferred into the aqueous phase. In acidic solutions, up to 1 mol/l HCl, the compounds are in the organic phase. The maximum values of the partition coefficient are observed for the reagents with the maximum length of the aliphatic radical. The effect of the length of aliphatic radical at the first position of the pyrazoline ring on their extraction properties were studied by example of extraction of nickel and copper (II) ions. The length of the radical does not affect the composition of the recoverable complexes of nickel and copper (II). In all cases the ratio is close to 1:2. Extraction proceeds through a cation-exchange mechanism. Replacement of the phenyl radical in the first position of the pyrazoline ring by an aliphatic resulted to the increase in partition constants of the reagents between chloroform and aqueous solutions. The range of pH values of the maximum extraction of elements was widened. The capacity of the extractant for metals also increased. At the same time, the pH50 extraction values remained practically unchanged. In the case of 0.05 mol/l solution of 1-phenyl-3-methyl-4-oxyimino-2-pyrazolin-5-one in chloroform, when the extract was saturated with the metal ion, precipitation of the complex was observed.For citation:Lesnov A.E., Pavlov P.T., Pustovik L.V., Sarana I.A. 1-Alkyl-3-methyl-4-hydroxyimino-2-pyrazoline-5-ones as extraction reagents. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 5. P. 30-36.
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Freire, C. S. R., A. J. D. Silvestre, and C. Pascoal Neto. "Oxidized Derivatives of Lipophilic Extractives Formed during Hardwood Kraft Pulp Bleaching." Holzforschung 57, no. 5 (August 20, 2003): 503–12. http://dx.doi.org/10.1515/hf.2003.075.
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Summary The structural changes of E. globulus wood extractives during bleaching with chlorine dioxide (D), oxygen (O), ozone (Z) and hydrogen peroxide (P) were studied. The detailed characterisation of the extractive derivatives detected in the partially bleached D, O, P and Z pulps was achieved by performing reactions of pure reference compounds with the different bleaching agents. The results show that the unsaturated sterols and fatty acids are extensively degraded during chlorine dioxide and ozone bleaching and only partially degraded during oxygen and hydrogen peroxide bleaching. The corresponding saturated extractives as well as the long chain aliphatic alcohols and ω-hydroxyfatty acids were stable during bleaching. The main oxidation products of β-sitosterol and oleic and linoleic acids, including one chlorinated derivative of linoleic acid, were identified here for the first time in E. globulus bleached pulps and bleaching filtrates.
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Musat, Florin, Carsten Vogt, and Hans H. Richnow. "Carbon and Hydrogen Stable Isotope Fractionation Associated with the Aerobic and Anaerobic Degradation of Saturated and Alkylated Aromatic Hydrocarbons." Journal of Molecular Microbiology and Biotechnology 26, no. 1-3 (2016): 211–26. http://dx.doi.org/10.1159/000442161.
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Saturated hydrocarbons (alkanes) and alkylated aromatic hydrocarbons are abundant environmental compounds. Hydrocarbons are primarily removed from the environment by biodegradation, a process usually associated with moderate carbon and significant hydrogen isotope fractionation allowing monitoring of biodegradation processes in the environment. Here, we review the carbon and hydrogen stable isotope fractionation associated with the cleavage of C-H bonds at alkyl chains of hydrocarbons. Propane, <i>n</i>-butane and ethylbenzene were used as model components for alkyl moieties of aliphatic and aromatic hydrocarbons with emphasis on the cleavage of the C-H bond without the involvement of molecular oxygen. The carbon and hydrogen isotope fractionation factors were further used to explore the diagnostic potential for characterizing the mode of bond cleavage under oxic and anoxic conditions. Λ factors, calculated to correlate carbon and hydrogen fractionation, allowed to distinguish between aerobic and anaerobic biodegradation processes in the environment.
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Teltayev, B., and T. Seilkhanov. "NMR-Spectroscopy Determination of Fragmentary Composition of Bitumen and its Components." Eurasian Chemico-Technological Journal 20, no. 2 (June 30, 2018): 153. http://dx.doi.org/10.18321/ectj696.
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This paper represents and discusses the results of quantitative determination for fragmentary composition of road bitumen of grade BND 100/130 and its components (asphaltenes, resins and oils) by NMR spectroscopy method. Group chemical composition of the bitumen has been determined by adsorption chromatography method. It has been identified that the bitumen and its components consist only of aromatic and aliphatic protons, which account for 2.4‒10.2% and 9.8‒97.6% respectively. Availability of olefinic elements in them has not been identified. The most part (79‒81%) of nuclei of carbon atoms relates to quaternary carbon atoms of saturated compounds. Primary carbon atoms at methylene group (CH2) are contained in the least quantity: bitumen ‒ 1.32%; asphaltenes – 0.6%; resins – 3.24% and oils – 2.11%. Primary carbon atoms, linked with CH-group or aromatic nucleus, occupy an intermediate position and are contained in the quantity of 17‒20%.
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Park, Soo J., Gunjan Pandey, Cynthia Castro-Vargas, John G. Oakeshott, Phillip W. Taylor, and Vivian Mendez. "Cuticular Chemistry of the Queensland Fruit Fly Bactrocera tryoni (Froggatt)." Molecules 25, no. 18 (September 12, 2020): 4185. http://dx.doi.org/10.3390/molecules25184185.
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The cuticular layer of the insect exoskeleton contains diverse compounds that serve important biological functions, including the maintenance of homeostasis by protecting against water loss, protection from injury, pathogens and insecticides, and communication. Bactrocera tryoni (Froggatt) is the most destructive pest of fruit production in Australia, yet there are no published accounts of this species’ cuticular chemistry. We here provide a comprehensive description of B. tryoni cuticular chemistry. We used gas chromatography-mass spectrometry to identify and characterize compounds in hexane extracts of B. tryoni adults reared from larvae in naturally infested fruits. The compounds found included spiroacetals, aliphatic amides, saturated/unsaturated and methyl branched C12 to C20 chain esters and C29 to C33 normal and methyl-branched alkanes. The spiroacetals and esters were found to be specific to mature females, while the amides were found in both sexes. Normal and methyl-branched alkanes were qualitatively the same in all age and sex groups but some of the alkanes differed in amounts (as estimated from internal standard-normalized peak areas) between mature males and females, as well as between mature and immature flies. This study provides essential foundations for studies investigating the functions of cuticular chemistry in this economically important species.
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Chalbot, M. C. G., J. Brown, P. Chitranshi, G. Gamboa da Costa, E. D. Pollock, and I. G. Kavouras. "Functional characterization of the water-soluble organic carbon of size fractionated aerosol in the Southern Mississippi Valley." Atmospheric Chemistry and Physics Discussions 14, no. 3 (February 10, 2014): 3629–66. http://dx.doi.org/10.5194/acpd-14-3629-2014.
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Abstract. The chemical content of the water soluble organic carbon (WSOC) as a function of particle size was characterized in Little Rock, Arkansas in winter and spring 2013. The objectives of this study were to: (i) compare the functional characteristics of coarse, fine and ultrafine WSOC and (ii) reconcile the sources of WSOC for the period when carbonaceous aerosol was the most abundant particulate component. The WSOC accounted for 5% of particle mass for particles with dp > 0.96 μm and 10% of particle mass for particles with dp < 0.96 μm. Non-exchangeable aliphatic (H-C), unsaturated aliphatic (H-C-C=), oxygenated saturated aliphatic (H-C-O), acetalic (O-CH-O) and aromatic (Ar-H) protons were determined by proton nuclear magnetic resonance. The total non-exchangeable organic hydrogen concentrations varied from 4.1 ± 0.1 nmol m−3 for particles with 0.96 < dp < 1.5 μm to 73.9 ± 12.3 nmol m−3 for particles with dp < 0.49 μm, resulting in molar H / C ratios of 0.48 ± 0.05 to 0.92 ± 0.09 observed in combustion-related organic aerosol. The R-H was the most abundant group representing about 45% of measured total non-exchangeable organic hydrogen concentration followed by H-C-O (27%) and H-C-C= (26%). Levoglucosan, amines, ammonium and methanosulfonate were tentatively identified in NMR fingerprints of fine particles. Sucrose, fructose, glucose, formate and acetate were associated with coarse particles. These qualitative differences of 1H-NMR profiles for different particle sizes indicated the possible contribution of biological aerosol and a mixture of aliphatic and oxygenated compounds from biomass burning and traffic exhausts. The concurrent presence of ammonium and amines also suggested the presence of ammonium/aminium nitrate and sulfate secondary aerosol. The size-dependent origin of WSOC was further corroborated by the increasing δ13C abundance from −26.81 ± 0.18‰ for the smallest particles to −25.93 ± 0.31‰ for the largest particles and the relative distribution of the functional groups as compared to those previously observed for marine, biomass burning and secondary organic aerosol. The latter also allowed for the differentiation of urban combustion-related aerosol and biological particles. The five types of organic hydrogen accounted for the majority of WSOC for particles with dp > 3.0 μm and dp < 0.96 μm.
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Vila, Joaquim, and Magdalena Grifoll. "Actions of Mycobacterium sp. Strain AP1 on the Saturated- and Aromatic-Hydrocarbon Fractions of Fuel Oil in a Marine Medium." Applied and Environmental Microbiology 75, no. 19 (August 7, 2009): 6232–39. http://dx.doi.org/10.1128/aem.02726-08.
Full textAbstract:
ABSTRACT The pyrene-degrading Mycobacterium sp. strain AP1 grew in nutrient-supplemented artificial seawater with a heavy fuel oil as the sole carbon source, causing the complete removal of all linear (C12 to C40) and branched alkanes from the aliphatic fraction, as well as an extensive degradation of the three- and four-ring polycyclic aromatic hydrocarbons (PAHs) phenanthrene (95%), anthracene (80%), fluoranthene (80%), pyrene (75%), and benzo(a)anthracene (30%). Alkylated PAHs, which are more abundant in crude oils than the nonsubstituted compounds, were selectively attacked at extents that varied from more than 90% for dimethylnaphthalenes, methylphenanthrenes, methylfluorenes, and methyldibenzothiophenes to about 30% for monomethylated fluoranthenes/pyrenes and trimethylated phenanthrenes and dibenzothiophenes. Identification of key metabolites indicated the utilization of phenanthrene, pyrene, and fluoranthene by known assimilatory metabolic routes, while other components were cooxidized. Detection of mono- and dimethylated phthalic acids demonstrated ring cleavage and further oxidation of alkyl PAHs. The extensive degradation of the alkanes, the two-, three-, and four-ring PAHs, and their 1-, 2-, and 3-methyl derivatives from a complex mixture of hydrocarbons by Mycobacterium sp. strain AP1 illustrates the great substrate versatility of alkane- and PAH-degrading mycobacteria.
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Espinoza, Javier, Cristian Medina, Alejandra Calabi-Floody, Elsa Sánchez-Alonso, Gonzalo Valdés, and Andrés Quiroz. "Evaluation of Reductions in Fume Emissions (VOCs and SVOCs) from Warm Mix Asphalt Incorporating Natural Zeolite and Reclaimed Asphalt Pavement for Sustainable Pavements." Sustainability 12, no. 22 (November 17, 2020): 9546. http://dx.doi.org/10.3390/su12229546.
Full textAbstract:
Conventional asphalt mixtures used for road paving require high manufacturing temperatures and therefore high energy expenditure, which has a negative environmental impact and creates risk in the workplace owing to high emissions of pollutants, greenhouse gases, and toxic fumes. Reducing energy consumption and emissions is a continuous challenge for the asphalt industry. Previous studies have focused on the reduction of emissions without characterizing their composition, and detailed characterization of volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs) in asphalt fumes is scarce. This communication describes the characterization and evaluation of VOCs and SVOCs from asphalt mixtures prepared at lower production temperatures using natural zeolite; in some cases, reclaimed asphalt pavement (RAP) was used. Fumes were extracted from different asphalt mix preparations using a gas syringe and then injected into hermetic gas sample bags. The compounds present in the fumes were sampled with a fiber and analyzed by gas-liquid chromatography coupled to mass spectrometry (GC/MS). In general, the preparation of warm mix asphalts (WMA) using RAP and natural zeolite as aggregates showed beneficial effects, reducing VOCs and SVOCs compared to hot mix asphalts (HMA). The fumes captured presented a similar composition to those from HMA, consisting principally of saturated and unsaturated aliphatic hydrocarbons and aromatic compounds but with few halogenated compounds and no polycyclic aromatic hydrocarbons. Thus, the paving mixtures described here are a friendlier alternative for the environment and for the health of road workers, in addition to permitting the re-use of RAP.
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Montgomery, J. A., M. Jetté, S. Huot, and C. Des Rosiers. "Acyloin production from aldehydes in the perfused rat heart: the potential role of pyruvate dehydrogenase." Biochemical Journal 294, no. 3 (September 15, 1993): 727–33. http://dx.doi.org/10.1042/bj2940727.
Full textAbstract:
Aldehydes represent an important class of cytotoxic products derived from free radical-induced lipid peroxidation which may contribute to reperfusion injury following myocardial infarct. Metabolism of aldehydes in the heart has not been well characterized aside from conjugation of unsaturated aldehydes with glutathione. However, aliphatic aldehydes like hexanal do not form stable glutathione conjugates. We have recently demonstrated in vitro that pig heart pyruvate dehydrogenase catalyses a reaction between pyruvate and saturated aldehydes to produce acyloins (3-hydroxyalkan-2-ones). In the present study, rat hearts were perfused with various aldehydes and pyruvate. Acyloins were generated from saturated aldehydes (butanal, hexanal or nonanal), but not from 2-hexanal (an unsaturated aldehyde) or malondialdehyde. Hearts perfused with 2 mM pyruvate and 10-100 microM hexanal rapidly took up hexanal in a dose-related manner (140-850 nmol/min), and released 3-hydroxyoctan-2-one (0.7-30 nmol/min), 2,3-octanediol (0-12 nmol/min) and hexanol (10-200 nmol/min). Small quantities of hexanoic acid (about 10 nmol/min) were also released. The rate of release of acyloin metabolites rose with increased concentration of hexanal, whereas hexanol release attained a plateau when hexanal infusion concentrations rose above 50 microM. Up to 50% of hexanal uptake could be accounted for by metabolite release. Less than 0.5% of hexanal uptake was found to be bound to acid-precipitable macromolecules. When hearts perfused with 50 microM hexanal and 2 mM pyruvate were subjected to a 15 min ischaemic period, the rates of release of 2,3-octanediol, 3-hydroxyoctan-2-one, hexanol and hexanoate during the reperfusion period were not significantly different from those in the pre-ischaemic period. Our results indicate that saturated aldehydes can be metabolically converted by the heart into stable diffusible compounds.
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Chalbot, M. C. G., J. Brown, P. Chitranshi, G. Gamboa da Costa, E. D. Pollock, and I. G. Kavouras. "Functional characterization of the water-soluble organic carbon of size-fractionated aerosol in the southern Mississippi Valley." Atmospheric Chemistry and Physics 14, no. 12 (June 20, 2014): 6075–88. http://dx.doi.org/10.5194/acp-14-6075-2014.
Full textAbstract:
Abstract. The chemical content of water-soluble organic carbon (WSOC) as a function of particle size was characterized in Little Rock, Arkansas in winter and spring 2013. The objectives of this study were to (i) compare the functional characteristics of coarse, fine and ultrafine WSOC and (ii) reconcile the sources of WSOC for periods when carbonaceous aerosol was the most abundant particulate component. The WSOC accounted for 5% of particle mass for particles with dp > 0.96 μm and 10% of particle mass for particles with dp < 0.96 μm. Non-exchangeable aliphatic (H–C), unsaturated aliphatic (H–C–C=), oxygenated saturated aliphatic (H–C–O), acetalic (O–CH–O) and aromatic (Ar–H) protons were determined by proton nuclear magnetic resonance (1H-NMR). The total non-exchangeable organic hydrogen concentrations varied from 4.1 ± 0.1 nmol m−3 for particles with 1.5 < dp < 3.0 μm to 73.9 ± 12.3 nmol m−3 for particles with dp < 0.49 μm. The molar H / C ratios varied from 0.48 ± 0.05 to 0.92 ± 0.09, which were comparable to those observed for combustion-related organic aerosol. The R–H was the most abundant group, representing about 45% of measured total non-exchangeable organic hydrogen concentrations, followed by H–C–O (27%) and H–C–C= (26%). Levoglucosan, amines, ammonium and methanesulfonate were identified in NMR fingerprints of fine particles. Sucrose, fructose, glucose, formate and acetate were associated with coarse particles. These qualitative differences of 1H-NMR profiles for different particle sizes indicated the possible contribution of biological aerosols and a mixture of aliphatic and oxygenated compounds from biomass burning and traffic exhausts. The concurrent presence of ammonium and amines also suggested the presence of ammonium/aminium nitrate and sulfate secondary aerosol. The size-dependent origin of WSOC was further corroborated by the increasing δ13C abundance from −26.81 ± 0.18‰ for the smallest particles to −25.93 ± 0.31‰ for the largest particles and the relative distribution of the functional groups as compared to those previously observed for marine, biomass burning and secondary organic aerosol. The latter also allowed for the differentiation of urban combustion-related aerosol and biological particles. The five types of organic hydrogen accounted for the majority of WSOC for particles with dp > 3.0 μm and dp < 0.96 μm.
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Nazaruk, Jolanta, Ewa Karna, and Danuta Kalemba. "The Chemical Composition of the Essential Oils of Cirsium palustre and C. rivulare and their Antiproliferative Effect." Natural Product Communications 7, no. 2 (February 2012): 1934578X1200700. http://dx.doi.org/10.1177/1934578x1200700242.
Full textAbstract:
The composition of the essential oils of Cirsium palustre and C. rivulare and their antiproliferative activity against breast adenocarcinoma cells (MCF-7 and MDA-MBA-231) were investigated. The essential oils obtained by hydro-distillation from the roots (yield 0.2 and 0.1% v/w, respectively), leaves and inflorescences (yield below 0.01%), were analyzed by gas chromatography coupled with mass spectrometry (GC-MS). The composition of the essential oils in the respective organs of each plant differed considerably. On the other hand, similarities were observed in the composition of root and leaf oils. In C. palustre and C. rivulare root oil, 50 and 39 constituents were identified, accounting for 95.3% and 92.4% of the total content. The main components were aplotaxene and its derivatives, representing 78.6% and 46.6% of the total content. In leaf oils of both species, 59 and 49 compounds, respectively, were identified, representing 67.4% and 78.3% of the total content. The major constituents were β-damascenone (4.1% and 13.4%, respectively) and β-ionone (6.7% and 5.3%, respectively). Short-chain saturated and unsaturated aliphatic alcohols and aldehydes constituted another important group of compounds (17.7% and 9.0%, respectively). The essential oils of the roots have moderate anti-proliferative activity, with IC50 values ranging from 110 to 140 μg/mL. These concentrations were below the level able to inhibit the proliferation of healthy cells.
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Headley, John V., Kerry M. Peru, Dena W. Mcmartin, and Marcus Winkler. "Determination of Dissolved Naphthenic Acids in Natural Waters by Using Negative-Ion Electrospray Mass Spectrometry." Journal of AOAC INTERNATIONAL 85, no. 1 (January 1, 2002): 182–87. http://dx.doi.org/10.1093/jaoac/85.1.182.
Full textAbstract:
Abstract Naphthenic acids (NAs) have been implicated as some of the most toxic substances in oil sands leachates and identified as priority substances impacting on aquatic environments. As a group of compounds, NAs are not well characterized and comprise a large group of saturated aliphatic and alicyclic carboxylic acids found in hydrocarbon deposits (petroleum, oil sands bitumen, and crude oils). Described is an analytical method using negative-ion electrospray ionization mass spectrometry (ES/MS) of extracts. Preconcentration was achieved by using a solid-phase extraction procedure utilizing a crosslinked polystyrene-based polymer with acetonitrile elution. Recovery of the Fluka Chemicals NA mixture was highly pH-dependent, with 100% recovery at pH 3.0, but only 66 and 51% recoveries at pHs 7 and 9, respectively. The dissolved phase of the NA was very dependent on sample pH. It is thus critical to measure the pH and determine the appropriate mass profiles to identify NAs in natural waters. The ES/MS analytical procedure proved to be a fast and sensitive method for the recovery and detection of NAs in natural waters, with a detection limit of 0.01 mg/L.
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González-Gamboa, Nancy, Xochitl Domínguez-Benetton, Daniella Pacheco-Catalán, Sathish Kumar-Kamaraj, David Valdés-Lozano, Jorge Domínguez-Maldonado, and Liliana Alzate-Gaviria. "Effect of Operating Parameters on the Performance Evaluation of Benthic Microbial Fuel Cells Using Sediments from the Bay of Campeche, Mexico." Sustainability 10, no. 7 (July 13, 2018): 2446. http://dx.doi.org/10.3390/su10072446.
Full textAbstract:
Benthic microbial fuel cells (BMFC) are devices that remove organic matter (OM) and generate energy from sediments rich in organic nutrients. They are composed of electrodes with adequate different distances and floating air cathodes in an aqueous medium with saturated oxygen. In this study we proposed to design, build, analyze and evaluate a set of BMFCs with floating air cathodes to test the optimal distance between the electrodes, using sediment from the Bay of Campeche as a substrate. For the analysis of OM removal, COD tests, volatile solids (VS), E4/E6 study and FTIR analysis were performed. Power generation was evaluated through polarization curves, cyclic voltammetry and electrochemical impedance spectroscopy (EIS). We achieved a current density and power density at 10 cm depth of 929.7 ± 9.5 mA/m2 and 109.6 ± 7.5 mW/m2 respectively, with 54% removal of OM from the sediment, obtaining formation of aliphatic structures. BMFCs are proposed as adequate systems for bioremediation and power generation. The system at 10 cm depth and 100 cm distance between sediment and the floating air cathode had a good performance and therefore the potential for possible scaling.
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Beskoski, Vladimir, Milos Takic, Jelena Milic, Mila Ilic, Gordana Gojgic-Cvijovic, Branimir Jovancicevic, and Miroslav Vrvic. "Change of isoprenoids, steranes and terpanes during ex situ bioremediation of mazut on industrial level." Journal of the Serbian Chemical Society 75, no. 11 (2010): 1605–16. http://dx.doi.org/10.2298/jsc100505091b.
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The paper presents results of the ex situ bioremediation of soil contaminated by mazut (heavy residual fuel oil) in the field scale (600 m3). A treatment-bed (thickness 0.4 m) consisted of mechanically mixed mazut-contaminated soil, softwood sawdust as the additional carbon source and crude river sand, as bulking and porosity increasing material. The inoculation/reinoculation was conducted periodically using a biomass of a consortium of zymogenous microorganisms isolated from the bioremediation substrate. The biostimulation was performed through addition of nutritious substances (N, P and K). The aeration was improved by systematic mixing of the bioremediation system. After 50 days, the number of hydrocarbon degraders increased 100 times. Based on the changes in the group composition, the average biodegradation rate during bioremediation was 24 mg/kg/day for the aliphatic fraction, 6 mg/kg/day for the aromatic fraction, and 3 mg/kg/day for the nitrogen-sulphuroxygen compounds (NSO)-asphaltene fraction. In the saturated hydrocarbon fraction, gas chromatography-mass spectrometry (GC-MS) in the single ion-monitoring mode (SIM) was applied to analyse isoprenoids pristane and phytane and polycyclic molecules of sterane and triterpane type. Biodegradation occurred during the bioremediation process, as well as reduction of relative quantities of isoprenoids, steranes, tri- and tetracyclic terpanes and pentacyclic terpanes of hopane type.
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Ivanenkо, I. I., and E. Y. Lapatina. "Sulfate as a terminal electron acceptor in toluene oxidation in anaerobic conditions." Vestnik Tomskogo gosudarstvennogo arkhitekturno-stroitel'nogo universiteta. JOURNAL of Construction and Architecture 22, no. 4 (August 27, 2020): 157–67. http://dx.doi.org/10.31675/1607-1859-2020-22-4-157-167.
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In aerobic conditions, many of microorganisms cause decomposition of saturated hydrocarbons. Little publications are available relative to anaerobic transformation of these compounds, which provides substantial сapiltal saving for waste water treatment. At the same time, cultures found among aerobic decomposers of petroleum products are characterized by the ability to use elements with variable valence as terminal electron acceptors in oxidation of organic substances. Their ability to decompose aliphatic hydrocarbons helps to identify some of them.Purpose: studying the ability of a selected association of immobilized bacteria on a fibrous carrier to utilize sulfate as a terminal electron acceptor for toluene oxidation.Methodology/approach: Analytical summarizing of results, literature review, laboratory research based on standard and modern up-to-date methodologies with the use of modern analytical equipment.Findings: The availability of using microorganism selection is shown for expanding the range of polluting strippants in biological purification; the main directions are determined for the process intensification by immobilization of active sludge on a fibrous carrier. The ability of microorganisms to oxidize toluene under oxygen-free (anaerobic) conditions is studied in the laboratory conditions.Research implications: monoaromatic hydrocarbons, toluene, in particular, can be changed by selected associations of decomposers using terminal electron acceptors in oxidation of nitrates and sulfates.
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McGillen, M. R., C. J. Percival, G. Pieterse, L. A. Watson, and D. E. Shallcross. "Predicting arene rate coefficients with respect to hydroxyl and other free radicals in the gas-phase: a simple and effective method using a single topological descriptor." Atmospheric Chemistry and Physics 7, no. 13 (July 6, 2007): 3559–69. http://dx.doi.org/10.5194/acp-7-3559-2007.
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Abstract. The reactivity of aromatic compounds is of great relevance to pure and applied chemical disciplines, yet existing methods for estimating gas-phase rate coefficients for their reactions with free radicals lack accuracy and universality. Here a novel approach is taken, whereby strong relationships between rate coefficients of aromatic hydrocarbons and a Randić-type topological index are investigated, optimized and developed into a method which requires no specialist software or computing power. Measured gas-phase rate coefficients for the reaction of aromatic hydrocarbons with OH radicals were correlated with a calculated Randić-type index, and optimized by including a term for side chain length. Although this method is exclusively for use with hydrocarbons, it is more diverse than any single existing methodology since it incorporates alkenylbenzenes into correlations, and can be extended towards other radical species such as O(3P) (and tentatively NO3, H and Cl). A comparison (with species common to both techniques) is made between the topological approach advocated here and a popular approach based on electrophilic subsituent constants, where it compares favourably. A modelling study was carried out to assess the impact of using estimated rate coefficients as opposed to measured data in an atmospheric model. The difference in model output was negligible for a range of NOx concentrations, which implies that this method has utility in complex chemical models. Strong relationships (e.g. for OH, R2=0.96) between seemingly diverse compounds including benzene, multisubstituted benzenes with saturated, unsaturated, aliphatic and cyclic substitutions and the nonbenzenoid aromatic, azulene suggests that the Randić-type index presented here represents a new and effective way of describing aromatic reactivity, based on a quantitative structure-activity relationship (QSAR).
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McGillen, M. R., C. J. Percival, G. Pieterse, L. A. Watson, and D. E. Shallcross. "Predicting arene rate coefficients with respect to hydroxyl and other free radicals in the gas-phase: a simple and effective method using a single topological descriptor." Atmospheric Chemistry and Physics Discussions 7, no. 1 (February 26, 2007): 2961–89. http://dx.doi.org/10.5194/acpd-7-2961-2007.
Full textAbstract:
Abstract. The reactivity of aromatic compounds is of great relevance to pure and applied chemical disciplines, yet existing methods for estimating gas-phase rate coefficients for their reactions with free radicals lack accuracy and universality. Here a novel approach is taken, whereby strong relationships between rate coefficients of aromatic hydrocarbons and a Randić-type topological index are investigated, optimized and developed into a method which requires no specialist software or computing power. Measured gas-phase rate coefficients for the reaction of aromatic hydrocarbons with OH radicals were correlated with a calculated Randić-type index, and optimized by including a term for side chain length. Although this method is exclusively for use with hydrocarbons, it is more diverse than any single existing methodology since it incorporates alkenylbenzenes into correlations, and can be extended towards other radical species such as O(3P) (and tentatively NO3, H and Cl). A comparison (with species common to both techniques) is made between the topological approach advocated here and a popular approach based on electrophilic subsituent constants, where it compares favourably. A modelling study was carried out to assess the impact of using estimated rate coefficients as opposed to measured data in an atmospheric model. The difference in model output was negligible for a range of NOx concentrations, which implies that this method has utility in complex chemical models. Strong relationships (e.g.~for OH, R2 = 0.96) between seemingly diverse compounds including benzene, multisubstituted benzenes with saturated, unsaturated, aliphatic and cyclic substitutions and the nonbenzenoid aromatic, azulene suggests that the Randić-type index presented here represents a new and effective way of describing aromatic reactivity, based on a quantitative structure-activity relationship (QSAR).
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Afanasjeva, Natalia, Andrea González-Córdoba, and Manuel Palencia. "Mechanistic Approach to Thermal Production of New Materials from Asphaltenes of Castilla Crude Oil." Processes 8, no. 12 (December 12, 2020): 1644. http://dx.doi.org/10.3390/pr8121644.
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Asphaltenes are compounds present in crude oils that influence their rheology, raising problems related to the extraction, transport, and refining. This work centered on the chemical and structural changes of the asphaltenes from the heavy Colombian Castilla crude oil during pyrolysis between 330 and 450 °C. Also, the development of new strategies to apply these macromolecules, and the possible use of the cracking products as a source of new materials were analyzed. The obtained products (coke, liquid, and gas) were collected and evaluated through the techniques of proton and carbon-13 nuclear magnetic resonance (1H and 13C NMR), elemental composition, Fourier-transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), saturates, aromatics, resins, and asphaltenes (SARA) analysis, and gas chromatography–mass spectrometry (GC-MS). A comparison of the applied methods showed that the asphaltene molecules increased the average size of their aromatic sheets, lost their aliphatic chains, condensed their aromatic groups, and increased their degree of unsaturation during pyrolysis. In the liquid products were identified alkylbenzenes, n-alkanes C9–C30, and n-alkenes. Moreover, the gaseous products included methane, ethane, propane, and pentane. An approach of the structural chain reaction was used to define the possible asphaltenes chemical structures before and after pyrolysis. In conclusion, this type of thermal process can be used as an easy route to attain new materials associated with specific structural units from the asphaltenes.
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KUZMENKO, S. M., E. O. SPORYAGIN, O. M. KUZMENKO, and A. YA PUZENKO. "SYNTHESIS AND PROPERTIES OF OLIGODIURETANEDIOLS BASED ON A MIXTURE OF (2,4–2,6) TOLUILENDIISOCYANATE." Polymer journal 43, no. 3 (September 20, 2021): 198–203. http://dx.doi.org/10.15407/polymerj.43.03.198.
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The paper describes the synthesis, the reaction of a mixture of isomers (2,4–2,6) of toluilendiisocyanate with a double molar excess of aliphatic individual or oligomeric diols, a number of previously unknown oligodiuretanediols and their physicochemical constants. It is shown that with an increase in the synthesis temperature from 50 to 70 °C, the reaction time to complete depletion in the mixture of free NCO-groups decreases from 8–9 hours to 3–4 hours. The reaction temperature of 70–2 °С should be considered optimal, because at higher temperatures side reactions of free NCO-groups with already formed urethane ones are possible. Because the presence of even a small amount of moisture in the diols can provoke side effects during the urethane formation reaction, all of the above diols were dried from the adsorbed moisture by azeotropic distillation with toluene before use in the reaction. Since the final products are even at the synthesis temperature (68–70 °C) viscous liquids, and there are difficulties with the homogenization of the reaction mass during synthesis, and when unloading the finished product from the reaction plant, in all cases, the synthesis was performed in solution cyclohexanone by 50 % by weight of the final product. Control of the reaction was performed by changing the % wt. free NCO-groups in time. The reaction was considered complete if the measured % wt. free NCO-groups in the reaction mixture for at least one hour twice showed zero. The isolated oligodiuretanediols range from solid at room temperature to very viscous products, which significantly depends on the molecular weight of the diol used in the reaction (ie the concentration of urethane groups formed). They are homogeneous, transparent compounds that are readily soluble in esters, ethers, aromatic and halide-containing, aprotic solvents, ketones, poorly or completely insoluble in aliphatic saturated hydrocarbons. The structure of the synthesized oligomeric products is confirmed by functional analysis, IR–spectra. In the IR-spectra of each of the synthesized oligodiuretanediols there are no absorption bands in the region of 2270 cm-1, which confirms the complete completion of the reaction of urethane formation according to the scheme. At the same time, the absorption bands in the region of 3450 cm-1, 1720 cm-1, 1540 cm-1 are fixed, which are characteristic of the presence of urethane groups in the structure of the target products. As the chain length of the diol component –R– increases in the target product (which synchronously leads to an increase in molecular weight), the intensity of these absorption bands decreases, which is associated with a decrease in the concentration of formed urethane groups in the structure of oligodiuretanediols. The refractive index also decreases synchronously. Synthesized series of oligodiuretanediols can be used for synthesis on its basis of other classes of oligomers with the simultaneous presence in the structure of urethane groups. The ability of such compounds to be soluble in solvents of different nature has been studied, which provides information for the directions of their further use (varnishes, enamels, primers).
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Gaisberger, Birgit, and Sonja Solar. "Demethoxylation and hydroxylation of methoxy- and hydroxybenzoic acids by OH-radicals. Processes of potential importance for food irradiation." Canadian Journal of Chemistry 79, no. 4 (April 1, 2001): 394–404. http://dx.doi.org/10.1139/v01-058.
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The hydroxylation process for methoxy- and hydroxy-benzoic acids (MBA, HBA) induced by γ-radiation is compared. 2-, 3-, and 4-methoxybenzoic acid as well as 3-hydroxybenzoic acid have been irradiated in N2O and aerated solutions up to 1.5 kGy. The products were analyzed by HPLC. The results for 2- and 4-HBA have been taken from literature data. The OH·-adduct distribution is generally the same for the hydroxy- as well as for the methoxy-benzoic acid isomers. With both 4-HBA and 4-MBA more than 65% C3-adducts and about 15% C4-adducts are formed, which could be proved by their reactions with K3Fe(CN)6. Oxidation of the nonipso-adducts of 3-HBA and 3-MBA results in 84 and 87% of the corresponding phenols. Whereas in N2O-saturated solutions only part of the OH·-radicals leads to substrate decomposition, in the presence of air, the degradation of both kinds of compounds is equivalent to [OH·]. The nonipso OH·-adducts of the HBAs are converted into 6877% hydroxylation products. With the MBAs, the hydroxylation process is [Formula: see text] 10%. This is attributed to different decay pathways of the peroxyl radicals, intermediates formed by O2 addition to the OH·-adducts. The hydroxyperoxycyclohexadienyl radicals of the HBAs decay mainly by HO2· elimination to the corresponding phenols, those of the MBAs decay predominantly by fragmentation of the benzene ring, yielding to nonidentified aliphatic products. The replacement of -OCH3 by -OH is practically not influenced by the presence of oxygen, it increases in the sequence 3-MBA < 4-MBA < 2-MBA. For 2-MBA, yields of more than 15% are obtained. Both processes, hydroxylation as well as demethoxylation, might be of importance for the recognition of radiolytical changes in foodstuff.Key words: γ-radiolysis, methoxybenzoic acids, hydroxybenzoic acids, phenolic acids, food components, reaction mechanisms, product analysis, HPLC analysis.