Academic literature on the topic 'Flavonoli'
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Journal articles on the topic "Flavonoli"
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Marchi, D., D. Lanati, G. Mazza, and P. Cascio. "Composizione in antociani e flavonoli di vini prodotti nel territorio svizzero." BIO Web of Conferences 15 (2019): 02012. http://dx.doi.org/10.1051/bioconf/20191502012.
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In questa nota sono presentati i risultati delle determinazioni del profilo degli antociani e dei flavonoli di vini prodotti con uve di alcune varietà a frutto colorato prodotte a Nord della Svizzera, nel cantone di Schaffhausen , nella regione di Klettgau. I vini sono stati ottenuti da uve delle varietà di Vitis vinifera Cabernet Dorsa, Gamaret, Dornfelder, Acolon e di un incrocio interspecifico Sylvaner × Müller Thurgau × Chambourcin (Regent). Il profilo degli antociani dei vini delle varietà di Vitis vinifera studiate è risultato a netta prevalenza di molecole trisostituite all'anello laterale (soprattutto malvidina-3-glucoside e suoi derivati acilati). Il vino Regent si è rivelato ricco di antociani 3,5-diglucosidi (soprattutto della malvidina) che hanno superato in proporzione i monoglucosidi. Di rilevante interesse è risultato il profilo dei flavonoli per la presenza nei vini, appena dopo la fine della fermentazione alcolica, di quercetina aglicone, di solito assente nell'uva. I vini Acolon e Regent sono risultati i più ricchi di quercetina aglicone. L'origine della quercetina aglicone nei vini esaminati in questo lavoro è stata attribuita all'idrolisi che le forme glicosilate di questo flavonolo hanno subito, probabilmente per via enzimatica, già durante la macerazione fermentativa.
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Marchi, D., D. Lanati, P. Cascio, and M. Giacomo. "Influenza della sfogliatura sulla sintesi della quercetina in Sangiovese. Ulteriori acquisizioni sui precipitati di quercetina nei vini." BIO Web of Conferences 15 (2019): 02010. http://dx.doi.org/10.1051/bioconf/20191502010.
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Allo scopo di approfondire i fattori che portano ad un accumulo elevato dei flavonoli e in particolare dei glicosidi della quercetina nell'uva abbiamo valutato in campo l'influenza della defogliazione precoce e all'invaiatura e di altre variabili viticole sulla sintesi di questi composti. Nello stesso tempo abbiamo studiato l'influenza della refrigerazione del vino e della formazione di complessi con altre sostanze presenti nel vino sulla solubilità della quercetina aglicone. I risultati ottenuti hanno confermato che: i) la defogliazione, in particolare quella precoce, inducono un incremento della sintesi dei flavonoli nell'uva, ii) la quercetina aglicone forma complessi, presumibilmente con gli antociani monomeri e con certe classi di pigmenti polimeri, con un incremento sensibile della sua solubilità, iii) la refrigerazione dei vini in cui la quercetina aglicone è presente sopra la sua soglia di solubilità porta alla sua precipitazione.
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Lewis, David, Marie Bradley, Stephen Bloor, Ewald Swinny, Simon Deroles, Chris Winefield, and Kevin Davies. "Altering expression of the flavonoid 3′-hydroxylase gene modified flavonol ratios and pollen germination in transgenic Mitchell petunia plants." Functional Plant Biology 33, no. 12 (2006): 1141. http://dx.doi.org/10.1071/fp06181.
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Antisense technology was successfully used to reduce flavonoid 3′-hydroxylase (F3′H) gene expression and enzyme activity and to promote the accumulation of monohydroxylated flavonols in petunia flower tissue. The hydroxylation pattern of specific flavonoid groups is a target for modification because of the possible associated changes in a range of factors including colour, stress tolerance and reproductive viability. Petunia (cv. Mitchell) plants were transformed to express in the antisense orientation the sequences encoding the F3′H (asF3′H). Transformants showed a range of responses, in terms of the level of endogenous F3′H gene expression and the relative proportion of the monohydroxylated flavonol (kaempferol) glycosides that accumulated. Kaempferol glycosides increased from 7% of the total flavonols in flower limb tissue of the wild type plants, to 45% in the flower limb tissue of line 114, the transgenic line that also showed the greatest decrease in F3′H expression in flower tissue. In leaf tissue, the trend was for a decrease in total flavonol concentration, with the relative proportion of kaempferol glycosides varying from ~40 to 80% of the total flavonols. The changes in leaf tissue were not consistent with the changes observed in flower tissue of the same lines. Endogenous F3′H activity in flower limb tissue was not completely shut down, although an 80% decrease in enzyme activity was recorded for line 114. The residual F3′H activity was still sufficient that quercetin glycosides remained as the major flavonol form. Alteration of F3′H activity appears to have affected overall flavonoid biosynthesis. A decrease in total flavonol concentration was observed in leaf tissue and two other flavonoid biosynthetic genes were down-regulated. No morphological changes were observed in the transgenic plants; however, up to a 60% decrease in pollen germination was observed in line 13. Thus, the relatively small change in flavonoid biosynthesis induced by the asF3′H transgene, correlated with several other effects beyond just the specific biosynthetic step regulated by this enzyme.
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Joshi, Kunjani. "Leaf Flavonoid Patterns in the Species of Stemonoporus (Dipterocarpaceae) and Their Taxonomic Significance." Journal of Natural History Museum 24 (October 9, 2009): 146–55. http://dx.doi.org/10.3126/jnhm.v24i1.2291.
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During the chemotaxonomic study of 16 species of Stemonoporus, three flavonoid aglycones (flavonol quercetin, flavonol kaempferol and flavone apigenin) and glycosides (quercetin 3- glucoside, quercetin 3-rutinoside and apigenin 5-glucoside) were isolated while flavonol myricetin, flavone luteolin and proanthcyanidin were not detected in any of the species surveyed. The isolated flavonoids can be used as chemotaxonomic markers. The species of Stemonoporus can be regarded as advanced in flavonoid pattern because of the absence of myricetin and loss of proanthocyanidins. The data of the flavonoid patterns and the outcome of cluster analysis are taxonomically useful to resolve the controversies over the systematic arrangement of the species and suggest the need for a revision of classification of the genus Stemonoporus. Key words: Dipterocarpaceae; Flavonols; Chemotaxonomy; Cluster analysis. Journal of Natural History MuseumVol. 24, 2009Page: 146-155
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Ivey, Kerry L., Joshua R. Lewis, Richard L. Prince, and Jonathan M. Hodgson. "Tea and non-tea flavonol intakes in relation to atherosclerotic vascular disease mortality in older women." British Journal of Nutrition 110, no. 9 (April 29, 2013): 1648–55. http://dx.doi.org/10.1017/s0007114513000780.
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Epidemiological studies have indicated that dietary flavonoids generally, and flavonols specifically, may contribute to cardiovascular health. Tea consumption, which is often the main dietary source of flavonoids and flavonols, is associated with a reduced risk of cardiovascular outcomes. The primary objective of the present study was to explore the association of the habitual intake of flavonols from tea and non-tea sources with the risk of atherosclerotic vascular disease mortality in a population of elderly women. A total of 1063 women, aged over 75 years, were randomly selected from ambulant Caucasian women living in Perth, Western Australia. Flavonoid consumption was assessed using the US Department of Agriculture Flavonoid, Flavone and Proanthocyanidin databases. Atherosclerotic vascular disease mortality was assessed over 5 years of follow-up through the Western Australian Data Linkage System. During the follow-up, sixty-four women died from atherosclerotic vascular disease. Women in the highest compared with the lowest tertile of flavonol intake had a lower risk of atherosclerotic vascular disease death (OR 0·27, 95 % CI 0·13, 0·59; P≤ 0·01 for trend in multivariate-adjusted models). Similar relationships were observed for flavonol intake derived from both tea (OR 0·38, 95 % CI 0·18, 0·79; P< 0·01) and non-tea (OR 0·41, 95 % CI 0·20, 0·85; P= 0·05) sources. Tea was the main contributor to flavonol intake (65 %), and the intakes of flavonols from tea and non-tea sources were not significantly correlated. In conclusion, increased consumption of flavonols was independently associated with a lower risk of atherosclerotic vascular disease mortality. Both tea and non-tea sources of flavonols were independently associated with this benefit.
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Lumbessy, Mirna, Jemmy Abidjulu, and Jessy J. E. Paendong. "Uji Total Flavonoid Pada Beberapa Tanaman Obat Tradisonal Di Desa Waitina Kecamatan Mangoli Timur Kabupaten Kepulauan Sula Provinsi Maluku Utara." Jurnal MIPA 2, no. 1 (January 31, 2013): 50. http://dx.doi.org/10.35799/jm.2.1.2013.766.
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Penelitian ini bertujuan untuk menguji total kandungan flavonoid pada beberapa tanaman obat tradisional. Penentuan kandungan total flavonoid dilakukan dengan menggunakan metode etanol – HCl, sedangkan analisis flavonoid menggunakan Metode spektrofotometeyr UV-VIS . Hasil yang diperoleh menunjukan kandungan total flavonoid pada tanaman ketepeng cina (Cassia alata L) sebesar 26.8633 mg/mL , iler (Coleus scutellariodes L Benth) sebesar 14.425 mg/mL , rumput teki (Cyperus rotundus L) sebesar 6.505 mg/mL, pegagan (Centella asiatica) sebesar 3.816 mg/mL, rumput mutiara (Oldenlandia corymbosa) sebesar 2.686 mg/mL dan waru (Hibiscus tiliaceus L) sebesar 1.425 mg/mL. Kandungan total flavonoid tertinggi terdapat pada daun ketepeng sebesar 26.863 mg/mL, sedangkan kandungan flavonoid terendah terdapat pada daun waru sebesar 1.425 mg/mL. Analisis flavonoid dilakukan pada 𝜆 = 200 - 400 nm dan 𝜆maks = 205 nm. Hasil analisis flavonoid menunjukkan bahwa [A] daun iler panjang gelombang maksimum yaitu 205 nm dan (pita I) 300 nm dan (pita II) 250 nm dengan absorbansi 0.242 positif mengandung flavonol. [B] daun rumput mutiara panjang gelombang maksimum 205 nm dan dapat dilihat pada (pita I) 305 nm dan (pita II) 260 nm dengan absorbansi 0.023 positif mengandung flavonol. [C]) daun ketepeng panjang gelombang maksimum 205 nm dan dapat dilihat pada (pita I) 330 nm dan (pita II) 276 nm dengan absorbansi 0.167 positif mengandung flavonol. [D]) daun pegagan panjang gelombang maksmum 205 nm dan dapat dilihat pada (pita I) 310 nm dan (pita II) 265 nm dengan absorbansi 0.047 positif mengandung flavonol. (E) rumput teki hanya terdapat (I pita) yaitu 295 nm dengan absorbansi 0.029 positif mengandung flavon. (F) Begitupun dengan daun waru hanya terdapat (I pita) yaitu 290 nm dengan absorbansi 0.036 positif mengandung flavon. Dapat disimpulkan bahwa berdasarkan uji kualitatif tanaman iler, ketepeng, rumput mutiara, rumput teki dan pegagan mengandung flavonoid kecuali tanaman waru tidak terdeteksi kandungan flavonoidnya.This studyaims to examine the total flavonoid contentin some traditional medicinal plants. Determination of total flavonoid content swere determined using ethanol-HCl, where as flavonoid analysis was analysed by spectrophotometry UV-VIS.The results showed the total flavonoid contentin Ketepeng China plant (Cassia alataL.) was 26.863 mg/ml, Iler plant (Coleus scutellariodes L. Benth) was 14.2464 mg/ml, nut-grass (Cyperus rotundus L.) was 6.505 mg/ml; Pegagan (Centella asiatica) was 3.816 mg/ml; pearl grass (Oldenlandia corymbosa) was 2.686 mg/ml, and Waru (Hibiscus tiliaceus L.) was 1.425 mg/ml. The highest total flavonoid was found in ketepeng(26.8633mg/ml), whereas the lowest was found in waru (1.4246 mg/ml). Flavonoid analysis was performed using a spectrometer with a wavelength (λ) of 200-400 nm, with λmax = 205 nm. Flavonoid analysis using a spectrophotometer, amon others showed that: (1) The maximum wavelength of Iler leaf was 205 nm and can be see non the Band I 300 nm and Band II 250 nm, with 0.242 absorbance. This indicates that this isolate was positive for flavonols; (2) Maximum wavelength of pearl leaf was 205 nm and can be see non the Band I 305 nm and Band II 260 nm, with 0.023 absorbance. This indicates that this isolate was positive for flavonols; (3) Maximum wavelength of ketepeng leaf was 205 nm and can be see non the Band I 330 nm and Band II 276 nm, with 0.167 absorbance. This indicates that this isolate was positive for flavonols; (4) Maximum wavelength of pegagan leaf was 205 nm and can be see non the Band I 310 nm and Band II 265 nm, with 0.047 absorbance. This indicates that this isolate was positive for flavonols; (5) nut-grass had only 1 band, namely 295 nm with absorbance 0.029. This indcates that this isolate was positive for flavons; (6) waru leaf had also only 1 band, namely 290 nm with absorbance 0.036. This this isolate was positive for flavons.
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Satheesh Kumar D, Shailendra Kumar, and Ravichandran S. "In vitro antidiabetic evaluation of nanoparticles encompass dual bioflavonoid." International Journal of Research in Phytochemistry and Pharmacology 8, no. 1 (July 16, 2020): 1–6. http://dx.doi.org/10.26452/ijrpp.v8i1.1224.
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The flavonoids which are widely spread in plants. It can be categorized as flavonols, flavonols, flavanones, flavones, anthocyanidin and isoflavones. Apigenin and Hesperidin account these three flavonoids used a significant proportion of flavonol intake in the diet as a functional food. Among all other flavonoids, Apigenin has many health cares and disease-prevention benefits. Polymer-based formulations, such as nanoemulsions and solid lipid nanoparticles, have been developed to increase the therapeutic efficacy of flavonoids. New drug delivery systems such as Dual Loaded Flavono Nanoparticulate System (DLFNPs) have not yet been studied with Apigenin and Hesperidin. In the present study, dual loaded flavonol nanoparticulate systems have been developed for oral delivery of Apigenin to enhance its antioxidant and antidiabetic activities. The fabrication of Dual Loaded Flavono Nanoparticles by Nano precipitation technique. Prepared Dual Loaded Flavono polymeric nanoparticles were subjected to characterization and various pharmacological activities. In vitro results revealed that the Alfa amylase percentage of inhibition 33.5% for Nanoparticles Encompass Dual Bioflavonoid by the indication pet ether extracts have lesser activity. This work will be useful for diabetic research workers to be found in the new chemical entity for the treatment of DM and its associated diseases.
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Maslov Bandić, Luna, Milena Jenić, and Boris Duralija. "Bioaktivni spojevi u plodu, listu i sjemenci maline (Rubus idaeus L.)." Glasnik zaštite bilja 43, no. 5 (October 29, 2020): 50–55. http://dx.doi.org/10.31727/gzb.43.5.6.
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Malina (Rubus idaeus L.) jedna je od voćnih vrsta koje su bogate raznolikim kemijskim spojevima kao što su vitamini, minerali i polifenoli. Polifenoli utječu na senzorna i nutritivna svojstva biljke. Listovi i sjemenke maline, koje su većinom nusprodukt proizvodnje imaju značajan sadržaj polifenola, te bi se zajedno s plodovima mogli više koristiti u ljudskoj prehrani kao alternativni izvor bioaktivnih spojeva. U ovom radu određivani su polifenolni spojevi, te je utvrđen sadržaj flavonoida, antocijana i ukupnih fenola u plodu, sjemenci i listu maline sorte 'Himbo Top'. Najveći maseni udio polifenola imale su sjemenke maline, od kojih je izmjereno najviše flavonoida (2853,03 mg/100 g svježeg uzorka) i ukupnih fenola (2369,44 mg/100 g svježeg ploda), a najmanji maseni udio polifenola kod maline imali su plodovi. Također, određen je i antioksidacijski kapacitet pomoću DPPH i ABTS metode, te nisu utvrđene značajne razlike u antioksidacijskom kapacitetu između ploda, lista i sjemenke. Pomoću LC-MS metode identificirani su pojedinačni antocijani i flavonoli u plodu maline.
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Sun, Caihong, Hui Wang, Dong Wang, Yanping Chen, Yan Zhao, and Wei Xia. "Using an FFQ to assess intakes of dietary flavonols and flavones among female adolescents in the Suihua area of northern China." Public Health Nutrition 18, no. 4 (May 6, 2014): 632–39. http://dx.doi.org/10.1017/s1368980014000780.
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AbstractObjectiveThe present study aimed to (i) evaluate the reproducibility and validity of a designed FFQ, (ii) apply the FFQ for estimating the dietary intakes of four flavonols and two flavones in female adolescents and (iii) explain their major dietary sources.DesignThe reproducibility between the first and second FFQ administrations (1 year interval) was estimated using the intra-class correlation coefficient. The validity of the first FFQ relative to the average of four three-day 24 h dietary recalls (24-HR) from four seasons was assessed using the Spearman correlation coefficient. Using a flavonoid content database, the individual flavonol and flavone intakes were calculated and the major food sources were estimated.SettingMiddle school in Suihua area of Heilongjiang Province, northern China.SubjectsFemale adolescents (n 887) aged 12–18 years.ResultsBetter reproducibility and validity were obtained in the present study. The flavonol and flavone intakes were 16·29 and 4·31 mg/d, respectively. Quercetin and kaempferol were the major contributors (26·8 % and 23·7 %, respectively) to the total intake of flavonols and flavones. The main food sources of flavonols and flavones were apples (14·1 %), followed by potatoes (7·5 %), lettuce (7·3 %) and oranges (7·3 %).ConclusionsThe dietary flavonol and flavone intakes among female adolescents in northern China were similar to those reported in several countries, but significant differences were observed in the food sources ascribed to the geographical location and dietary characteristics.
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Nikolova, M., and S. Ivancheva. "Distribution of Surface Flavonoids in Bulgarian Plants." Natural Product Communications 1, no. 11 (November 2006): 1934578X0600101. http://dx.doi.org/10.1177/1934578x0600101119.
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The review describes the distribution of surface flavonoids in Bulgarian plants. More than 100 species of Asteraceae, Lamiaceae, Scrophulariaceae, Geraniaceae and other families have been checked for external flavonoid aglycones. The flavonoid profiles of Asteraceae species are composed of a wide array of flavones and flavonols, mainly based upon 6-substituted derivatives. Flavone aglycones are predominant in the exudates of Lamiaceae species. Apigenin, luteolin and their derivatives were most commonly found in the studied species of Scropulariaceae and Lamiaceae. It has been shown that species of Geraniaceae, Ranunculaceae, and Solanaceae contain flavonoids of the flavonol class as surface constituents. Surface distributed flavonoids appear to have been well studied and useful for chemotaxonomy. If there is not too much infraspecific variation, flavonoid profiles can be used as taxonomic characters to distinguish species. Correlations between external flavonoid formation and local environment are apparent.
Dissertations / Theses on the topic "Flavonoli"
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McIntosh, Cecilia A. "Position-Specific Flavonoid Glucosyltransferases: Structure and Functional Analysis of Grapefruit Flavonol-Specific 3-O-GT." Digital Commons @ East Tennessee State University, 2014. https://dc.etsu.edu/etsu-works/367.
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Owens, Daniel Kenneth. "Examination of 2-Oxoglutarate Dependant Dioxygenases Leading to the Production of Flavonols in Arabidopsis thaliana." Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/29144.
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The flavonols are a varied and abundant sub-class of flavonoids that are associated with a number of essential physiological functions in plants and pharmacological activities in animals. The 2-oxoglutarate-dependant dioxygenases(2-ODDs), flavonol synthase (FLS) and flavanone 3-hydroxylase (F3H), are essential for flavonol synthesis. The primary goal of this study has been to gain a deeper understanding of the biochemistry of these enzymes in Arabidopsis.
To accomplish this goal, an activity assay employing recombinant protein expression and HPLC as a detection system was developed for F3H and adapted for use with FLS. The assay was employed to establish the biochemical parameters of F3H from Arabidopsis, and to further characterize the F3H mutant allele, tt6(87). Enzymatic activity was demonstrated for F3H enzymes from Ipomoea alba (moonflower), Ipomoea purpurea (common morning glory), Citrus sinensis (sweet orange), and Malus X domestica (newton apple), each of which had previously been identified solely based on sequence homology.
Arabidopsis contains six genes with high similarity to FLS from other plant species; however, all other central flavonoid pathway enzymes in Arabidopsis are encoded by single genes. The hypothesis that differential expression of FLS isozymes with varying substrate specificities is responsible for observed tissue-specific differences in flavonol accumulation was tested. Sequence analysis revealed that AtFLS2, 4 and 6 contain premature stop codons that eliminate residues essential for enzyme activity. AtFLS1 was found to have a strong preference for dihydrokaempferol as a substrate. However, no enzyme activity was observed for AtFLS3 or AtFLS5 with a number of different substrates under a variety of reaction conditions. To identify structural elements that may contribute to the observed differences in biochemical activity, homology models for each of the isoforms were generated utilizing Arabidopsis anthocyanin synthase (ANS) as a template. A domain at the N-terminus of AtFLS1 that is missing in the other isozymes was insufficient to convey activity to an AtFLS1/5 chimera. These findings suggest a single catalytically-active form of FLS exists in Arabidopsis. The possibility that the apparently expressed but non-catalytic proteins, AtFLS2, 3, and 5, serve noncatalytic roles in flavonol production were explored by yeast 2-hybrid analysis.Ph. D.
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Reinboth, Marianne. "Bioverfügbarkeit des Flavonols Quercetin beim Hund." Doctoral thesis, Universitätsbibliothek Leipzig, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-62483.
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6 Zusammenfassung Marianne Reinboth Bioverfügbarkeit des Flavonols Quercetin beim Hund Veterinär-Physiologisches Institut der Veterinärmedizinischen Fakultät der Universität Leipzig Eingereicht im Juni 2010 79 Seiten, 20 Abbildungen, 6 Tabellen, 211 Literaturangaben, 1 Anhang Schlüsselwörter: Quercetin, Bioverfügbarkeit, Hund, absolute Bioverfügbarkeit, Isoquercitrin, Rutin, Flavonole Für das pflanzliche Flavonol Quercetin werden vielfältige gesundheitsfördernde Wirkungen postuliert, so auch bei Hunden. Über die Bioverfügbarkeit des Flavonols bei dieser Spezies liegen bislang jedoch keinerlei Daten vor. Daher hatte diese Arbeit das Ziel, Bioverfügbarkeit und pharmakokinetische Parameter von Quercetin und wichtigen Quercetinglycosiden bei Hunden nach deren Verabreichung mit einer Testmahlzeit in einer praxisrelevanten Dosierung von 10 mg/kg Körpermasse zu untersuchen. Dazu erhielten 9 adulte Beagles beiderlei Geschlechts das zuckerfreie \"Aglycon\" Quercetin bzw. seine Glycoside Isoquercitrin (Quercetin-3-O-Glucosid) und Rutin (Quercetin-3-O-Glucorhamnosid) in jeweils äquimolarer Dosierung in einer Testmahlzeit verabreicht. Anschließend wurden Blutproben über einen Zeitraum von bis zu 72 Stunden entnommen und mittels HPLC die Konzentrations-Zeitverläufe der Metaboliten im Blutplasma, die Bioverfügbarkeit sowie weitere pharmakokinetische Parameter bestimmt. Weiterhin wurde die absolute Bioverfügbarkeit von Quercetin aus dem Vergleich einer oralen mit einer intravenösen Applikation bestimmt. Der weitaus größte Teil der Plasmametaboliten von Quercetin sowie seiner beiden Glycoside bestand aus glucuronidierten bzw. sulfatierten Quercetinkonjugaten. Nicht konjugiertes Quercetin-Aglycon kam nur in einem Anteil von etwa 20 % vor. Neben Quercetin machten seine Metaboliten Isorhamnetin und Kämpferol weniger als 10 % aller im Plasma zirkulierenden Flavonole aus. Die absolute Bioverfügbarkeit von Quercetin betrug nur etwa 4 %. Die relative Bioverfügbarkeit aus dem 3-O-Glucosid Isoquercitrin war mehr als doppelt so hoch wie aus dem Aglycon, die maximalen Plasmaspiegel lagen aber auch hier unter 1 µmol/l. Sowohl nach Aufnahme von Quercetin als auch nach Isoquercitrin kam es zu einer relativ schnellen Absorption aus dem Dünndarm mit einem ersten Plasmapeak ungefähr eine Stunde nach der Ingestion. Vier Stunden nach Aufnahme der beiden Flavonole trat ein zweiter Plasmapeak auf, der in der Regel höher als der erste ausfiel. Dies deutet auf einen enterohepatischen Kreislauf der über die Galle ausgeschiedenen Metaboliten hin. Nach Aufnahme von Rutin kam es zu einer verzögerten Absorption, da eine Deglycosylierung durch bakterielle Glycosidasen im Dickdarm Voraussetzung für die Absorption des Flavonols ist. Maximale Plasmakonzentrationen wurden im Mittel erst 11 Stunden nach Ingestion dieses Glycosids erreicht. Die maximalen Plasmakonzentra-tionen nach Rutin waren geringer als nach Quercetin oder Isoquercitrin, jedoch war die mittlere Verweildauer der Plasmametaboliten mit 18 Stunden auch wesentlich länger. Im Unterschied zu anderen Spezies war die relative Bioverfügbarkeit von Rutin gegenüber Quercetin nicht verringert. Obwohl Rutin eine relativ gute Quercetinquelle für Hunde zu sein scheint, muss bei der Einschätzung möglicher In-vivo-Wirkungen die relativ geringe Bioverfügbarkeit sowie die intensive Metabolisierung seines Aglycons Quercetin berücksichtigt werden7 Summary Marianne Reinboth Bioavailability of the Flavonol Quercetin in Dogs Institute of Physiology of the Faculty of Veterinary Medicine, University of Leipzig Submitted in June 2010 79 pages, 20 figures, 6 tables, 211 references, 1 appendix Keywords: quercetin, bioavailability, dog, absolute bioavailability, isoquercitrin, rutin, flavonols The plant flavonol quercetin is supposed to exert multiple health-related effects in dogs. To date no information on its bioavailability in this particular species is avai-lable. This study intended to investigate bioavailability and pharmacokinetics of quercetin and certain quercetin glycosides in dogs after ingestion of a test meal sup-plemented with a quercetin dose equivalent to 10 mg/kg body weight. Nine adult beagle dogs of both sexes received the aglycon quercetin (sugarfree) or its glycosides isoquercitrin (quercetin-3-O-glucoside) and rutin (quercetin-3-O-glucorhamnoside) in equimolar amounts together with a test meal. Blood samples were taken over a period of up to 72 hours; bioavailability and pharmacokinetics were calculated from the HPLC-derived plasmaconcentration-time-curves. Absolute bioavailability was calculated by comparing an oral to an intravenous administration of quercetin. The majority of analysed plasma metabolites were glucuronidated and sulfated con-jugates of quercetin. Non-conjugated quercetin aglycon comprised only 20 %. Be-sides quercetin, its metabolites isorhamnetin and kaempferol made up less than 10 % of all circulating metabolites. The absolute bioavailability of quercetin was only 4 %. The relative bioavailability of quercetin from isoquercitrin was more than twice as high than from the aglycon, but even there maximal plasma concentrations were generally less than 1 μmol/l. Absorption from the small intestine was rather fast with a first plasma peak after 1 hour after ingestion of quercetin or isoquercitrin. A second, generally higher plasma peak occurred 4 hours after ingestion. This suggests an in-tensive enterohepatic recycling of biliary secreted metabolites. Absorption was significantly delayed after ingestion of rutin due to the necessity of bacterial deglycosilation in the large intestine. Plasma concentrations peaked only after 11 hours. Plasma concentrations after rutin were lower than after quercetin or isoquercitrin, but mean residence time of plasma metabolites was as long as 18 hours after rutin ingestion. Consequently, a once daily feeding of dogs with rutin might lead to relatively constant plasma metabolite concentrations. In contrast to other species, bioavailability from rutin was not smaller than that from quercetin. Although rutin seems to be a relative good quercetin source for dogs, estimations about potential in-vivo-effects of quercetin have to take into consideration its low bioavailabilty and intensive metabolism
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Costa, Patricia Miranda da. "Triterpenos, saponinas e flavono?des de L. arianeae (Chrysobalanaceae) e Eschweilera longipes (Lecythidaceae)." Universidade Federal Rural do Rio de Janeiro, 2003. https://tede.ufrrj.br/jspui/handle/jspui/1561.
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Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico
Solvent partition and chromatographic fractionation of metanolic extract from the leaves and wood of L. arianeae lead to the isolation of triterpenes, one carboidrate, saponin and flavonoid. 3b,6b,19a -trihydroxiursa-12-en- 28-oic acid, 3b,6b,24-trihydroxiursa-12-en- 28-oic acid, 3,5,7-trihydroxi-4?-metoxi,6-flavone-( sulfonate), 3b-hydroxiolean-12-en-28- ?ico acid, 3b-O-b-D-galactopiranosyl-(6?-1 para hydroxi benzoil)-ursa-12-en-28-oic acid, 1-metyl glycopiranosyl and mixture of two flavonoids. The 3,5,7-trihydroxi-4?-metoxi,6- flavone-(sulfonate) and 3b-O-b-D-galactopiranosyl-(6?-1 para hydroxi benzoil)-ursa-12-en- 28-oic acid are being descricted for the first time in the literature. The IR, 1H NMR, 13C NMR and MS spectra analysis was used for structural determination.
O fracionamento dos extratos das folhas e madeira de L. arianeae atrav?s de processo de parti??o com solventes e t?cnicas cromatogr?ficas conduziu ao isolamento dos ?cidos 3b,6b, 19a -triidroxiursan-12-eno-28-?ico, 3b,6b,24,19a-tetraidroxiursan-12-eno-28-?ico, 3b-hidroxiolean-12-eno-28-?ico, da 3,5,7-triidroxi, 4?-metoxi, 6-sulfonato, flavona, da 3b- O-b-D-galactopiranosil-(6?-p-hidroxi-benzo?la)-ursan-12-eno-28-?ico, da 1-metil glicose, e da mistura de flavon?ides. As estruturas das subst?ncias foram deduzidas atrav?s da an?lise dos espectros de IV, RMN de 1H e 13C, incluindo experimentos 2D e espectro de massas das subst?ncias naturais e dos derivados. Este ? o primeiro registro destes constituintes no g?nero Licania. A flavona e saponina est?o sendo descritos pela primeira vez na literatura. As folhas e as cascas da esp?cie E. longipes foram submetidas a extra??o com solventes org?nicos e os extratos foram fracionados atrav?s de parti??o e t?cnicas cromatogr?ficas. As fra??es reunidas foram submetidas a t?cnicas cromatogr?ficas e cristaliza??o. Esses processamentos conduziram ao isolamento dos ?cidos 1a,2b,3a,19a -tetraidroxiursan-12- eno-28-?ico, da saponina 3b-O-b-D-glicopiranosil-sitosterol e dos triterpenos fridelinol e 3b,24-diidroxifridelano. As estruturas das subst?ncias foram deduzidas atrav?s das t?cnicas citadas acima. Este ? o primeiro registro desta saponina no g?nero Eschweilera. O triterpeno 3b,24-diidroxifridelano foi descrito pela primeira vez na literatura (COSTA, P.M. & Carvalho, M. G., Annais da Academia Brasileira de Ci?ncias, 2003).
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Jailani, Fadhilah. "Absorption and metabolism of flavonols." Thesis, University of Leeds, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.634526.
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The consumption of flavonols, major sources of dietary flavonoids, have been linked to the reduction of risk factors for various chronic diseases. However, the bioavailability of flavonols would appear to be limited and not all compounds within the same subclass are absorbed with equal efficacy, thus compromising their nutritional relevance. The aim of this current study was to examine the absorption and metabolism of four major flavonols specifically quercetin, myricetin, kaempferol and galangin using both in vitro methods and healthy human volunteers to investigate how bioavailability was affected by the addition of other ingredients, specifically fat. Firstly, the enzymatic synthesis of flavonol metabolites was conducted using liver S9 homogenates, which demonstrated that all major flavonol aglycone generated several isomers of glucuronide or sulphate forms after the incubation period. The evidence for identification and characterisation of available authentic standards and synthesised flavonol metabolites using HPLC-DAD-MS-MS is presented. The success of this method was demonstrated through its application to assess the fate of flavonols in the cell culture transport experiments, which were examined using co-cultures of Caco-2 (enterocyte cell) and HT29-MTX (goblet cell) monolayers and the results partially substantiate that the absorption is most probably achieved by passive transport.
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De, Marchi Fabiola. "Studio dei metaboliti chimici dell'uva finalizzato a valutare le potenzialità enologiche, nutraceutiche ed industriali di alcune varietà di vite e nuovi approcci di metabolomica." Doctoral thesis, Università degli studi di Padova, 2014. http://hdl.handle.net/11577/3423516.
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Grape, wine and oenology by-products are rich in polyphenols and in particular flavonoids: flavonols, anthocyanins, flavanols and proanthocyanidins. Those molecules are plants secondary metabolites and may also contribute to the bitterness and astringency of grapes and wines. In recent years, epidemiological studies have revealed the great potential of polyphenols and flavonoids in human diet on protection against cancers, infections, their role in anti-aging and also against the development of several chronic diseases such as cardiovascular diseases (CVDs) or diabetes. Their role for human health is attributed mainly to their antioxidant, anti-inflammatory, antimicrobial activities. Therefore these bio-compounds could find promising applications in pharmaceutical, nutraceutical and food industries as active ingredients in supplements with antioxidant activity, value-added ingredients in fortified foods or as natural dyes and preservatives.
The aim of this research is to investigate the contents of chemical metabolites in several unique Vitis vinifera varieties and hybrids, and to examine their potential for oenological, nutraceutical and industrial applications. Modern spectrophotometry, chromatography and mass spectrometry (MALDI/MS, LC/MS, GC/MS) analytical techniques were applied in order to achieve the aims of the research.
Nine Vitis vinifera italian native grape varieties from Friuli Venezia Giulia and Veneto regions, were investigated for their enological potential, by studying the main classes of polyphenols and aroma compounds of grapes and their organoleptic wine characteristics.
In addition 32 hybrid varieties (21 red, 11 white) that belong to the CRA-VIT Grapevine Germplasm Collection located in Conegliano (TV) were studied to evaluate their nutraceutical and industrial potential.
The study of anthocyanins of red hybrids showed that some varieties (e.g. Seibel 8357) have rich content of pigments and are therefore attractive for the production of natural dyes that are used in the food and pharmaceutical industry. Moreover, some varieties (Bacò 1 and Seibel 10878) were also found interesting for their triglycerides content in grape seed oil with high linoleic acid content (up to 70%), which is essential fatty acid effective in reducing LDL cholesterol.
The nutraceutical potential of hybrid varieties was investigated by studying grape seed proanthocyanidins. Oligomeric and polymeric proanthocyanidins with different degree of galloylation were determined in grape seed extracts suggesting potential application of the extracts as antioxidants in nutraceutical products and also as oenological tannins.
Eventually, a new methodology was established for grape metabolome study based on High-Resolution Mass Spectrometry (HR-MS) analysis and the “suspect screening analysis” approach. This method was proved to be very effective due to the ability to identify hundreds of compounds in one single run and also individual classes of grape polyphenolsL’uva, il vino ed i sottoprodotti dell’industria enologica sono ricche fonti di polifenoli e flavonoidi, quali flavonoli, antociani, flavanoli e proantocianidine. Questi composti determinano le caratteristiche sensoriali delle uve e dei vini, come il colore, il sapore e l’astringenza. Numerosi studi epidemiologici hanno dimostrato che questi composti esercitano un’azione benefica sulla salute umana e proteggono dall’insorgere di patologie croniche e degenerative soprattutto a carico dell’apparato cardiovascolare, grazie alle loro proprietà antiossidanti, anticancro, antinfiammatorie ed antimicrobiche. Questi biocomponenti, una volta estratti dalle varie parti della pianta, possono trovare importanti applicazioni come principi attivi di supplementi farmaceutici con attività antiossidante, ingredienti a valore aggiunto in alimenti fortificati, coloranti e conservanti naturali per l’industria alimentare. Lo scopo della ricerca è quello di studiare, mediante le moderne tecniche analitiche di spettrofotometria, cromatografia e spettrometria di massa (MALDI/MS, LC/MS, GC/MS), i metaboliti nelle uve di alcune varietà di Vitis vinifera e di viti ibride ad oggi poco conosciute al fine di individuarne le potenzialità enologiche, nutraceutiche ed industriali. Sono state valutate le potenzialità enologiche di nove varietà di V. vinifera appartenenti a vitigni autoctoni del Friuli Venezia Giulia e del Veneto, attraverso lo studio delle principali classi di polifenoli e aromi delle uve e dei principali parametri chimici e profili organolettici dei vini. Inoltre, sono state studiate le uve di 32 varietà di viti ibride (21 rosse e 11 bianche) presenti nella collezione del Germoplasma viticolo del CRA-VIT al fine di valutarne le potenzialità per i loro impieghi industriali e nella nutraceutica. Lo studio degli antociani delle varietà ibride rosse ha evidenzato alcune varietà particolarmente ricche di pigmenti (es. il Seibel 8357) e quindi interessanti per la produzione di coloranti naturali che vengono impiegati in particolare nell’industria alimentare e farmaceutica. Lo studio dei trigliceridi dell’olio di vinaccioli delle uve ibride ha evidenziato che in generale queste varietà hanno un elevato contenuto di acido linoleico (superiore al 70%), un acido grasso essenziale avente la proprietà di diminuire i livelli di colesterolo LDL, ed alcune varietà particolarmente interessanti per la loro produttività (Bacò 1 e Seibel 10878). Le potenzialità nutraceutiche di queste varietà sono state investigate anche studiando le proantocianidine negli estratti di vinaccioli. Sono state determinate numerose proantocianidine oligomere e polimere aventi diversi gradi di galloilazione, utilizzabili, oltre che come preparati antiossidanti, anche come tannini enologici per la chiarifica di mosti e vini. Infine, è stato sviluppato un nuovo metodo per lo studio della metabolomica dell’uva mediante analisi di spettrometria di massa ad alta risoluzione (HR-MS) con un approccio di “suspect screening analysis”. Il metodo è risultato molto efficace, ed ha permesso l’identificazione di centinaia di metaboliti con una singola analisi, incluse diverse classi di polifenoli dell’uva
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Huber, Lisia Senger. "Flavinoides : identificação de fontes brasileiras e investigação dos fatores responsaveis pelas variações na composição." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/256158.
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Orientador: Delia B. Rodriguez-AmayaTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: Devido a crescente importância atribuída aos flavonóides nos últimos anos, decorrente de suas ações relacionadas à prevenção de doenças degenerativas, e aliada à carência de dados destes compostos em alimentos brasileiros, este estudo teve como objetivo determinar os teores de flavonóis e flavonas em alimentos consumidos no Brasil e avaliar alguns fatores que influenciam seus níveis nestes alimentos. Uma revisão bibliográfica é apresentada no Capítulo 1, na qual são descritos os principais efeitos benéficos à saúde, aspectos analíticos e fatores que influenciam os teores de flavonóides em alimentos. Estes compostos com ação benéfica à saúde, atuam como antioxidantes, inibidores da proliferação celular, antiestrogênicos e mediadores intracelulares, exercendo proteção principalmente contra câncer e doenças cardiovasculares. A determinação desses compostos normalmente é feita utilizando-se cromatografia líquida de alta eficiência com detector de arranjo de diodos. Os níveis de flavonóides em alimentos podem ser influenciados por vários fatores, como estação do ano, preparo e processamento de alimentos. O Capítulo 2 descreve o desenvolvimento e validação da metodologia analítica para determinação de flavonóis e flavonas em hortaliças. Utilizando-se Delineamento Composto Central Rotacional, obtiveram-se as melhores condições para extração e hidrólise dos flavonóides encontrados na natureza na forma glicosídica, a suas respectivas agliconas. Essas condições foram: 1,0M de HCl por 6 horas para espinafre e couve, 1,6M de HCl por 5 horas para rúcula, 1,2M de HCl por 2 horas para alface, 1,7M de HCl por 4,3 horas para salsa e 0,8M de HCl por 2,5 horas para cebola. As condições cromatográficas utilizadas foram coluna Nova-Pak C18 (4ìm, 3,9x150mm), e fase móvel constituída de metanol e água, acidificados com 0,3% de ácido fórmico, em gradiente linear. Utilizando a metodologia analítica validada no Capítulo 2, no Capítulo 3 foram identificados e quantificados os flavonóides de alface lisa (6,73-9,77'g/g de quercetina), alface crespa (7,18-30,8'g/g de quercetina), cebola branca (323-362'g/g de quercetina), cebola roxa (390-423'g/g de quercetina), couve (256-399'g/g de quercetina e 333-339'g/g de kaempferol), espinafre (52,8-62,3'g/g de quercetina e 145-170'g/g de kaempferol), rúcula (137-143'g/g de quercetina e 402-501'g/g de kaempferol) e salsa (1521-1636'g/g de apigenina). Também foi avaliado o efeito sazonal nos teores destes compostos, sendo que estes tenderam a ser maiores no verão que no inverno, embora as diferenças não tenham sido estatisticamente significativas. No Capítulo 4, foram determinados os teores de flavonóides em sucos prontos para o consumo, sucos concentrados e polpas de caju, acerola e pitanga, e em amostras de cebola e salsa desidratadas. Os resultados indicaram perdas de flavonóides durante o processamento destes alimentos. Os teores nas amostras processadas foram nitidamente menores aos obtidos previamente nas amostras in natura. Os derivados de frutas apresentaram teores decrescentes na seguinte ordem: polpas, suco concentrado, suco pronto para consumo. Os teores de quercetina nas amostras de cebola desidratada foram bastante variados, indicando diferenças de variedades utilizadas como matéria-prima ou nas condições de processamento empregadas. Os resultados sugerem que estudos de monitoramento das perdas de flavonóides, da matéria-prima ao produto final, são altamente requeridos. O comportamento de flavonóis em couve, espinafre e rúcula minimamente processados, estocados em atmosfera modificada, em diferentes temperaturas, na presença e ausência de luz, foi avaliado e discutido no Capítulo 5. A qualidade sensorial dessas amostras também foi avaliada, para verificar a vida-de-prateleira. No geral, a vida útil foi negativamente influenciada pelo aumento na temperatura de estocagem na presença de luz. Não ocorreram perdas pronunciadas nos teores destes compostos durante a estocagem das três folhas minimamente processadas, podendo inclusive aumentar em certos períodos do armazenamento
Abstract: Had the increasing importance attributed to the flavonóides in the last years, decurrent of its action related to the prevention of degenerative illnesses, and allied to the lack of data of these composites in Brazilian foods, this study it had as objective to determine texts of flavonóis and flavonas in foods consumed in Brazil and to evaluate some factors that influence its levels in these foods. A bibliographical revision is presented in Chapter 1, in which the main beneficial effect to the health, analytical aspects and factors are described that influence texts of flavonóides in foods. These composites with beneficial action to the health, act as antirust, inhibiting of the proliferation cellular, antiestrogênicos and mediating intracellular, exerting protection mainly against cardiovascular cancer and illnesses. The determination of these composites normally is made using liquid chromatography of high efficiency with detector of arrangement of diodes. The levels of flavonóides in foods can be influenced by some factors, as station of the year, preparation and processing of foods. Chapter 2 describes the development and validation of the analytical methodology for determination of flavonóis and flavonas in hortaliças. Using Rotational Central Composed Delineation, the best conditions for extration and hydrolysis of the flavonóides found in the nature in the glicosídica form, its respective agliconas had been gotten. These conditions had been: 1,0M of HCl for 6 hours for spinach and borecole, 1,6M of HCl for 5 hours for rúcula, 1,2M of HCl for 2 hours for lettuce, 1,7M of HCl for 4,3 hours for parsley and 0,8M of HCl for 2,5 hours for onion. The used chromatographic conditions had been column Nova-Pak C18 (4ìm, 3,9x150mm), and mobile phase consisting of methanol and water, acidified with 0,3% of acid fórmico, in linear gradient. Using the validated analytical methodology in Chapter 2, in Chapter 3 they had been identified and quantified the flavonóides of smooth lettuce (6,73-9,77'g/g of quercetina), lettuce crespa (7,18-30,8'g/g of quercetina), white onion (323-362'g/g of quercetina), purple onion (390-423'g/g of quercetina), borecole (256-399'g/g of quercetina and 333-339'g/g of kaempferol), spinach (52,8-62,3'g/g of quercetina and 145-170'g/g of kaempferol), rúcula (137-143'g/g of quercetina and 402-501'g/g of kaempferol) and parsley (1521-1636'g/g of apigenina). Also the sazonal effect in texts of these composites was evaluated, being that these had tended to be bigger in the summer that in the winter, the differences have even so not been estatisticamente significant. In Chapter 4, the texts of flavonóides in ready juices for the consumption, intent juices and cashew pulps, acerola and pitanga had been determined, and in samples of dehydrated onion and parsley. The results had indicated losses of flavonóides during the processing of these foods. The texts in the processed samples had been nitidamente lesser to gotten previously in the samples in natura. The derivatives of fruits had presented decreasing texts in the following order: pulps, concentrated juice, ready juice for consumption. The texts of quercetina in the samples of dehydrated onion sufficiently had been varied, indicating differences of used varieties as raw material or in the employed conditions of processing. The results suggest that studies of monitoramento of the losses of flavonóides, of the raw material to the end item, highly are required. The behavior of flavonóis in borecole, spinach and rúcula minimamente processings, storaged in modified atmosphere, in different temperatures, na.presença and absence of light, was evaluated and argued in Chapter 5. The sensorial quality of these samples also was evaluated, to verify the life-of-shelf. In the generality, the useful life negative was influenced by the increase in the temperature of stockage na.presença of light. Sharp losses in texts of these composites had not occurred during the stockage of three minimamente processed leves, also being able to increase in certain periods of the storage
Doutorado
Doutor em Ciência de Alimentos
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Bombonati, Aline Yashima. "Flavonois em frutas e hortaliças : efeito do co cozimento e microfiltração." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/322501.
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Orientador: Delia B. Rodriguez-AmayaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Mestrado
Mestre em Ciência de Alimentos
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Eder, Christian. "Klonierung und Charakterisierung der Flavonoid 3'-Hydroxylase und der Flavonoid 3',5'-Hydroxylase." [S.l.] : [s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=963026275.
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Stewart, Amanda J. "Flavonoid occurrence, regulation in plant tissues and dietary contribution to health." Thesis, University of Glasgow, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366202.
Full textBooks on the topic "Flavonoli"
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Davies, Neal M., and Jaime A. Yáñez, eds. FLAVONOID PHARMACOKINETICS. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2012. http://dx.doi.org/10.1002/9781118468524.
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Caldwell, Charles R. Effect of divalent cations on the phenolic acids and flavonol glycosides of lettuce (Lactuca Sativa L.) leaf tissues. Beltsville, Md: USDA ARS BA, 2001.
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Davies, Neal M. Flavonoid Pharmacokinetics. Wiley & Sons, Incorporated, John, 2012.
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Kumar, Shashank. Flavonols As Cancer Preventive Agents: Recent Updates. Nova Science Publishers, Incorporated, 2021.
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(Editor), Jeffrey B. Harborne, and Herbert Baxter (Editor), eds. The Handbook to Flavonoid Pigments. Wiley, 1999.
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Kamboh, Asghar. Flavonoid-rich Foods -Super Foods of the Millennium: Health effects of flavonoid-rich foods. LAP Lambert Academic Publishing, 2012.
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Galati, Giuseppe. Dietary flavonoid/polyphenolic reactive metabolites and their biological properties. 2004.
Find full textBook chapters on the topic "Flavonoli"
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Yáñez, Jaime A., Connie M. Remsberg, Jody K. Takemoto, Karina R. Vega-Villa, Preston K. Andrews, Casey L. Sayre, Stephanie E. Martinez, and Neal M. Davies. "Polyphenols and Flavonoids: An Overview." In FLAVONOID PHARMACOKINETICS, 1–69. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2012. http://dx.doi.org/10.1002/9781118468524.ch1.
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Takemoto, Jody K., Stephanie E. Martinez, and Neal M. Davies. "Analysis of Flavonoids through Chromatography." In FLAVONOID PHARMACOKINETICS, 71–115. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2012. http://dx.doi.org/10.1002/9781118468524.ch2.
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Yáñez, Jaime A., Casey L. Sayre, Stephanie E. Martinez, and Neal M. Davies. "Chiral Methods of Flavonoid Analysis." In FLAVONOID PHARMACOKINETICS, 117–59. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2012. http://dx.doi.org/10.1002/9781118468524.ch3.
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Yáñez, Jaime A., Casey L. Sayre, and Neal M. Davies. "Preclinical Pharmacokinetics of Flavonoids." In FLAVONOID PHARMACOKINETICS, 161–93. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2012. http://dx.doi.org/10.1002/9781118468524.ch4.
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Sayre, Casey L., Karen D. Gerde, Jaime A. Yáñez, and Neal M. Davies. "Clinical Pharmacokinetics of Flavonoids." In FLAVONOID PHARMACOKINETICS, 195–247. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2012. http://dx.doi.org/10.1002/9781118468524.ch5.
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Martinez, Stephanie E., Neal M. Davies, and Jonathan K. Reynolds. "Toxicology and Safety of Flavonoids." In FLAVONOID PHARMACOKINETICS, 249–80. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2012. http://dx.doi.org/10.1002/9781118468524.ch6.
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Yáñez, Jaime A., Nagendra V. Chemuturi, Scott W. Womble, Casey L. Sayre, and Neal M. Davies. "Flavonoids and Drug Interactions." In FLAVONOID PHARMACOKINETICS, 281–319. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2012. http://dx.doi.org/10.1002/9781118468524.ch7.
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Wollenweber, E. "Flavones and flavonols." In The Flavonoids, 259–335. Boston, MA: Springer US, 1993. http://dx.doi.org/10.1007/978-1-4899-2911-2_7.
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Wollenweber, E., and M. Jay. "Flavones and flavonols." In The Flavonoids, 233–302. Boston, MA: Springer US, 1988. http://dx.doi.org/10.1007/978-1-4899-2913-6_7.
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Schomburg, Dietmar, and Dörte Stephan. "Flavonol 3-sulfotransferase." In Enzyme Handbook, 1025–28. Berlin, Heidelberg: Springer Berlin Heidelberg, 1997. http://dx.doi.org/10.1007/978-3-642-59025-2_192.
Full textConference papers on the topic "Flavonoli"
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Kim, Hanjong, Changwan Han, Otgonbayar Maidar, Sang-Soo Lee, and Seonghun Park. "Biomechanical Effects of Kaempferol Treatments on the Bone Healing Process of Murine Tibia." In ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-37810.
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Kaempferol is a typical flavonol-type flavonoid and has a protective effect on postmenopausal bone loss, and previous studies have reported that kaempferol treated groups show an increase in the callus size and bone mineral density as well as improvement in biomechanical behaviors in comparison with untreated control groups in the bone healing process. The present study aims at investigating the effect of kaempferol treatments on fractured murine tibia, by measuring kaempferol dose-dependent mechanical properties in the bone healing process of murine tibia fracture models. A stabilized fracture was generated at tibia by minor modification of the Hiltunen method for 8 weeks old ICR mice weighting 29.0 ∼ 30.5 g. Experimental mice were divided into 4 groups. Kaempferol of 0.2, 1.0, 5.0 mg/kg (body weight) with 20 % ethanol was administered to 3 groups and the remaining one group was only treated with 20 % ethanol as a control group. Three-point bending fracture tests were conducted to measure the mechanical properties (fracture load, fracture energy, stiffness) of murine tibiae at non-fractured regions near fracture sites 21 days after kaempferol treatments, via a custom-made biomechanical testing system (BTS, KST Co., Korea). The 5.0 mg/kg kaempferol treated group shows higher fracture load (20.54 ±5.04 N) than the control group (17.82 ±5.94 N). Fracture energy, total energy applied to tibia up to bone fracture, exhibited no significant differences between the control group and any of the kampferol treated groups, although both the 1.0 mg/kg kaempferol treated and control groups showed a little higher fracture energy than the 0.2 and 5.0 mg/kg kaempferol treated groups. Bone stiffness also did not show statistically significant differences between the control group and any of the kaempferol treated groups, with the highest stiffness value observed in the 1.0 mg/kg kaempferol treated group.
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Kim, Moon S., Edward H. Lee, Charles L. Mulchi, James E. McMurtrey III, Emmett W. Chappelle, and Randy A. Rowland. "Fluorescence imaging of soybean flavonol isolines." In Aerospace/Defense Sensing and Controls, edited by Ram M. Narayanan and James E. Kalshoven, Jr. SPIE, 1998. http://dx.doi.org/10.1117/12.312625.
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Rodríguez-Ramírez, Juan, Irene Chaparro-Hernández, Lilia L. Méndez-Lagunas, and Luis Gerardo Barriada-Bernal. "Effect of spray drying conditions on antioxidants activity, flavonoids and total phenolic compounds of stevia rebaudiana." In 21st International Drying Symposium. Valencia: Universitat Politècnica València, 2018. http://dx.doi.org/10.4995/ids2018.2018.7518.
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In this work the spray drying of the fresh stevia leaves aqueous extract without encapsulating agents was carried out. The effect of the inlet air temperature (160-200 ºC) and the feed flow rate (2-3 kg/h) on the total phenolic content, the total flavonoid content and the antioxidant capacity were evaluated using Folin-Ciocalteau, aluminum chloride and DPPH methods respectively. The inlet air temperature had a significant effect on all parameters evaluated that showed a decrease when increasing the inlet air temperature, the feed flow rate had a significant effect on total flavonoids content and the antioxidant capacity, by increasing the feed flow rate the inhibition of the DPPH radical decreased and the total flavonoid content increased. The treatment at 160 ºC and 3 kg/h retained highest total flavonoid content and the antioxidant capacity. Keywords: Phenolic compounds, stevia, spray drying, antioxidant capacity
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Huang, Xiaoli, T. Li, S. N. Li, Z. H. Wu, and J. Xue. "Hot air drying combined vacuum-filling nitrogen drying of apple slices: Drying characteristics and nutrients." In 21st International Drying Symposium. Valencia: Universitat Politècnica València, 2018. http://dx.doi.org/10.4995/ids2018.2018.7477.
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In this paper, hot air drying (HAD) was applied when moisture content of apple slices range from 50% to 86%, and then vacuum-filling nitrogen drying (VFND) was used till moisture content reaching 7%. Results showed that, the drying rate of apple slice during VFND period increased with temperature increment and decreased with increment of slice thickness; compared to freezing dried samples, samples dried in this research were owned lower Vc and higher flavonoid; when HAD (70℃,3.0m/s)+VFND(relative pressure 0.08MPa, 50℃) and thickness of 6.0mm, nutrients reached better levels: retentions of Vc, total phenolics and flavonoid were 1.63mg/100g, 4.07mg/100g and 2.10mg/100g, respectively. Keywords: apple slices, hot air drying, vacuum-filling nitrogen drying, drying rate, nutrients
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Usmanov, I. Yu, A. V. Scherbakov, V. B. Ivanov, and E. R. Yumagulova. "Fractal analysis of flavonoid biosynthesis system." In IX Congress of society physiologists of plants of Russia "Plant physiology is the basis for creating plants of the future". Kazan University Press, 2019. http://dx.doi.org/10.26907/978-5-00130-204-9-2019-446.
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Cidade, Honorina, Joana Moreira, Sofia Salazar, Mariana Leão, Madalena Pinto, and Lucília Saraiva. "Promising caspase modulators with flavonoid scaffold." In 1st International Electronic Conference on Medicinal Chemistry. Basel, Switzerland: MDPI, 2015. http://dx.doi.org/10.3390/ecmc-1-a013.
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Kruchenok, Julia V., Nicolai A. Nemkovich, A. N. Sobchuk, E. P. Petrov, Anatoly N. Rubinov, V. G. Pivovarenko, and Wolfram Baumann. "Red-edge excitation effect in intramolecular proton transfer in flavonols." In XVII International Conference on Coherent and Nonlinear Optics (ICONO 2001), edited by Andrey Y. Chikishev, Valentin A. Orlovich, Anatoly N. Rubinov, and Alexei M. Zheltikov. SPIE, 2002. http://dx.doi.org/10.1117/12.468924.
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Nechaeva, M. V., and I. F. Golovatskaya. "The effect of sodium selenite on the secondary metabolism of cell culture Lychnis chalcedonica in vitro." In 2nd International Scientific Conference "Plants and Microbes: the Future of Biotechnology". PLAMIC2020 Organizing committee, 2020. http://dx.doi.org/10.28983/plamic2020.181.
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We studied the effect of sodium selenite (Se) on the secondary metabolism of Lychnis chalcedonica L. cell culture in vitro. It was found that low concentrations of Se reduce the flavonoid content, but do not change the content of saponins.
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Kravchenko, I. V., G. M. Kukurichkin, and N. V. Nakonechniy. "QUANTITATIVE CONTENT OF PHOTOSYNTHETIC PIGMENTS IN SOME PLANTS OF NATURAL PARK «SIBERIAN UVALY»." In Prirodopol'zovanie i ohrana prirody: Ohrana pamjatnikov prirody, biologicheskogo i landshaftnogo raznoobrazija Tomskogo Priob'ja i drugih regionov Rossii. Izdatel'stvo Tomskogo gosudarstvennogo universiteta, 2020. http://dx.doi.org/10.17223/978-5-94621-954-9-2020-44.
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Regularities of photosynthetic pigments accumulation (chlorophylls, carotenoids, and flavonoid compounds) in plants growing on the territory of the «Deep Sabun» base of the «Siberian Uvaly» Natural Park have been analyzed to evaluate the ecological and biochemical status of the most significant plant species.
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Richardson, P. Mick. "Flavonoid Chemistry and the Taxonomy of Cycads." In Symposium CYCAD 87. The New York Botanical Garden Press, 1990. http://dx.doi.org/10.21135/893273507.012.
Full textReports on the topic "Flavonoli"
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Ivanova, Victoria, Milka Todorova, Paraskev Nedialkov, and Antoaneta Trendafilova. A New Flavonol Acylglucoside from Inula aschersoniana Janka Var. aschersoniana. "Prof. Marin Drinov" Publishing House of Bulgarian Academy of Sciences, April 2021. http://dx.doi.org/10.7546/crabs.2021.04.05.
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Kozhuharova, Asya, Marina Stanilova, Milena Nikolva, Rumen Denev, and Strahil Berkov. Glycyrrhizin and Flavonoid Contents of the Bulgarian Glycyrrhiza glabra Populations. "Prof. Marin Drinov" Publishing House of Bulgarian Academy of Sciences, July 2021. http://dx.doi.org/10.7546/crabs.2021.07.05.
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Harding, Scott, A, Chung-jui Tsai, and Lindroth, Richard, L. A genomics investigation of partitioning into and among flavonoid-derived condensed tannins for carbon sequestration in Populus. Office of Scientific and Technical Information (OSTI), March 2013. http://dx.doi.org/10.2172/1069258.
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Li, Lu, Kexin Ji, Nini Jin, Yueyue He, Christine Boesch, and Xinqi Liu. Does flavonoid supplementation alleviate non-alcoholic fatty liver disease? A systematic review and meta-analysis of randomized controlled trials. INPLASY - International Platform of Registered Systematic Review and Meta-analysis Protocols, June 2022. http://dx.doi.org/10.37766/inplasy2022.6.0057.
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Phillips, Donald, and Yoram Kapulnik. Using Flavonoids to Control in vitro Development of Vesicular Arbuscular Mycorrhizal Fungi. United States Department of Agriculture, January 1995. http://dx.doi.org/10.32747/1995.7613012.bard.
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Vesicular-arbuscular mycorrhizal (VAM) fungi and other beneficial rhizosphere microorganisms, such as Rhizobium bacteria, must locate and infect a host plant before either symbiont profits. Although benefits of the VAM association for increased phosphorous uptake have been widely documented, attempts to improve the fungus and to produce agronomically useful amounts of inoculum have failed due to a lack of in vitro production methods. This project was designed to extend our prior observation that the alfalfa flavonoid quercetin promoted spore germination and hyphal growth of VAM fungi in the absence of a host plant. On the Israeli side of the project, a detailed examination of changes in flavonoids and flavonoid-biosynthetic enzymes during the early stages of VAM development in alfalfa found that VAM fungi elicited and then suppressed transcription of a plant gene coding for chalcone isomerase, which normally is associated with pathogenic infections. US workers collaborated in the identification of flavonoid compounds that appeared during VAM development. On the US side, an in vitro system for testing the effects of plant compounds on fungal spore germination and hyphal growth was developed for use, and intensive analyses of natural products released from alfalfa seedlings grown in the presence and absence of microorganisms were conducted. Two betaines, trigonelline and stachydrine, were identified as being released from alfalfa seeds in much higher concentrations than flavonoids, and these compounds functioned as transcriptional signals to another alfalfa microsymbiont, Rhizobium meliloti. However, these betaines had no effect on VAM spore germination or hyphal growth i vitro. Experiments showed that symbiotic bacteria elicited exudation of the isoflavonoids medicarpin and coumestrol from legume roots, but neither compound promoted growth or germination of VAM fungi in vitro. Attempts to look directly in alfalfa rhizosphere soil for microbiologically active plant products measured a gradient of nod-gene-inducing activity in R. meliloti, but no novel compounds were identified for testing in the VAM fungal system in vitro. Israeli field experiments on agricultural applications of VAM were very successful and developed methods for using VAM to overcome stunting in peanuts and garlic grown in Israel. In addition, deleterious effects of soil solarization on growth of onion, carrot and wheat were linked to effects on VAM fungi. A collaborative combination of basic and applied approaches toward enhancing the agronomic benefits of VAM asociations produced new knowledge on symbiotic biology and successful methods for using VAM inocula under field conditions
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Prusky, Dov, Noel Keen, and Rolf Christoffersen. Involvement of Epicatechin in the Regulation of Natural Resistance of Avocado Fruit against Postharvest Pathogens. United States Department of Agriculture, January 1997. http://dx.doi.org/10.32747/1997.7613028.bard.
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In this project it was found that the activation of the mechanism of resistance in avocado fruits to Colletotrichum gloeosporioides depends on the increase of the level of the preformed antifungal diene. This increase is regulated by the synthesis of the flavonoid epicatechin present in the fruit peel. Epicatechin is an inhibitor of the enzyme lipoxygenase whose activity catalyze the breakdown of the antifungal diene. Increase in epicatechin concentration inhibits the breakdown of the antifungal compound and since the compound is continuously synthesized, both combined processes result in the increase of the antifungal level. Biotic and abiotic elicitors affecting the mechanism of resistance, all activate the synthesis of epicatechin. As abiotic elicitors were tested wounding, ethylene and CO2 treatments. As biotic elicitors were tested challenge inoculation with C. gloeosporioides, Colletotrichum magna (a non pathogen of avocado) and also non pathogenic strain of C. magna. In all the cases activation of the key enzymes of the phenylpropanoic pathway is followed by an enhance in the level of epicatechin and the antifungal diene. In order to determine the level of regulation by the different elicitors of the mechanism, the genes encoding for key enzymes of the phenylpropanoic pathway were cloned and it was found that the different elicitors regulate the expression of those genes at a translational level. Modulation of the mechanism of resistance could also be done by activation of lipoxygenase gene expression. For this purpose lipoxygenase from avocado was cloned and its over-expression, under the effect of methyl jasmonate, determined.
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Miller, Gad, and Jeffrey F. Harper. Pollen fertility and the role of ROS and Ca signaling in heat stress tolerance. United States Department of Agriculture, January 2013. http://dx.doi.org/10.32747/2013.7598150.bard.
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The long-term goal of this research is to understand how pollen cope with stress, and identify genes that can be manipulated in crop plants to improve reproductive success during heat stress. The specific aims were to: 1) Compare heat stress dependent changes in gene expression between wild type pollen, and mutants in which pollen are heat sensitive (cngc16) or heat tolerant (apx2-1). 2) Compare cngc16 and apx2 mutants for differences in heat-stress triggered changes in ROS, cNMP, and Ca²⁺ transients. 3) Expand a mutant screen for pollen with increased or decreased thermo-tolerance. These aims were designed to provide novel and fundamental advances to our understanding of stress tolerance in pollen reproductive development, and enable research aimed at improving crop plants to be more productive under conditions of heat stress. Background: Each year crop yields are severely impacted by a variety of stress conditions, including heat, cold, drought, hypoxia, and salt. Reproductive development in flowering plants is highly sensitive to hot or cold temperatures, with even a single hot day or cold night sometimes being fatal to reproductive success. In many plants, pollen tube development and fertilization is often the weakest link. Current speculation about global climate change is that most agricultural regions will experience more extreme environmental fluctuations. With the human food supply largely dependent on seeds, it is critical that we consider ways to improve stress tolerance during fertilization. The heat stress response (HSR) has been intensively studied in vegetative tissues, but is poorly understood during reproductive development. A general paradigm is that HS is accompanied by increased production of reactive oxygen species (ROS) and induction of ROS-scavenging enzymes to protect cells from excess oxidative damage. The activation of the HSR has been linked to cytosolic Ca²⁺ signals, and transcriptional and translational responses, including the increased expression of heat shock proteins (HSPs) and antioxidative pathways. The focus of the proposed research was on two mutations, which have been discovered in a collaboration between the Harper and Miller labs, that either increase or decrease reproductive stress tolerance in a model plant, Arabidopsis thaliana (i.e., cngc16--cyclic nucleotide gated channel 16, apx2-1--ascorbate peroxidase 2,). Major conclusions, solutions, achievements. Using RNA-seq technology, the expression profiles of cngc16 and apx2 pollen grains were independently compared to wild type under favourable conditions and following HS. In comparison to a wild type HSR, there were 2,776 differences in the transcriptome response in cngc16 pollen, consistent with a model in which this heat-sensitive mutant fails to enact or maintain a normal wild-type HSR. In a comparison with apx2 pollen, there were 900 differences in the HSR. Some portion of these 900 differences might contribute to an improved HSR in apx2 pollen. Twenty-seven and 42 transcription factor changes, in cngc16 and apx2-1, respectively, were identified that could provide unique contributions to a pollen HSR. While we found that the functional HS-dependent reprogramming of the pollen transcriptome requires specific activity of CNGC16, we identified in apx2 specific activation of flavonol-biosynthesis pathway and auxin signalling that support a role in pollen thermotolerance. Results from this study have identified metabolic pathways and candidate genes of potential use in improving HS tolerance in pollen. Additionally, we developed new FACS-based methodology that can quantify the stress response for individual pollen in a high-throughput fashion. This technology is being adapted for biological screening of crop plant’s pollen to identify novel thermotolerance traits. Implications, both scientific and agricultural. This study has provided a reference data on the pollen HSR from a model plant, and supports a model that the HSR in pollen has many differences compared to vegetative cells. This provides an important foundation for understanding and improving the pollen HSR, and therefor contributes to the long-term goal of improving productivity in crop plants subjected to temperature stress conditions. A specific hypothesis that has emerged from this study is that pollen thermotolerance can be improved by increasing flavonol accumulation before or during a stress response. Efforts to test this hypothesis have been initiated, and if successful have the potential for application with major seed crops such as maize and rice.
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Elmann, Anat, Orly Lazarov, Joel Kashman, and Rivka Ofir. therapeutic potential of a desert plant and its active compounds for Alzheimer's Disease. United States Department of Agriculture, March 2015. http://dx.doi.org/10.32747/2015.7597913.bard.
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We chose to focus our investigations on the effect of the active forms, TTF and AcA, rather than the whole (crude) extract. 1. To establish cultivation program designed to develop lead cultivar/s (which will be selected from the different Af accessions) with the highest yield of the active compounds TTF and/or achillolide A (AcA). These cultivar/s will be the source for the purification of large amounts of the active compounds when needed in the future for functional foods/drug development. This task was completed. 2. To determine the effect of the Af extract, TTF and AcA on neuronal vulnerability to oxidative stress in cultured neurons expressing FAD-linked mutants.Compounds were tested in N2a neuroblastoma cell line. In addition, we have tested the effects of TTF and AcA on signaling events promoted by H₂O₂ in astrocytes and by β-amyloid in neuronal N2a cells. 3. To determine the effect of the Af extract, TTF and AcA on neuropathology (amyloidosis and tau phosphorylation) in cultured neurons expressing FAD-linked mutants. 4. To determine the effect of A¦ extract, AcA and TTF on FAD-linked neuropathology (amyloidosis, tau phosphorylation and inflammation) in transgenic mice. 5. To examine whether A¦ extract, TTF and AcA can reverse behavioral deficits in APPswe/PS1DE9 mice, and affect learning and memory and cognitive performance in these FAD-linked transgenic mice. Background to the topic.Neuroinflammation, oxidative stress, glutamate toxicity and amyloid beta (Ab) toxicity are involved in the pathogenesis of Alzheimer's diseases. We have previously purified from Achilleafragrantissimatwo active compounds: a protective flavonoid named 3,5,4’-trihydroxy-6,7,3’-trimethoxyflavone (TTF, Fl-72/2) and an anti-inflammatory sesquiterpenelactone named achillolide A (AcA). Major conclusions, solutions, achievements. In this study we could show that TTF and AcA protected cultured astrocytes from H₂O₂ –induced cell death via interference with cell signaling events. TTF inhibited SAPK/JNK, ERK1/2, MEK1 and CREBphosphorylation, while AcA inhibited only ERK1/2 and MEK1 phosphorylation. In addition to its protective activities, TTF had also anti-inflammatory activities, and inhibited the LPS-elicited secretion of the proinflammatorycytokinesInterleukin 6 (IL-6) and IL-1b from cultured microglial cells. Moreover, TTF and AcA protected neuronal cells from glutamate and Abcytotoxicity by reducing the glutamate and amyloid beta induced levels of intracellular reactive oxygen species (ROS) and via interference with cell signaling events induced by Ab. These compounds also reduced amyloid precursor protein net processing in vitro and in vivo in a mouse model for Alzheimer’s disease and improvedperformance in the novel object recognition learning and memory task. Conclusion: TTF and AcA are potential candidates to be developed as drugs or food additives to prevent, postpone or ameliorate Alzheimer’s disease. Implications, both scientific and agricultural.The synthesis ofAcA and TTF is very complicated. Thus, the plant itself will be the source for the isolation of these compounds or their precursors for synthesis. Therefore, Achilleafragrantissima could be developed into a new crop with industrial potential for the Arava-Negev area in Israel, and will generate more working places in this region.
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Kanner, Joseph, Edwin Frankel, Stella Harel, and Bruce German. Grapes, Wines and By-products as Potential Sources of Antioxidants. United States Department of Agriculture, January 1995. http://dx.doi.org/10.32747/1995.7568767.bard.
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Several grape varieties and red wines were found to contain large concentration of phenolic compounds which work as antioxidant in-vitro and in-vivo. Wastes from wine production contain antioxidants in large amounts, between 2-6% on dry material basis. Red wines but also white wines were found to prevent lipid peroxidation of turkey muscle tissues stored at 5oC. The antioxidant reaction of flavonoids found in red wines against lipid peroxidation were found to depend on the structure of the molecule. Red wine flavonoids containing an orthodihydroxy structure around the B ring were found highly active against LDL and membrane lipid peroxidation. The antioxidant activity of red wine polyphenols were also found to be dependent on the catalyzer used. In the presence of H2O2-activated myoglobin, the inhibition efficiency was malvidin 3-glucoside>catechin>malvidin>resveratol. However, in the presence of an iron redox cycle catalyzer, the order of effectiveness was resveratol>malvidin 3-glucoside = malvidin>catechin. Differences in protein binding were found to affect antioxidant activity in inhibiting LDL oxidation. A model protein such as BSA, was investigated on the antioxidant activity of phenolic compounds, grape extracts, and red wines in a lecithin-liposome model system. Ferulic acid followed by malvidin and rutin were the most efficient in inhibiting both lipid and protein oxidation. Catechin, a flavonal found in red-wines in relatively high concentration was found to inhibit myoglobin catalyzed linoleate membrane lipid peroxidation at a relatively very low concentration. This effect was studied by the determination of the by-products generated from linoleate during oxidation. The study showed that hydroperoxides are catalytically broken down, not to an alcohol but most probably to a non-radical adduct. The ability of wine-phenolics to reduce iron and from complexes with metals were also demonstrated. Low concentration of wine phenolics were found to inhibit lipoxygenase type II activity. An attempt to understand the bioavailability in humans of antocyanins from red wine showed that two antocyanins from red wine were found unchanged in human urine. Other antocyanins seems to undergo molecular modification. In hypercholesterolemic hamsters, aortic lipid deposition was significantly less in animals fed diets supplemented with either catechin or vitamin E. The rate of LDL accumulation in the carotid arteries was also significantly lower in the catechin and vitamin E animal groups. These results suggested a novel mechanism by which wine phenolics are associated with decreased risk of coronary heart diseases. This study proves in part our hypothesis that the "French Paradox" could be explained by the action of the antioxidant effects of phenolic compounds found at high concentration in red wines. The results of this study argue that it is in the interest of public health to increase the consumption of dietary plant falvonoids. Our results and these from others, show that the consumption of red wine or plant derived polyphenolics can change the antioxidant tone of animal and human plasma and its isolated components towards oxidative reactions. However, we need more research to better understand bioavailability and the mechanism of how polyphenolics affect health and disease.
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Eyal, Yoram, Gloria Moore, and Efraim Lewinsohn. Study and Manipulation of the Flavanoid Biosynthetic Pathway in Citrus for Flavor Engineering and Seedless Fruit. United States Department of Agriculture, October 2003. http://dx.doi.org/10.32747/2003.7570547.bard.
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The proposal was aimed to identify and functionally characterize key genes/enzymes in the citrus flavanone neohesperidoside biosynthetic pathway and to use them as tools for metabolic engineering to decrease bitterness levels in grapefruit. The proposed section on fruit seediness was dropped as suggested by the reviewers of the proposal. Citrus flavor and aroma is composed of complex combinations of soluble and volatile compounds. The former includes mainly sugars, acids and flavanones, a subgroup of flavonoids that includes bitter compounds responsible for the bitter flavor of grapefruit and pummelo. Bitter species contain mostly bitter flavanone neohesperidosides, while non-bitter species contain mostly tasteless flavanone rutinosides. Both flavanone versions are diglycosides consisting of a rhamnose-glucose oligosaccharide a-linked at position 7 to the flavanone skeleton. However, in the bitter neohesperidosides the rhamnose is attached at position 2 of the glucose moiety, while in the tasteless rutinosides the rhamnose is attached at position 6 of the glucose moiety. Thus, the position of the rhamnose moiety, determined by the specificity of the last enzymes in the pathway- rhamnosyltransferase (1,2 or 1,6 specificity), is the determinant of the bitter flavor. Flavanones, like all flavonoids are synthesized via one of the branches of the phenylpropanoid pathway; the first committed step is catalyzed by the enzyme Chalcone synthase (CHS) followed by Chalcone isomerase (CHI). During the course of the work a key gene/enzyme in the biosynthesis of the bitter flavanones, a 1,2 rhamnosyltransferase (1,2RT), was functionally characterized using a transgenic cell-culture biotransformation system, confirming that this gene is a prime candidate for metabolic engineering of the pathway. This is the first direct functional evidence for the activity of a plant recombinant rhamnosyltransferase, the first confirmed rhamnosyltransferase gene with 1,2 specificity and the second confirmed rhamnosyltransferase gene altogether in plants. Additional genes of the flavanone pathway that were isolated during this work and are potential tools for metabolic engineering include (I) A putative 1,6 rhamnosyltransferase (1,6RT) from oranges, that is presumed to catalyze the biosynthesis of the tasteless flavanones. This gene is a prime candidate for use in future metabolic engineering for decreased bitterness and is currently being functionally characterized using the biotransformation system developed for characterizing rhamnosyltransferases. (2) A putative 7-0-glucosyltransferase presumed to catalyze the first glycosylation step of the flavanone aglycones. Silencing of gene expression in grapefruit was attempted using three genes: (1) The "upstream" flavonoid biosynthesis genes CHS and CHI, by antisense and co-suppression; and (2) The "downstream" 1,2R T, by an RNAi approach. CHS and CHI silencing resulted in some plants with a dramatically decreased level of the bitter flavanone neohesperidoside naringin in leaves. We have yet to study the long-term effect of silencing these genes on tree physiology, and on the actual bitterness of fruit. The effect of 1,2RT silencing on naringin content in grapefruit has yet to be examined, but a slow growth phenotype for these plants was noted. We speculate that silencing of the final glycosylation step of the flavanones delays their evacuation to the vacuole, resulting in accumulation of flavanones in the cytoplasm, causing inhibitory effects on plant growth. This speculation is yet to be established at the product level. Future metabolic engineering experiments are planned with 1,6RT following functional characterization.