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Strategies to improve the solubility and stability of stilbene antioxidants: a comparative study between cyclodextrins and bile acids

Silva, Filomena; Figueiras, Ana; Gallardo, Eugenia; Nerín, Cristina; Domingues, Fernanda C.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
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Aiming at the development of an active food packaging, the goal of this study was to increase stilbenes (resveratrol (RV), pterostilbene (PT) and pinosylvin (PS)) aqueous solubility and stability using hydropropyl-cyclodextrins (HP-CDs) and bile salts. To evaluate stilbene concentration, an HPLC-DAD method was validated. Stilbene solubility was improved by the formation of inclusion complexes and micellar systems with higher solubility values obtained for the inclusion complexes with cyclodextrins. Inclusion complexes revealed a 1:1 stoichiometry for RV and PT and a 1:2 for PS. Solid state characterisation was carried out using X-ray diffraction, Fourier transform infrared spectroscopy and differential scanning calorimetry. 1H NMR studies were also performed to characterise the prepared complexes. Photostability studies revealed that CDs were able to increase stilbene photostability at 4 °C. This work showed that stable stilbene solutions can be achieved using hydroxypropyl-CDs, contributing for their incorporation in several materials for the food and pharmaceutical industries.

Synthesis and Anti-Mycobacterium tuberculosis Evaluation of Aza-Stilbene Derivatives

Pavan, Fernando R.; de Carvalho, Gustavo Senra G.; da Silva, Adilson D.; Leite, Clarice Q. F.
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica Formato: 1113-1119
ENG
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Processo FAPESP: 08/10390-2; Processo FAPESP: 09/06499-1; Tuberculosis (TB) is a truly global disease, found in every country on earth. One-third of humanity, over 2 billion people, carry the bacillus that causes TB and 2 million people die of the disease each year. Despite that, no new specific drug against Mycobacterium tuberculosis has been developed since the 1960s. There are several candidates for new anti-TB agents, but none proven clinically effective. Stilbenes are compounds found in numerous medicinal plants and food products with some known biological and even antimycobacterial activity. This paper describes the synthesis and the anti-M. tuberculosis activity of eight stilbene analogues. The synthesis and characterization of these compounds are shown, and the results compared with one "first"-line drug used in current therapy.

Phenolic Composition of the Brazilian Seedless Table Grape Varieties BRS Clara and BRS Morena

Lago-Vanzela, Ellen Silva; Da-Silva, Roberto; Gomes, Eleni; Garcia-Romero, Esteban; Hermosin-Gutierrez, Isidro
Fonte: Amer Chemical Soc Publicador: Amer Chemical Soc
Tipo: Artigo de Revista Científica Formato: 8314-8323
ENG
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); The detailed phenolic composition (anthocyanins, flavonols, hydroxycinnamic acid derivatives, stilbenes, and flavan-3-ols) in the skin and flesh of the new BRS Clara and BRS Morena seedless table grapes has been studied using HPLC-DAD-ESI-MS/MS. The two grapes, especially BRS Morena, contained high amounts of phenolic compounds, mainly located in their skins and qualitatively not different from those found in Vitis vinifera grapes. In addition, BRS Morena (a teinturier variety) showed qualitatively different phenolic compositions in its skin and flesh, mainly affecting the anthocyanin and flavonol profiles. Consistent with high phenolic contents, high antioxidant capacity values were registered for both grape varieties, especially for BRS Morena. Proanthocyanidins and hydroxycinnamoyl-tartaric acids were the major phenolic compounds found in BRS Clara and were also important in BRS Morena, although anthocyanins were the main phenolic compounds in the latter case. These results suggest that the entire grapes, including the skin...

Estudo químico e atividades antiproliferativa, tripanocida e leishmanicida de Maxillaria picta

Almeida,Thiago L. de; Monteiro,Josiane A.; Lopes,Greice K. P.; Chiavelli,Lucas U. R.; Santin,Silvana M. de O.; Silva,Cleuza C. da; Kaplum,Vanessa; Scariot,Débora B.; Nakamura,Celso V.; Ruiz,Ana L. T. G.; Carvalho,João E.; Faria,Ricardo T. de; Pomini,Arm
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2014 PT
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The chemical study of the orchid Maxillaria picta resulted in the isolation of the bioactive stilbenes phoyunbene B and phoyunbene C, in addition to four phenolic acids, one xanthone, steroidal compounds and two triterpenes. Crude extract, fractions, subfractions and the isolated xanthone were evaluated for anticancer activity against human tumor cell lines and against evolutionary forms of T. cruzi and L. amazonensis. The structures of the compounds were determined by GC-MS, and ¹H NMR, 13C NMR spectral methods as well as bidimensional techniques.

Separation and purification of three stilbenes from the radix of Polygonum cillinerve (Nakai) Ohwl by macroporous resin column chromatography combined with high-speed counter-current chromatography

Chi,Xiaofeng; Xing,Yuxiu; Xiao,Yuancan; Dong,Qi; Hu,Fengzu
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2014 EN
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An effective method for the rapid separation and purification of three stilbenes from the radix of Polygonum cillinerve (Nakai) Ohwl by macroporous resin column chromatography combined with high-speed counter-current chromatography (HSCCC) was successfully established. In the present study, a two-phase solvent system composed of chloroform-n-butanol-methanol-water (4:1:4:2, v/v/v/v) was used for HSCCC separation. A one-step separation in 4 h from 150 mg of crude extract produced 26.3 mg of trans-resveratrol-3-O-glucoside, 42.0 mg of pieceid-2"-O-gallate, and 17.9 mg of trans-resveratrol with purities of 99.1%, 97.8%, and 99.4%, respectively, as determined by high-performance liquid chromatography (HPLC). The chemical structures of these compounds were identified by nuclear magnetic resonance (NMR) spectroscopy.

Stilbenes from Deguelia rufescens var. urucu (Ducke) A. M. G. Azevedo leaves: effects on seed germination and plant growth

Lobo,Lívia T.; Silva,Geilson A. da; Freitas,Manolo C. C. de; Souza Filho,Antonio Pedro S.; Silva,Milton N. da; Arruda,Alberto C.; Guilhon,Giselle M. S. P.; Santos,Lourivaldo S.; Santos,Alberdan S.; Arruda,Mara S. P.
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2010 EN
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The Amazon biodiversity may provide plants whose chemical substances are capable of controlling weeds. In this study we report the isolation and identification of five stilbenes from the leaves of "timbó vermelho" (Deguelia rufescens var. urucu): 4-methoxylonchocarpene (1); 3,5-dimethoxy-4´-hydroxy-3´-prenyl-trans-stilbene (2), lonchocarpene (3), 3,5-dimethoxy-4´-O-prenyl-trans-stilbene (4) and pterostilbene (5). Compounds 2 and 4 are new natural products although 2 has been previously cited as synthesis product. Potential allelopathic activity for 1, 2 and 4 was evaluated over seed germination and plant growth of Mimosa pudica weed. The observed effects on seed germination did not vary significantly (p > 0.05) when the analysis of phytotoxicity was performed with the substances alone, the maximum inhibition did not exceed 20%. The most intense inhibitions on radicle and hypocotyl development were found for compound 4 (p < 0.05). When tested in pairs, showed antagonism for seed germination and synergism for radicle and hypocotyl development.

Cytotoxic Prenylated Stilbenes and Flavonoids from Macaranga alnifolia from the Madagascar Rainforest#

Yoder, Brent J.; Cao, Shugeng; Norris, Andrew; Miller, James S.; Ratovoson, Fidy; Razafitsalama, Jeremi; Andriantsiferana, Rabodo; Rasamison, Vincent E.; Kingston, David G. I.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
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Bioassay-guided fractionation of an extract of the fruit of Macaranga alnifolia from Madagascar led to the isolation of four new prenylated stilbenes, schweinfurthins E–H (1–4), and one new geranylated dihydroflavonol, alnifoliol (5). The known prenylated stilbene, vedelianin (6), and the known geranylated flavonoids, bonanniol A (7), diplacol (8), bonannione A (9) and diplacone (10), were also isolated. All ten compounds were tested for antiproliferative activity in the A2780 human ovarian cancer cell line assay. Vedelianin (IC50 = 0.13 µM) exhibited the greatest activity among all isolates, while schweinfurthin E (IC50 = 0.26 µM) was the most potent of the new compounds.

Quantitation of Flavanols, Proanthocyanidins, Isoflavones, Flavanones, Dihydrochalcones, Stilbenes, Benzoic Acid Derivatives Using Ultraviolet Absorbance after Identification by Liquid Chromatography–Mass Spectrometry

Lin, Long-Ze; Harnly, James M.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
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A general method was developed for the systematic quantitation of flavanols, proanthocyanidins, isoflavones, flavanones, dihydrochalcones, stilbenes, and hydroxybenzoic acid derivatives (mainly hydrolyzable tannins) based on UV band II absorbance arising from the benzoyl structure. The compound structures and the wavelength maximum were well correlated and were divided into four groups: the flavanols and proanthocyanidins at 278 nm, hydrolyzable tannins at 274 nm, flavanones at 288 nm, and isoflavones at 260 nm. Within each group, molar relative response factors (MRRFs) were computed for each compound based on the absorbance ratio of the compound and the group reference standard. Response factors were computed for the compounds as purchased (MRRF), after drying (MRRFD), and as the best predicted value (MRRFP). Concentrations for each compound were computed based on calibration with the group reference standard and the MRRFP. The quantitation of catechins, proanthocyanidins, and gallic acid derivatives in white tea was used as an example.

Advanced Knowledge of Three Important Classes of Grape Phenolics: Anthocyanins, Stilbenes and Flavonols

Flamini, Riccardo; Mattivi, Fulvio; De Rosso, Mirko; Arapitsas, Panagiotis; Bavaresco, Luigi
Fonte: Molecular Diversity Preservation International (MDPI) Publicador: Molecular Diversity Preservation International (MDPI)
Tipo: Artigo de Revista Científica
Publicado em 27/09/2013 EN
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Grape is qualitatively and quantitatively very rich in polyphenols. In particular, anthocyanins, flavonols and stilbene derivatives play very important roles in plant metabolism, thanks to their peculiar characteristics. Anthocyanins are responsible for the color of red grapes and wines and confer organoleptic characteristics on the wine. They are used for chemotaxonomic studies and to evaluate the polyphenolic ripening stage of grape. They are natural colorants, have antioxidant, antimicrobial and anticarcinogenic activity, exert protective effects on the human cardiovascular system, and are used in the food and pharmaceutical industries. Stilbenes are vine phytoalexins present in grape berries and associated with the beneficial effects of drinking wine. The principal stilbene, resveratrol, is characterized by anticancer, antioxidant, anti-inflammatory and cardioprotective activity. Resveratrol dimers and oligomers also occur in grape, and are synthetized by the vine as active defenses against exogenous attack, or produced by extracellular enzymes released from pathogens in an attempt to eliminate undesirable toxic compounds. Flavonols are a ubiquitous class of flavonoids with photo-protection and copigmentation (together with anthocyanins) functions. The lack of expression of the enzyme flavonoid 3′...

Effect of natural flavonoids, stilbenes and caffeic acid oligomers on protein glycation

SASAKI, KENROH; CHIBA, SYUKO; YOSHIZAKI, FUMIHIKO
Fonte: D.A. Spandidos Publicador: D.A. Spandidos
Tipo: Artigo de Revista Científica
EN
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The aim of the present study was to identify the inhibitory activity of natural flavonoids, stilbenes and caffeic acid oligomers on protein glycation. Antioxidant activity was evaluated using 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activity. The production of 3-deoxyglucosone (3-DG) and advanced glycation end products (AGEs) by glycation reactions were determined by high-performance liquid chromatography and fluorescence, respectively. Certain flavonoids, stilbenes and caffeic acid oligomers prevented AGE production and the IC50 values of the compounds were compared. These examined compounds are assumed to suppress AGE generation by inhibiting the increase in 3-DG production through a specific unknown mechanism in the early phase of the Maillard reaction, by inhibiting the generation of active oxygen in the later phase and by suppressing the progression of the reaction. Regular, daily consumption of these compounds in the form of a food or extract is expected to aid in the prevention or inhibition of non-enzymatic amino acid glycation in the living body, which is possibly associated with aging, diabetic complications, arteriosclerotic diseases and Alzheimer’s disease, and they may also be effective agents in cosmetics promoting anti-aging.

Jasmonates elicit different sets of stilbenes in Vitis vinifera cv. Negramaro cell cultures

Taurino, Marco; Ingrosso, Ilaria; D’amico, Leone; De Domenico, Stefania; Nicoletti, Isabella; Corradini, Danilo; Santino, Angelo; Giovinazzo, Giovanna
Fonte: Springer International Publishing Publicador: Springer International Publishing
Tipo: Artigo de Revista Científica
Publicado em 01/02/2015 EN
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The plant phenol trans-resveratrol, which is mainly found in grape, displays a wide range of biological effects. A cell suspension culture was developed from calli of grape leaves of Vitis vinifera cv. Negramaro in order to study the bioproduction of resveratrol. The effects of a number of secondary plant metabolism elicitors, namely chitosan, methyl jasmonate, jasmonic acid, coronatine, and 12-oxo-phytodienoic acid, were tested on this cell suspension culture. The identification and quantification of stilbenes was achieved with high performance liquid chromatography, with both spectrophotometric and mass spectrometric detection. Of the tested elicitors, methyl jasmonate was the most effective in inducing the biosynthesis of approximately 4 mg g−1 dry weight (about 60 mg L−1) of resveratrol. Conversely, 12-oxo-phytodienoic acid, jasmonic acid, and coronatine were able to trigger the synthesis of approximately 20 mg g−1 dry weight (200–210 mg L−1) of viniferins. Taken together, our results show for the first time different modulatory effects of closely-related jasmonates on stilbene biosynthesis.

Polyphenol intake and mortality risk: a re-analysis of the PREDIMED trial

Tresserra-Rimbau, Anna; Rimm, Eric B; Medina-Remón, Alexander; Martínez-González, Miguel A; López-Sabater, M Carmen; Covas, María I; Corella, Dolores; Salas-Salvadó, Jordi; Gómez-Gracia, Enrique; Lapetra, José; Arós, Fernando; Fiol, Miquel; Ros,
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
EN_US
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Background: Polyphenols may lower the risk of cardiovascular disease (CVD) and other chronic diseases due to their antioxidant and anti-inflammatory properties, as well as their beneficial effects on blood pressure, lipids and insulin resistance. However, no previous epidemiological studies have evaluated the relationship between the intake of total polyphenols intake and polyphenol subclasses with overall mortality. Our aim was to evaluate whether polyphenol intake is associated with all-cause mortality in subjects at high cardiovascular risk. Methods: We used data from the PREDIMED study, a 7,447-participant, parallel-group, randomized, multicenter, controlled five-year feeding trial aimed at assessing the effects of the Mediterranean Diet in primary prevention of cardiovascular disease. Polyphenol intake was calculated by matching food consumption data from repeated food frequency questionnaires (FFQ) with the Phenol-Explorer database on the polyphenol content of each reported food. Hazard ratios (HR) and 95% confidence intervals (CI) between polyphenol intake and mortality were estimated using time-dependent Cox proportional hazard models. Results: Over an average of 4.8 years of follow-up, we observed 327 deaths. After multivariate adjustment...

Stilbenes from Deguelia rufescens var. urucu (Ducke) A. M. G. Azevedo leaves: effects on seed germination and plant growth

L?BO, L?via Trindade; SILVA, Geilson Alcantara da; FREITAS, Manolo Cleiton Costa de; SOUZA FILHO, Antonio Pedro da Silva; SILVA, Milton Nascimento da; ARRUDA, Alberto Cardoso; GUILHON, Giselle Maria Skelding Pinheiro; SANTOS, Lourivaldo da Silva; SANTOS,
Fonte: Universidade Federal do Pará Publicador: Universidade Federal do Pará
Tipo: Artigo de Revista Científica
ENG
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A biodiversidade Amaz?nica pode ser uma fonte de subst?ncias capazes de serem utilizadas no controle de plantas daninhas. Neste estudo relatamos o isolamento e a identifica??o de cinco estilbenos a partir das folhas do "timb? vermelho" (Deguelia rufescens var. urucu): 4-metoxilonchocarpeno (1); 3,5-dimetoxi-4?-hidroxi-3?-prenil-trans-estilbeno (2), lonchocarpeno (3), 3,5-dimetoxi-4?-O-prenil-trans-estilbeno (4) e pteroestilbeno (5). As subst?ncias 2 e 4 s?o novos produtos naturais, por?m 2 j? havia sido citada como produto de s?ntese. Foi avaliada a potencial atividade alelop?tica de 1, 2 e 4 sobre a germina??o de sementes e o crescimento da planta daninha Mimosa pudica. Os efeitos observados sobre a germina??o das sementes de M. pudica n?o variaram significantemente (p > 0,05) quando a an?lise da fitotoxidade foi realizada com as subst?ncias isoladamente, cuja inibi??o m?xima n?o ultrapassou 20%. A inibi??o mais intensa, quanto ao desenvolvimento da rad?cula e do hipoc?tilo, foi encontrada para o composto 4 (p < 0,05). Isoladamente, 4 causou efeito inibit?rio significativamente maior (p < 0,05) no desenvolvimento da rad?cula e do hipoc?tilo, do que 1 e 2. Quando testados aos pares, apresentaram antagonismo para a germina??o de sementes e sinergismo para o desenvolvimento da rad?cula e hipoc?tilo.; ABSTRACT: The Amazon biodiversity may provide plants whose chemical substances are capable of controlling weeds. In this study we report the isolation and identification of five stilbenes from the leaves of "timb? vermelho" (Deguelia rufescens var. urucu): 4-methoxylonchocarpene (1); 3...

Investigation of monomeric and oligomeric wine stilbenoids in red wines by ultra-high-performance liquid chromatography/electrospray ionization quadrupole time-of-flight mass spectrometry

Moss, R.; Mao, Q.; Taylor, D.; Saucier, C.
Fonte: John Wiley & Sons Ltd Publicador: John Wiley & Sons Ltd
Tipo: Artigo de Revista Científica
Publicado em //2013 EN
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RATIONALE: Stilbenoids are secondary plant metabolites responsible for the protection of multiple plant species including grape vine from bacterial and fungal infection. Red wine has been shown to be a major source of these compounds in the human diet, where they display an array of health benefits. Providing a more complete profile of the stilbenoids present in red wine, this study detects 41 stilbenoid compounds, 23 of which have never before been detected in red wine. METHODS: Red wine extracts were scanned using an ultra-high-performance liquid chromatograph coupled to a hybrid quadrupole time-of-flight mass analyzer. Multiple targeted MS/MS precursor ion scan experiments were performed using electrospray ionization operated in negative mode. Precursor ion masses were scanned for the monomeric and oligomeric stilbenoids, as well as modifications such as O-glycosylation, methoxylation and oxidation products of these compounds. Accurate mass precursor and characteristic product ions afforded partial structural elucidation and assignment of these compounds. RESULTS: A total of 41 (both known and novel) stilbenoids were detected in extracted red wine. In addition to the well-known monomeric stilbenes, several resveratrol-resveratrol homodimers (m/z 453.1344)...

Développement d'un tandem multicatalytique méthylénation - couplage de Heck et Approche synthétique de l'Hodgsonox

Bréthous, Lise
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
FR
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Cette thèse comprend deux parties distinctes, dans lesquelles seront décrits tout d’abord, le développement d’un procédé multicatalytique en un seul pot d’une réaction de méthylénation suivie d’un couplage de Heck, puis dans un second temps, une étude vers la synthèse de l’Hodgsonox. Le premier thème de la thèse correspond à la mise en place d’un procédé en un seul pot, basé sur la méthodologie de méthylénation catalysée par un métal de transition, développée au sein du groupe du Pr. Lebel, et sur des couplages de Heck. Différentes études de compatibilité des réactifs mis en présence sont abordées, ainsi que le choix des conditions optimales (Pd(OAc)2 et P(o-tol)3) pour la réalisation d’un tel système qui ne requiert aucun isolement du produit intermédiaire. Il a été démontré que la présence de triphénylphosphine en excès inhibe la réaction de couplage de Heck, ce qui a finalement orienté notre choix vers les sels de cuivre pour la catalyse de la réaction de méthylénation. Le tandem séquentiel a ensuite été appliqué à la synthèse de divers stilbènes, notamment des composés dérivés du Resvératrol, molécule d’intérêt thérapeutique pour les maladies cardiovasculaires...

The interaction with tubulin of a series of stilbenes based on combretastatin A-4.

Woods, J. A.; Hadfield, J. A.; Pettit, G. R.; Fox, B. W.; McGown, A. T.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /04/1995 EN
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A series of stilbenes, based on combretastatin A-4, were synthesised. A structure-activity study was carried out to characterise the interaction of these agents with tubulin. The substitution of small alkyl substituents for the 4'-methoxy group of combretastatin A-4 and the loss of the 3'-hydroxyl group does not have a major effect on the interaction with tubulin. trans-Stilbenes were shown to bind tubulin, but do not inhibit microtubule assembly. This work, together with previous studies, has been used to propose an idealised structure for a tubulin-binding agent of this type.

Ultraviolet-C and Induced Stilbenes Control Ochratoxigenic Aspergillus in Grapes

Selma, María Victoria; Freitas, Paula M.; Almela, Luis; González-Barrio, Rocío; Espín de Gea, Juan Carlos; Suslow, Trevor; Tomás Barberán, Francisco; Gil Muñoz, M.ª Isabel
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artículo Formato: 259768 bytes; application/pdf
ENG
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7 pages, 5 figures, 1 table.; This study investigated the efficacy of ultraviolet-C (254 nm) and induced stilbenes to inhibit Aspergillus carbonarius and Aspergillus tubingensis and control ochratoxin A production in grapes. In addition, the stilbene synthesis as a response to UV-C treatment and to infection of ochratoxigenic Aspergillus was compared. The initial microbial inactivation by a previously optimized UV-C illumination protocol for increasing trans-resveratrol content in grapes (50 W/m2, 40 cm, 60 s) was similar on undamaged and damaged grapes, achieving 1.2 and 1.3 log conidia/100 g reductions, respectively. After 5 days of storage at 22 °C, UV-C treatment and the stilbenes induced by UV-C inhibited ochratoxigenic Aspergillus growth in undamaged grapes. UV-C elicited the biosynthesis of trans-resveratrol, while microbial infection and tissue damage triggered the biosynthesis of trans-piceid. trans-Resveratrol was not synthesized as a consequence of ochratoxigenic Aspergillus contamination. However, when trans-resveratrol was synthesized by UV-C, it contributed to inhibiting the development of ochratoxin A producing aspergilli. Furthermore, UV-C treatment also contributed to decrease ochratoxin A production by ochratoxigenic aspergilli. Therefore...

Differential stilbene induction susceptibility of seven red wine grape varieties upon post-harvest UV-C irradiation

Cantos Villar, Emma; Tomás Barberán, Francisco; Martínez, Adrián; Espín de Gea, Juan Carlos
Fonte: Springer Publicador: Springer
Tipo: Artículo Formato: 259768 bytes; application/pdf
ENG
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6 pages, 2 figures, 2 tables.-- Online version published Aug 2003.; The stilbene induction capacity of the red wine grape varieties 'Tempranillo' (TEM), 'Cabernet Sauvignon' (CAS), 'Merlot' (MER), 'Syrah' (SYR), 'Monastrell' (MON), 'Garnacha' (GAR) and 'Cariñena' (CAR) exposed to post-harvest UV-C irradiation is reported for the first time. The induction of trans-piceatannol, trans-resveratrol and viniferins, among other stilbenes, was characterized using high-performance liquid chromatograph with diode-array and mass spectrometric detection (HPLC-DAD-MS-MS). All the wine grape varieties increased their resveratrol, piceatannol and viniferin content after UV-C treatment with the exception of the variety MON in which only piceatannol was induced. Other stilbenes such as astringin (piceatannol glucoside) or piceid (resveratrol glucoside) were induced to a lesser extent and only in some varieties. The stilbene induction capacity of grapes submitted to UV-C irradiation did not necessarily match the final corresponding maximum stilbene content reached in each variety. The total stilbene induction capacity of the grapes ranged from 2.4-fold (in MER) to 10.9-fold (in both CAS and CAR) with respect to untreated grapes (control). The total stilbene content (mg stilbene/100 g fresh weight...

Cyclodextrins and stilbenes as components of supramolecular structures

Cieslinski, Marta
Fonte: CSIRO Publishing Publicador: CSIRO Publishing
Tipo: Artigo de Revista Científica
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The use of cyclodextrins and stilbenes as components of supramolecular structures was discussed. Hermaphroditic molecules thermodynamically favor the formation of dimeric complexes and high oligomers might be formed when appropriate geometry is installed. In order to find application in nanotechnology, the ultimate aim was to be able to control the motion with application of external stimuli, such as heat or light. The cyclodextrin was found to move from one binding state to another upon application of an external stimulus.

Review: Quantitative Extraction and Analysis of Grape and Wine Proanthocyanidin and Stilbenes

Sun,Baoshan; Spranger,M. Isabel
Fonte: INIAV - DOIS PORTOS (Ex-Estação Vitivinícola Nacional) Publicador: INIAV - DOIS PORTOS (Ex-Estação Vitivinícola Nacional)
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2005 EN
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From the point of view of biological importance, proanthocyanidins (condensed tannins) and stilbenes (1,2-diarylethenes) are the two most important classes of polyphenols in grape and wine, which have attracted considerable attention of the international scientific community during the last fifteen years, due essentially to their potential beneficial health effects, related to their protective action towards cardiovascular disease and the oxygen free radical scavenger capacity. Numerous research works on proanthocyanidins and stilbenes have been published, but the majority of them have focused on the structural identification and biological activities of these compounds. Furthermore, less attention has been paid on their quantitative aspects and few analytical methods have been validated. This paper introduces briefly grape and wine proanthocyanidins and stilbenes and presents some works realized in our laboratory concerning quantitative extraction and analysis of these compounds.