Dissertations / Theses on the topic 'Stilbenoidi'
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1
Holst, Hans Christof. "Stilbenoide Sternsysteme Synthese und Eigenschaften /." [S.l. : s.n.], 2003. http://ArchiMeD.uni-mainz.de/pub/2003/0031/diss.pdf.
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Soomro, Shahid A. "Design, synthesis and photochemical studies of stilbenoid dendrimers." [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=975958569.
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Moss, Ryan Kurtis. "Development and validation of methods for the investigation of wine stilbenoids." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/50808.
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Stilbenoids are secondary plant metabolites responsible for the protection of 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.
The first goal of our study was to develop and validate a robust and selective method for quantification of the major stilbenoids in red and white wine using ultra-high-performance liquid
chromatography coupled with electrospray ionization/quadrupole time-of-flight mass
spectrometry (UHPLC-ESI-Q-TOF). Both isomers of resveratrol and piceid were quantified
externally using authentic standards, while piceatannol was quantified in trans-piceid
equivalents. Due to the minimal amount of sample preparation and the short method runtime,
results were obtained rapidly and with low expenditure of energy, chemicals, and labor.
The method was validated with respect to linearity, limit of detection (LOD), limit of
quantification (LOQ), accuracy, intra- and inter-day precision and stability. All six stilbene
monomers were quantified in 44 British Columbian wines; the highest total stilbene
concentration in an individual wine was 28.81 mg/L in Pinot Noir, while the average across all
wines was 8.49 ± 6.25 mg/L..
Another method was developed for separation, identification and semi-quantification of
all derivatives of resveratrol that are present in wine.
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), resveratrol-piceatannol heterodimers (m/z 469.1293) and piceatannolpiceatannol homodimers (m/z 485.1236) were detected. Modified dimers of resveratrol were also
detected. Multiple trimers of resveratrol (m/z 679.1978) were detected for the first time in red
wine, as well as some known and some novel stilbenoid tetramers (m/z 905.2604).
A solid-phase extraction (SPE) method was developed for quantification of the stilbenoid
oligomers in red wines. The monomers and oligomers in red wine from the Okanagan Valley
(Cabernet Sauvignon, Merlot and Pinot Noir) and Québec (Maréchal Foch, Marquette,
Sabrevois, St.Croix, and Frontenac) wines were semi-quantified as using this method. The
highest concentration of total stilbenoids was 10.67 mg/L in Pinot Noir with an overall average
of 3.32 ± 2.86 mg/L in all wines.Irving K. Barber School of Arts and Sciences (Okanagan)
Chemistry, Department of (Okanagan)
Graduate
4
Ressler, Daniel. "Synthesis of Resveratrol Ester Derivatives." Digital Commons @ East Tennessee State University, 2013. https://dc.etsu.edu/etd/1234.
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The goal of this research project was to synthesize derivatives of transresveratrol. In order for resveratrol to be activated and used by the body it needs to bind to Human Serum Albumin (HSA), a protein in blood plasma. The derivatives were synthesized to improve the ability of resveratrol to enter cells as well as improve their ability to bind to HSA. The three derivatives that were synthesized have converted one of the hydroxyl groups on resveratrol to an ether with a methylene chain terminated by a carboxylic acid. By varying the lengths of the methylene chain we varied the water solubility of the resveratrol derivative. This brought the research closer to the goal of determining how this would affect the binding ability to HSA. Currently three derivatives have been synthesized and purified once by column chromatography.
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Karpouk, Elena. "Photochemie von ungesättigten Sternverbindungen Wirt-Gast-Systeme bei stilbenoiden Dendrimeren /." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=971998450.
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Bhusaunahalli, Vedamurthy Maheswarappa. "Natural polyphenols as lead compounds in the synthesis of antitumor agents and other useful products." Doctoral thesis, Università di Catania, 2012. http://hdl.handle.net/10761/961.
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NATURAL POLYPHENOLS AS LEAD COMPOUNDS IN THE SYNTHESIS OF ANTITUMOR AGENTS AND OTHER USEFUL PRODUCTS
Abstract
Some polyphenol dimers, such as lignans, neolignans and stilbenoid lignans, because of their biological properties as well as their structural variety, are an attractive target for chemical synthesis or modification. These polyphenols may be considered lead compounds to obtain products with useful properties, for instance as possible antitumor agents. Thus, this three year research work has been oriented to the synthesis of new dimers, obtained by biomimetic oxidative coupling of natural polyphenols belonging to the stilbenoid and phenylpropanoid families, namely resveratrol or caffeic acid analogues. To this purpose we employed both chemical and enzymatic methods; in particular, metal-mediated reactions were used for the synthesis of nitrogenated lignans with a benxanthene core, whereas stilbenolignans were also obtained with laccase-mediated reactions. During this work, an unexpected enzymatic reaction afforded an hydantoin-related product and this result is also reported herein.
The results of this research are discussed mainly in chapter 2, where three sections are reported:
1) Biomimetic synthesis of stilbenolignans
2) Biomimetic synthesis of benzo[k,l]xanthene lignanamides
3) Enzymatic synthesis of hydantoin-related compounds
In each section, we have reported in detail the synthesis, structural determination, and mechanism of the formation of the products. The final goal of our project was to obtain a library of bioactive compounds to be addressed to biological evaluation with the aim to establish structure-activity relationships for a future optimization of the most promising products. The biological evaluation has been completed for the stilbenolignan group and it is in progress for the other compounds.
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Van, Cleve Shelley Marie. "Synthesis of a Resveratrol Glycinate Derivative." Digital Commons @ East Tennessee State University, 2011. https://dc.etsu.edu/etd/1312.
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Recently, the compound resveratrol has had media attention as an anti carcinogen. However, the bioavailability of resveratrol is low in the human system due to its hydrophobic nature. Therefore, it must be administered in high dosages to be effective. A plethora of derivatives have been synthesized that have the potential of resveratrol but sadly share low bioavailability. The first effort of this research was an attempt to produce a more hydrophilic ester of resveratrol. Failing this, the final product was synthesized using a glycine derivative to produce 4-[(1E)-2-(3,5-diacetyloxyphenyl)ethenyl]phenyl N-[(1,1-dimethylethoxy)carbonyl]-glycinate.
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Jing, Stanley Mofor. "Synthesis of Resveratrol Esters and Aliphatic Acids." Digital Commons @ East Tennessee State University, 2011. https://dc.etsu.edu/etd/1382.
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Resveratrol (RV) is a naturally occurring phytoalexin of the stilbenoid family produced by some plant species, and present in grape skin, peanuts, and red wine. It has been found to exhibit anti-cancer, anti-inflammatory, anti-viral, anti-aging, cardio protective, and anti-oxidant properties. Bioavailability is a huge setback that limits the potentials of RV. As a result, efforts have been made to design and synthesize RV esters and aliphatic acids in an attempt to increase its bioavailability, solubility in water, and possibly improving its biological activities. Resveratrol esters, 3,5,4'-triacetyloxystilbene (2) and Methyl 1,1',1''- (3,4',5-stilbenyl)-1,6-hexanedioate (3) have been synthesized. Compound 3 is a new compound, synthetic yield is 88%, and purity is above 95% based on NMR integration. Both 2 and 3 are good candidates for biological evaluation. 3 was used as a precursor in the synthesis of resveratrol aliphatic acid, 8-(3',5'-dihydroxylstilbene-4''-oxy)-3,6-dioxocotanoic acid (9). First, 2 was hydrolyzed to resveratrol diester, 3,5-diacetyloxystilbene (4). Mitsunobu reaction of 4 and methyl 8-hydroxy-3,6-dioxooctanoate (7) was then carried out to afford methyl 8-(3',5'-diacetyoxystilben-4''-oxy)-3.6-dioxooctanoate (/5), which was then hydrolyzed to afford 9 in total 43.6 % yield. Structures of all newly synthesized compounds were confirmed by 1H and 13C NMR spectroscopy.
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Bisson, Jonathan. "Développements méthodologiques en chromatographie de partage : application aux stilbénoïdes." Thesis, Bordeaux 2, 2012. http://www.theses.fr/2012BOR22006/document.
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Les stilbénoïdes, sont des composés phénoliques majoritairement issus du règne végétal. La Vigne par l’intermédiaire du vin et du raisin est la principale source alimentaire de stilbènes. La mise en évidence de leur rôle dans les mécanismes de défense des plantes et leurs activités biologiques, y compris sur l’Homme, en font un sujet d’étude en plein essor. L’un des objectifs de cette thèse a été de développer un ensemble de stratégies à la fois analytiques et préparatives utilisant la Chromatographie de Partage Centrifuge (CPC) pour l’étude et l’obtention de ces molécules. Dans un premier temps, nous avons développé une approche de couplage entre cette technique et un spectromètre à Résonance Magnétique Nucléaire (RMN) par l’intermédiaire d’un système d’Extraction sur Phase Solide automatisé (EPS). Dans un second temps, nous avons mis au point un ensemble de méthodes et d’approches séparatives permettant d’obtenir ces composés. Nous avons, grâce au développement d’une méthodologie de dosage de solvants par spectrométrie RMN, étudié une gamme dérivée d’une gamme très utilisée en CPC, l’ARIZONA. Nous avons montré que ces systèmes dérivés, peuvent être utilisés au travers de stratégies d’élution telles que des pas et des gradients afin d’optimiser les séparations. L’une des finalités de notre travail est d’offrir des méthodes permettant d’obtenir ces composés dans des quantités et des qualités suffisantes pour pouvoir constituer une chimiothèque interne au laboratoire pouvant prétendre à s’intégrer dans la Chimiothèque Nationale. Une dernière partie fait état du développement d’outils informatiques, dont la création d’une base de donnée Libre pour les chercheurs en Substances NaturellesStilbenoids are phenolic compounds mostly found in the vegetable kingdom. Vine through wine and grape is the main source of stilbenes in the human diet. The involvement of these compounds in plants resistance mechanisms and their diverse biological activities, including on the human health are continuously highlighted. Making this topic a fast-growing one. One of the objectives of this thesis has been to develop a whole set of analytical and preparative strategies using Centrifugal Partition Chromatography (CPC) in order to study and obtain these molecules. Over a first phase, we developed a hyphenated approach between this technique and Nuclear Magnetic Resonance (NMR) through an automated Solid Phase Extraction (SPE) system. Then, we developed a set of separative methods and approaches with the aim of obtaining these compounds. Then, we carried out the development of a solvent quantifications methodology using NMR spectrometry. This allowed us to study a spin-off scale of a widely-used solvent systems collection called ARIZONA. We showed that these systems are good candidates for different elution strategies using steps and gradients with the aim to optimize separations. One of our purpose was to provide methods for effective and efficient purification of these compounds. This would allow, together with a lab-scale compounds library, their integration into the Chimiothèque Nationale, a nationwide chemical library. Last part accounts for computer tools development, including the creation of a Free database system for Natural Substances researcher
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Lambert, Carole. "Étude du rôle des stilbènes dans les défenses de la vigne contre les maladies du bois." Thesis, Bordeaux 2, 2011. http://www.theses.fr/2011BOR21910/document.
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Les maladies du bois de la vigne, par exemple le syndrome de l’esca et l’eutypiose, sont dues à des champignons qui se développent dans le xylème et dégradent les tissus ligneux. Elles sont en recrudescence depuis une vingtaine d’année dans tous les vignobles du monde. A ce jour, aucun traitement curatif n’est disponible alors que ces maladies engendrent généralement la mort de la plante. L’étude des relations hôte-parasite et notamment celle des réponses de défense de plante, est nécessaire pour la compréhension et le développement de nouvelles stratégies de lutte. Parmi les molécules de défense de la vigne, les stilbènes sont connus pour leur forte activité antifongique.Notre travail, basé sur des approches biochimiques et moléculaires apporte de nouvelles données sur le rôle potentiel des stilbènes en tant que molécules de défense contre les maladies du bois. Nous avons identifié et quantifié les stilbènes majoritaires des tissus ligneux de V. vinifera, évalué la sensibilité des agents de maladie du bois à l’effet antifongique de ces stilbènes et suivi leur éventuelle induction suite à l’inoculation d’agents de maladie du bois. Nous avons souligné l’importance des oligomères de stilbènes dont l’activité antifongique est élevée et montré qu’ils sont fortement induits dans le bois inoculé par un champignon pathogène de la famille des Botryosphaeriaceae. La comparaison des réponses de défenses entre des cépages tolérants et sensible, a montré que les cépages tolérants répondent globalement plus fortement et plus rapidement que le cépage sensible à une élicitation par un filtrat de milieu de culture d’un agent de l’escaGrapevine wood diseases, as esca syndrome and eutypiosis, are worldwide afflictions. They are due to xylem inhabiting fungi that cause the decay of woody tissues and finally the death of the plant. No curative treatment has been successfully developed until now. Studying grapevine-wood disease pathogen interaction is a prerequisite to the development of protection strategies. Phenolics, particularly stilbenoids, are antimicrobial molecules involved in the resistance of grapevine to fungal pathogens. Our work, based on biochemical and molecular approaches, reveals new data on the possible role of stilbenoids in grapevine defence against trunk diseases. We identified and quantified major stilbenoids of woody canes from V. vinifera. These compounds, especially stilbenoid oligomers, displayed in vitro antifungal activity against trunk disease agents and were induced in cuttings inoculated with an agent of the Botryosphaeriaceae family. We also compared the defence response of susceptible or tolerant cultivars to wood decay based on an elicitation assay with a culture filtrate of an esca pathogen. Defence responses of tolerant cultivars were more effective than those of the susceptible cultivar
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Gali, Meghanath. "Synthesis of Small Molecule Inhibitors of Janus Kinase 2, Phosphodiesterase IV, GABAA and NMDA receptors: Investigation of Mcmurry, Mannich and Chemoenzymatic Strategies." Scholar Commons, 2011. http://scholarcommons.usf.edu/etd/3110.
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Stilbenoids possess a wide range of biological properties such as, anticancer, antiplatelet aggregation, antiestrogenic, antibacterial, antifungal and antiatherogenic, etc. Owing to these therapeutic values, a great deal of attention attracted in the synthesis of derivatives of stilbenes. During the course of the study, G6 a novel stilbenoid was discovered, through high throughput screening, to be a potent inhibitor of mutated JAK2-V617F. The mutated JAK2 variant has been implicated in various myeloproliferative disorders (MPDs) including polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF) has been targeted by therapeutics. Chapter 2 describes the synthesis of analogs of the stilbenoid G6 and N-substituted stilbenes bisoxazines by utilizing Mcmurry reaction and Mannich condensation methods. The main emphasis of this work is to develop novel stilbenoids as inhibitors of JAK2-V617F mutated Jak2 enzyme in Human erythroleukemia cells (HEL) since this mutation is discovered in the majority of patients with myeloproliferative disorders (MPDs). Using Mcmurry reaction, five novel trans-hydroxystilbenes have been synthesized from carbonyl compounds. Subsequently using Mannich coupling with five secondary amines and five primary amines, 25 novel stilbenoids and 9 novel N-substituted stilbene bisoxazines have been synthesized. In HEL cell assay, 8 stilbenoid analogues have been identified as potent inhibitors of Jak2 enzyme.
Chapter 3 describes the modification of ketamine structurally for the synthesis of novel analogues to study for their agonist activity at GABAA receptors and antagonist activity at NMDA receptors. Ligand gated ion channels like GABAA and NMDA receptors are membrane-embedded proteins at synaptic cleft which controls intercommunication among neurons and plays an important role in motor control activity, learning. GABAA receptors are responsible for inhibitory action potentials while NMDA receptors are responsible for excitory action potentials. Ketamine, known as dissociative anesthetic, produces profound analgesia at low doses to a unique cardiovascular stimulation and a cataleptic state at higher doses with dose dependent side effects like vivid dreams, disruptions of cognitive functions. The main emphasis of this work is the synthesis of novel analogues of ketamine by transforming carbonyl group in ketamine to imine functionality with small to bulkier groups and to identify an analogue of ketamine which is highly potent in its activity at the both GABAA and NMDA receptors and improved clinical actions. Studies of analogues activity against GABAA subtypes α6Β2δ, α1Β2γ2 receptors and NMDA subtypes NR1/2A, NR1/2B, NR1/2D receptors have been described.
Chapter 4 describes the formal synthesis of (±)-Rolipram and the chemoenzymatic synthesis of -aryl--lactone, a Rolipram analogue. The key steps, Pd catalyzed arylation of diethylmalonate and the efficient use of selective acylation of 1, 3-diol entails the formal synthesis of (±)-Rolipram. The regioselective deacylation of Β-aryl-1, 4-diacetate by lipase Pseudomonas Sepacia entails the formation of Β-aryl-γ-lactone. The efficient use of various methods including halogen exchange, Heck arylation of diethylmaleate and lactonization for the synthesis of Β-aryl-γ-lactone have been discussed. The present work provides an efficient and general route to γ-lactones.
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Bayach, Imene. "Non-covalent interactions in natural products." Thesis, Limoges, 2014. http://www.theses.fr/2014LIMO0050/document.
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Les polyphénols naturels forment des complexes non-covalents dans lesquels le π-stacking et les liaisons hydrogène jouent un rôle clé dans la stabilisation. Les calculs DFT incluant la dispersion (DFT-D), la description des processus d'agrégation non-covalente de produits naturels devient fiable. Dans ce travail, les méthodes DFT-D sont appliquées à i) la compréhension de la biosynthèse stéréo- et régio-sélective des oligostilbenoïdes, ii) la prédiction de l'agrégation des antioxydants naturels au sein de la membrane bicouche lipidique, qui pourrait rationaliser la synergie de la vitamine E, la vitamine C et polyphénols dans leur action antioxydante, et iii) la modulation des propriétés optiques de dérivés de chalconesNatural polyphenols form non-covalent complexes in which π-stacking and H-bonding play a key stabilizing role. The dispersion-corrected DFT calculations have paved the way towards reliable description of aggregation processes of natural products. In this work, these methods are applied at i) understanding of stereo- and regio-selective oligostilbenoids biosynthesis; ii) predicting natural antioxidant aggregation within lipid bilayer membrane, which may allow rationalizing the synergism of vitamin E, vitamin C and polyphenols in their antioxidant action; and iii) modulating optical properties of chalcone derivatives
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Houillé, Benjamin. "Valorisation de coproduits de la viticulture, les sarments de vigne, comme source de polyphénols à activité fongicide." Thesis, Tours, 2015. http://www.theses.fr/2015TOUR3807.
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Ce travail porte sur la valorisation de sarments de vigne comme source de polyphénols bioactifs. Après purification d’oligomères du resvératrol et hémi synthèse d’analogues du resvératrol, l’activité antifongique de ces molécules a été testée. Le 3,5-diméthoxyresvératrol a montré des activités intéressantes sur douze espèces du genre Candida. Pendant le stockage des sarments, une forte augmentation en E-resvératrol et E-picéatannol a lieu de façon thermo dépendante et l’expression des gènes PAL, C4H et STS participent à la biosynthèse de novo du E-resvératrol. Une infection par le mildiou au vignoble pendant la période de croissance modifie à la fois la composition et la répartition spatiale des stilbénoïdes dans les sarments. L’analyse métabolomique ciblée par UPLC-MS couplée à une analyse PLS-DA permet de discriminer les sarments selon leur génotype et de déterminer des métabotypes. La distance biochimique observée correspond à la distance génétique inter cépage. Ces résultats démontrent le potentiel antifongique des stilbènoïdes et permettent d’identifier quelques facteurs clés influençant la composition phytochimique des sarments de vigneThis work aims at grape cane valorization as a source of bioactive polyphenols. After purifying E-resveratrol oligomers and obtaining E-resveratrol analogues through semi-synthesis, the antifungal activity of the compounds was evaluated. The 3,5-dimethoxyresveratrol exhibited interesting activity against twelves Candida species. During post-pruned grape cane storage, a strong and temperature dependent increase in E-resveratrol and E-piceatannol was observed and the expression of PAL, C4H, 4CL and STS genes contributed to a de novo biosynthesis of E-resveratrol. Downy mildew infection in vineyard during the growing season modified both the composition and the spatial distribution of stilbenoids in grape canes. UPLC-MS-based targeted metabolomics coupled to multivariate statistical analysis discriminates grape canes according to their genotypic origin and determines metabotypes. The observed biochemical distances between genotypes corresponded to genetic distances. Finally, results highlight the antifungal potential of stilbenoids and several key factors affecting the phytochemical composition of grape canes
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Olusegun-Osoba, Elizabeth Oluwakemi. "Strategies towards the synthesis of 4-(3-methyl-but-1-enyl)-3,5,3',4'-tetrahydroxystilbene (arachidin-1) and resveratrol analogues." Thesis, University of Hertfordshire, 2015. http://hdl.handle.net/2299/17118.
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Stilbene phytoalexins such as resveratrol, 1, and the arachidins, including arachidin-1,2, are naturally synthesised by peanut (Arachis hypogaea) plants. The peanut phytoalexins are polyphenolic compounds consisting of a stilbene backbone, with a number of derivatives also possessing a prenyl moiety. These distinctive phytoalexins have gained attention, as they exhibit various biological activities, for instance arachidin-1, 2, has been reported to be more potent than resveratrol, 1, in the inhibition of lipopolysaccharide-induced expression of cyclooxygenase-2 (COX-2) and COX-2 mRNA, in vitro at doses that were low in cytotoxicity. Additionally the various arachidins have recently been shown to exhibit their anti-inflammatory properties, through the inhibition of a number of inflammatory mediator pathways. In this work, various routes into the synthesis of arachidin-1, 2, are described, via use of the Horner-Wadsworth-Emmons (HWE) reaction. Three different methodologies were explored, the first approach involving silyl ether (TIPS or TBDMS) protected benzaldehydes, proved unsuccessful due to cleavage of the silyl ether protecting groups, in basic and/or acidic conditions. This led to an alternative approach, whereby formation of the stilbene backbone proceeded via the regioselective demethylation of an acetal in the presence of sodium metal, subsequent electrophilic substitution using iodomethane and finally acetal hydrolysis of the acetal, gave the isolated aldehyde in moderate yield (52 %). Coupling of the aldehyde with the substituted benzylphosphonate, via the HWE reaction gave the desired trans-stilbene in good yield (86 %), however incorporation of the prenyl side chain proved to be challenging via the Wohl-Ziegler bromination. Further adaptation of the aforementioned route, whereby alkylation using diethyl iodomethylphosphonate, enabled the incorporation of the prenyl moiety and the subsequent construction of the trans-stilbene backbone, gave the 4-(3-methyl-but-1- enyl)-3,5,3',4'-tetramethoxystilbene, 3, albeit in poor yield (47 %). The final step involving demethylation using BBr3 gave arachidin-1, 2, also in poor yield (30 %), nevertheless this approach has been proved to be a successful route for the total synthesis of arachidin-1, 2, however optimised studies are required in order to obtain the desired compound in quantitative yields. Synthetic analogues of resveratrol, 1, are also known for their biological activities, including anti-inflammatory and chemopreventative properties. Recently, the anti-proliferative activity of a number of stilbenesulfonamides, against the National Cancer Institute's 60 (NCI-60) human tumour cell line has been reported. Furthermore, the anti-inflammatory effects of novel heterocyclic methylsulfone and sulfonamide analogues, via inhibition of the COX-2 protein have also been published, however both synthetic routes described require a total of six or seven steps, from the sulfanilamide and are limited to the synthesis of primary sulphonamides (SO2NH2). In this work, an efficient three step synthesis has been designed and successfully implemented, proceeding via chlorosulfonation of diethyl benzylphosphonate, to form the sulfonyl chloride intermediate. Aminolysis of the sulfonyl chloride intermediate was then performed, using a range of primary, secondary and cyclic alkyl amines, as well as aromatic amines; including ammonia, dimethylamine, morpholine and diphenylamine. Finally, formation of the stilbene backbone with various substituted aldehydes, via the HWE reaction offered a short, versatile and alternative route to the synthesis of novel primary, secondary and tertiary trans-stilbene benzenesulfonamides and heterocyclic analogues, in yields of 42 - 100 %. The activity of a selection of the synthesised stilbene benzenesulfonamides was evaluated against the human lung adenocarcinoma epithelial cell line (A549). Amongst the compounds tested, analysis of the data showed that the novel analogue, 4, was found to be the most potent compound, with a GI50 of 0.1 μM. Comparison with the previously published data found analogue, 4, to be approximately 500-fold more potent than the lead compound resveratrol, 1, (GI50 = 51.64 μM) and approximately twice as potent than 5-fluorouracil (GI50 = 0.189μM), a chemotherapy drug used to treat various forms of cancer 8. Overall, these results demonstrate that the total synthesis of trans-arachidin-1, 2, can be achieved via a five step methodology. A versatile route to the synthesis of novel stilbene benzenesulfonamides has also been successfully achieved, amongst the compounds synthesised one appears to show promising anticancer activity, and warrants further investigation (i.e. in vitro studies using other cancer cell lines, and the synthesis of additional compounds using analogue, 4, as a lead compound).
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Auberon, Florence. "Stilbénoïdes et dérivés glucosyloxybenzyliques d’acides organiques isolés d’orchidées tropicales : études chimiques et biologiques de Cyrtopodium paniculatum (Ruiz & Pav.) Garay et Arundina graminifolia (D.Don) Hochr." Thesis, Strasbourg, 2016. http://www.theses.fr/2016STRAF045.
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Nous avons porté une attention particulière à 2 marqueurs chimiotaxonomiques de la famille botanique des orchidées, les stilbénoïdes et dérivés glucosyloxybenzyliques d’acides organiques, et les avons recherchés dans deux espèces tropicales. L’investigation phytochimique de Cyrtopodium paniculatum (Ruiz & Pav.) Garay a permis l’isolement de 35 stilbénoïdes dont 12 nouvellement décrits. L’évaluation de leur activité cytotoxique in vitro sur la lignée cellulaire cancéreuse UG-87 montre que seuls les stilbénoïdes dimères semblent aptes à induire une perturbation de l’intégrité cellulaire. Nous avons également exploré la composition chimique d’Arundina graminifolia (D.Don) Hochr. De ses parties aériennes, 9 stilbénoïdes (dont 2 nouvelles structures ont été isolés) ainsi que des 7 nouveaux dérivés hydroxybenzyliques de l’acide (R) 2-benzylmalique, les arundinosides. De ses parties souterraines, plus de 40 arundinosides ont également pu être identifiés. Nous avons finalement évalué le potentiel cytoprotecteur de stilbénoïdes et arundinosides d’ A. graminifolia sur lignée cellulaire PC12, sans qu’aucune activité relevée n’ait été concluanteThe aim of the study was focused on two chemotaxonomic markers of the family Orchidaceae, namely stilbenoids and the glucosyloxybenzyl derivatives of organic acids. We specifically explored these two chemical families in two tropical orchid species. The chemical investigation of Cyrtopodium paniculatum (Ruiz & Pav.) Garay led to the isolation of 35 stilbenoids, including 12 newly described compounds. Their cytotoxic activity on UG-87 cancer cell line was evaluated. The result obtained demonstrated that stilbenoids dimers were the only compounds capable of disturbing the cellular integrity. In parallel, we explored the chemical composition of Arundina graminifolia (D.Don) Hochr. From its aerial parts, 9 stilbenoids (including 2 newly described ones) together with 7 new (R) glucosyloxybenzyl 2-benzylmalate derivatives, the arundinosides, were isolated. From its underground parts, over 40 arundinoside-like compounds have also been identified. The cytoprotective evaluation of stilbenoids and arundinosides against beta-amyloid induce toxicity on PC12 cells was evaluated, however, no significant result was obtained from the biological evaluation
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Čáková, Veronika. "Contribution à l'étude phytochimique d'orchidées tropicales : identification des constituants d'Aerides rosea et d'Acampe rigida : techniques analytiques et préparatives appliquées à Vanda coerulea et Vanda teres." Phd thesis, Université de Strasbourg, 2013. http://tel.archives-ouvertes.fr/tel-00997451.
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L'analyse de la composition chimique de deux orchidées de la sous-tribu des Aeridinae, Aerides rosea Lodd. ex. Lindl. & Paxton et Acampe rigida (Buch.-Ham. ex Sm.) P. F. Hunt, a été menée en ayant recours à des techniques de couplages et grâce à une stratégie de déréplication. Dix dérivés phénanthréniques ont ainsi été identifiés dans les tiges d'A. rosea, dont deux nouvellement décrits. Quatre stilbénoïdes, trois dérivés d'acides phénoliques et quatre esters d'acide cinnamique ont été identifiés dans les tiges d'A. rigida. Nous avons également effectué des dosages de traceurs dans différents échantillons de deux représentants de la tribu des Vandeae : Vanda teres (Roxb.) Lindl. et Vanda coerulea Griff. ex. Lindl., afin de mettre en évidence d'éventuelles variations de composition en fonction des facteurs environnementaux et du stade de croissance végétative. Enfin, nous avons mis au point des conditions d'isolement préparatif par chromatographie de partage centrifuge afin de purifier des marqueurs biologiques préalablement identifiés dans les tiges de Vanda teres : trois glucospyranosyloxybenzyl - malates ainsi que leur précurseur biosynthétique.
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Malacarne, Giulia. "Caratterizzazione del profilo metabolico e trascrizionale di una popolazione di Vitis spp. segregante per la resistenza a Plasmopara viticola." Doctoral thesis, 2007. http://hdl.handle.net/10449/32772.
Full textAbstract:
Downy mildew, caused by the oomycete Plasmopara viticola (B. et C.) Berl. et De Toni, is a common disease of grapevine. Although the exact mechanisms by which grapevine cells regulate the disease incidence upon P. viticola infection have largely lain undiscovered until now, it is known that a hypersensitive response (HR) occurs in American Vitis species. The HR to P. viticola was also associated with metabolic and transcriptional events, such as deposition of lignin and other phenolics, accumulation of stilbene phytoalexins, and activation of genes encoding for pathogenesis related proteins (Jeandet et al., 2002, Pezet et al., 2004, Kortekamp, 2006). Aim of this project was to test a possible correlation between the variability in the resistance to the fungus, in the stilbene content and in the gene expression by a targeted metabolite and transcriptional profiling of selected individuals of a population from Merzling (V. vinifera x V. rupestris x V. lincecumii) x V. vinifera ‘Teroldego’. The phenotypic characterization of the response to the fungus within the population allowed us to classify the individuals in classes from total resistance to total susceptibility. The HPLC-DAD-MS analysis performed on infected leaves collected at 6 days post infection (dpi) with the pathogen lead to three main results: it confirmed the stilbene accumulation upon P. viticola infection, it selected a 17% of individuals accumulating the five major viniferins in grapevine and it pointed our attention to the presence of a few oligostilbenes and stilbenoids still undiscovered, whose characterization was performed in the same project. The comparative transcriptional analysis was conducted on resistant and susceptible individuals by a combined approach of i) cDNA-Amplification Fragment Length Polymorphism (AFLP) and ii) oligo-array techniques. The first analysis lead to the isolation of more than 300 transcripts specifically modulated in a totally resistant offspring with respect to Merzling parental and to the discovery that these transcripts can be clustered in two groups according to their kinetics of activation. The “early modulated” were differentially expressed during the first 12 hours post infection, the “late modulated” were differentially expressed starting from 48 hpi. The second analysis allowed further investigation of these genes picking which ones were specific or common between resistant and susceptible individuals.
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Bangani, Vuyisile. "Homoisoflavonids and stilbenoids from Scilla species." Thesis, 1998. http://hdl.handle.net/10413/3648.
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Bulbs of Scilla natalensis Planch, Scilla nervosa (Burch.) Jessop, Scilla dracomontana Hilliard and Burt and Scilla kraussii Bak. (Hyacinthaceae) were investigated. The plants are widely used by the local African people for a variety of ailments that inflict them and their livestock. Plant material was harvested in different localities i.e. KwaZulu-Natal (KZN) and Mpumalanga (Mpl). The bulbs have been found to contain homoisoflavonoids and stilbenoids. Ten homoisoflavonoids and two stilbenoids were isolated. Of the ten
homoisoflavonoids isolated, nine were of the 3-benzyl-4-chromanone type while one was a 3-benzylidene-4-chromanone. Four of the 3-benzyl-4-chromanones were found to be novel compounds while others were recognised as having been reported before from
other genera within the family Hyacinthaceae viz., Eucomis and Muscari. The 3-benzylidene-4-chromanone type compound isolated was also found to be a known compound. The stilbenoids, on the other hand, are reported for the first time in this genus although they seem to have a wide distribution in the plant kingdom. The structures of the isolated compounds were elucidated using spectroscopic methods.Thesis (M.Sc.)-University of Natal, Durban, 1998.
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Holst, Hans Christof [Verfasser]. "Stilbenoide Sternsysteme : Synthese und Eigenschaften / Hans Christof Holst." 2003. http://d-nb.info/967586402/34.
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MAŠKOVÁ, Hana. "Antivirotické účinky stilbenoidů proti klíšťaty přenášeným patogenům in vivo." Master's thesis, 2018. http://www.nusl.cz/ntk/nusl-376087.
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This study was focused on antiviral effects of stilbenoids against a virus transmitted by ticks. The cell viability of selected cell line cultures in the presence of various concentrations of stilbenoids was determined using the MTT assay. Similarly, the mixed effect of other known antiviral substances and stilbenoids was studied using the MTT assay. Both the prophylactic effects of stilbenoids on the infected culture cell lines and the effect on viral replication were examined. The viral titres from samples were determined using plaque assay. Some of the experiments were performed also in vivo using laboratory mice.
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Chung, Ping-Chen, and 鍾秉真. "The effects of peanut stilbenoids on HL-60 cell line." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/78438899024656727438.
Full textAbstract:
碩士國立臺灣大學
醫學檢驗暨生物技術學研究所
96
Stilbenoids are phytoalexins produced by plants under attack by pathogens such as fungi. Previous sutdies have demonstrated that stilbenoids have bioactivities such as anti-oxidation, anti-inflammation, cancer chemoprevention and anti-carcinogenic effect. In this study, resveratrol (RSV), arachidin-1 (Ara-1), arachidin-3 (Ara-3), and isopentadienylresveratrol (IPD) were isolated from peanuts. RSV, Ara-1 and Ara-3 display cytotoxic effect on HL-60, and Ara-1 is the most toxic. Further study showed that Ara-1 treatment on HL-60 cells caused loss of mitochondrial membrane potential (MMP), caspases activation, and changes in cell cycle distribution. Ara-3 treatment on HL-60 cells caused loss of MMP and cell membrane integrity as well as caspases activation. These results suggested that Ara-1 and Ara-3 are potential anticancer agents that induced cancer cell apoptosis. Ara-1 and RSV are cytotoxic to proliferating cells, HL-60, but did not affect on nonproliferating human peripheral blood mononuclear cells. Furthermore, Ara-1 was found to inhibit the activity of topoisomerase II in vitro, but showed no significant difference in cytotoxicity between HL-60 and Topo II defective HL-60/MX2 cells. Topoisomerase II inhibition may not be involved in the mechanisms of apoptosis induction by Ara-1 in HL-60 cells. These results indicate that Ara-1 and Ara-3 are potential anti-cancer agents.
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Paul, Shiby. "Inhibition of colon carcinogenesis by stilbenoids and mechanisms of action." 2010. http://hdl.rutgers.edu/1782.2/rucore10001600001.ETD.000052141.
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Linhartová, Lenka. "Molekulární podstata lékových interakcí -interace konstitutivního androstanového receptoru s vybranými stilbenoidy." Master's thesis, 2019. http://www.nusl.cz/ntk/nusl-397858.
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Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Lenka Linhartová Supervisor: Prof. PharmDr. Petr Pávek, Ph.D. Title of diploma thesis: Molecular mechanisms of intractions - interactions of constitutive androstane receptor with selected stilbene compounds Constitutive androstane receptor (CAR), member of nuclear receptors family, is a major regulator of gene expression of phase I and II enzymes metabolizing endobiotics and xenobiotics. Changes in its activity can lead to pharmacokinetic drug interactions, ineffective treatment or higher toxicity of drugs simultaneously administered with CAR ligands. Recently another effects of this receptor, especially in homeostasis of bile acids, lipids and glucose have been discovered and CAR is now considered as a potential drug target for the treatment of metabolic diseases. Stilbenes represent a small group of plant polyphenols with typical 1,2-diphenylethylene nucleus. The most famous member is resveratrol, which has attracted great attention thanks to its antioxidant, anti-inflammatory, antiproliferative and cardioprotective effects. Others stilbene compounds such as pterostilben, piceatannol or pinosylvin have shown similar health beneficial effects as well. The aim of this diploma thesis was...
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Soomro, Shahid A. [Verfasser]. "Design, synthesis and photochemical studies of stilbenoid dendrimers / Shahid A. Soomro." 2005. http://d-nb.info/975958569/34.
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CHU, MEI-YI, and 朱美嬑. "The Anti-Oxidant Mechanism Of Resveratrol And Stilbenoid On Human Keratinocyte." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/7j2h5p.
Full textAbstract:
碩士長庚科技大學
健康產業科技研究所
107
In many literatures, resveratrol (Res) and stilbenoid have many effects (eg, as anticancer agents, platelet anticoagulants, anti-inflammatory, anti-allergic, etc.), which may be due to their molecular structure, and these structures are capable of binding to many biomolecules. Ampelopsin C 、Ampelopsin F、Polydatin they are all Res and stilbenoid. But their antioxidant effect on the skin is still unknown.In this study, we wanted to investigate whether Res and its derivatives have antioxidant capacity in skin cells, and further explore its mechanism. First, the anti-oxidant effect of Res and stilbenoid was examined in vitro using scavenge DPPH• assay. In cell experiments, we detected the effect of Res and stilbenoid on keratinocyte viability. using MTT asssy. Next we analyzed the antioxidant ability of Res and stilbenoid at a safe dose by H2DCFDA staining. Further, we used Western blotting analyses to explore whether Res and stilbenoid produce antioxidant enzymes to achieve antioxidant capacity. We used pharmacological inhibitors, immune fluorescence staining, separation proteins from nuclear and cytosol to demonstrate their molecular mechanisms, It was found that all Res and stilbenoid could induce the expression of heme oxygenase-1 (HO-1) and catalase for 24 hours; maximum expression was reached in 48 hours. In addition, Ampelopsin-induced anti-oxidant enzymes might through ATPase, AMPK, MAPK and downstream transcription factors in HaCaT cell.
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Jui-Shien, Hsu, and 徐睿仙. "Biosynthesis of the Secondary Metabolites of Stilbenoids by Cotyledon-removed Peanut Embryos." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/7fymp8.
Full textAbstract:
碩士國立嘉義大學
食品科學系研究所
107
During germination of peanut seeds, stilbene compounds can be detected in the embryos including germs, hypocotyls and roots. In this study, with an attempt to understand mechanism for whether the detected stilbenoids are biosynthesized in the cotyledons and transported to other embryo parts, cotyledons were removed from the 4-day germinated peanut sprouts. The cotyledon-removed embryos were subjected to various physical damages including knife or scissor cutting and machine slicing for 1 cycle and incubation under ambient temperature for 3 days. During incubation, aliquots of sample were taken at the 0th, 1st and 3rd day of incubation and subjected to extraction with methanol solution and followed by determination of trolox equivalent antioxidant capacity (TEAC). The determined TEAC values of knife or scissor cut treated peanut embryos are slightly higher than that of machine slicing ones. In consideration of manual knife and/or scissor cuttings are labor-intensive and time consuming and difficult to apply for mass production. The peanut embryo cut by a rotary slicing machine was chosen for further development. The peanut embryos were subjected to repeatedly machine slicing for 1, 3 and 5 cycles and then incubated under ambient temperature with artificial aeration for 72 h. Aliquots of sample were taken every 24 h and subjected to extraction and HPLC analysis. Based on the HPLC chromatograms, all peanut embryos were able to biosynthesize the major peanut stilbenoid compounds, namely, arachitin-1 (Ar-1), arachitin-3 (Ar-3), isopentadienylresveratrol (IPD) and arahypin-5 (Ap-5). Generally, contents of ar-1, IPD and Ap-5 for all treatments increased with an increase of incubation time and reached the highest points at 48 h and decreased slightly at 72 h of incubation. When various batches of 5-cut peanut embryos were subjected to incubation for 48 h and followed by extraction and HPLC analysis, the obtained peanut stilbenoid profiles varied in a limited range. For further peanut stilbenoid compositional analysis, the 80% extracts after dilution were loading on a SPE column and then clean-up with 20% methanol and fractionated by eluting with 60 and 80% methanol solutions. Based on the obtained HPLC chromatograms, SPE fractionation was effective to separate peanut stilbenoids. In further, the peanut embryos were dried and pulverized into powders and extracted with 80% methanol and subjected to MPLC fractionation and HPLC analysis of each collected tube solution. It is of merit that under appropriate medium pressure liquid chromatography (MPLC) operation, Ar-1, Ar-3 and Ap-5 could be isolated in a single collected tube and assumptive structural identification after vacuum drying and 1H NMR analysis. As generalized, the cotyledon-removed peanut embryos still bear capability in stilbenoid biosynthesis and the capabilities were enhanced after physical wounding. MPLC is of efficacy in effective separation and purification of the biosynthesized stilbenoids and provides an advanced tool for structural and properties characterization.
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鄭雅今. "Induction, analysis and identification of stilbenoids in callus of peanut(arachis hypogaea L.)." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/19887981506432094318.
Full textAbstract:
碩士國立嘉義大學
農學研究所
91
Abstract It is known that the seeds and roots of peanut possess substantially amount of resveratrol, a phytoalexin compound in some plants. This interests us to find wether the tissue-cultured callus of peanut also contain resveratrol and other stilbenoids. In case it contains stilbenoids, we also would like to know how to produce high stilbenoids callus, which in turn is used as a new resource for resveratrol. Therefore, the main goal of this study is to generate stilbenoids contained peanut callus. To achieve the purpose, there are three important topics in this study must to be solved. The first is the development of an analytical method for resveratrol in peanut callus. The second is the identification of the other resveratrol-like compounds in peanut callus. And the third is developing methods to induce and scale up the production of resveratrol- like compounds. Quite a number of chromatographic techniques including HPLC and GC have been reported to analyze resveratrol in variety of samples. However, almost all the sample preparation, separation, and detection conditions are just only feasible for some specific sample matrices. Here we developed a reversed-phase HPLC-UV-Fluorescence method for routinely analyzing resveratrol-like compounds in peanut callus. The solvent system is consisted of a 35 min gradient from 20 to 90% acetonitrile with 1% formic acid in water at a flow rate of 0.8 mL/min. The eluted species are detected sequentially at 306nm and 343nm excitation/ 395nm emission by coupled UV-fluorescence detectors. By using electrospray ionization (ESI) ion trap mass spectrometry, we identified piceatannol and 4-isopentenyl resveratrol alone with resveratrol in the peanut callus. Also we found there are many peaks other than the three mentioned stilbenoids in the UV-fluorescence chromatograms. These signals might be the responses form those unidentified stilbenoids in peanut callus. As a preliminary study, we did not detect resveratrol signal in intact callus samples. Horever, formation of stilbenoids in callus was induced by physical methods including UV radiation, pressing treatment, and cutting treatment. Besides, the calluses are cultured under static and suspension conduction, respectively. For 20 hrs of static culture, the highest amount of resveratrol in cutting treated callus is 2100 ng/g. And the amount of piceatannol is 2250 ng/g. Moreover, for 3 days of suspension culture, the highest amount of resveratrol in cutting treated callus reaches to 8657 ng/g. And the amount of piceatnnol in cutting treated callus also reaches to 5500 ng/g after culturing by suspension for 9 days.
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Lin, Li-Lian, and 林麗蓮. "Investigation of stilbenoids in Arachis hypogaea, Polygonum cuspidatum, Ampelopsis brevipedunculaata, and Vitis thunbergii." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/13205493047722851454.
Full textAbstract:
碩士國立嘉義大學
農學研究所
94
trans-Piceatannol and trans-resveratrol have been proved to have a close relation with antioxidative, anti-inflammatory, and anti-carcinogenesis effects in the tested animal models. In the first part of this study, the traditional Taiwanase herbs including Polygonum cuspidatum, Ampelopsis brevipedunculaata and Vitis thunbergii were used as the samples to evaluate a simple chromatography method with simultaneous extraction and quantitatively analytical approaches. The mobile phase for the reversed-phase chromatography composed of H2O+FA/ACN. Analysis of the samples by coupling with UV-fluorescence detectors, the linear regression coefficients (r2) for trans-resveratrol and trans-piceatannol were found to be 1.0000 and 0.9998, respectively. By spiking of the authentic compounds into the methanol extract of the callus of Arachis hypogaea, the recovery for trans-piceatannol and trans-resveratrol were 101% and 93%, respectively. The incorporation of the standard compounds into the leaves extract of V. thunbergii led us to obtain the recovery yields of 96.5% ± 1.10% and 95.0% ± 13.7% for trans-piceatannol and trans-resveratrol, respectively. Moreover, the efficiency has been greatly improved by the liquid nitrogen extraction or lyophilized then extracted with MeOH. The relative standard deviations (RSD) for trans-piceatannol and trans-resveratrol in intraday or interday were found to be less than 6%. Experimental results also showed that the limitation of detection (LOD) were 0.82 ng/mL and 0.81 ng/mL for trans-piceatannol and trans-resveratrol, respectively, and the limitation of quantization (LOD) for these two compounds were 1.63 ng/mL and 2.76 ng/mL, respectively, indicating that it is a reliable, sensitive, and accuracy method for the quantization of very low amount of trans-piceatannol and trans-resveratrol. The second part of this study is focused on the analysis of trans-stilbenoid content of methanolic extracts of P. cuspidatum, A. brevipedunculaata and V. thunbergii. The results showed that all these samples contained trans-piceatannol and trans-resveratrol. In the case of V. thunbergii, low temperature storage would enhance the content of both compounds. The major work in the third part of this study is to investigate the induction biosynthesis of trans-stilbenoid by A. hypogaea. Using aseptic seedling of A. hypogaea as the experimental sample, we found that the biosynthesis of trans-stilbenoid did not occurred in the lack of any environmental stress. After UV irradiation or bacterial infection, the trans-stilbenoid could be detected in the aseptic seeding of A. hypogaea. Among the induction, the highest contents of 182.85 ng/g and 6434.2 ng/g for trans-piceatannol and trans-resveratrol were observed in the aseptic seeding of A. hypogaea infected with fungui and incubated at a visible light condition. Additionally, the observation of trans-stilbenoid content of fungus-infected A. hypogaea, we found that the concentrations of trans-piceatannol and trans-resveratrol reached to a maximum after 248 hr- and 224 hr-infection, respectively.
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Schulz, Andrea [Verfasser]. "Synthese und Photochemie von Dendrimeren mit stilbenoiden Chromophoren / Andrea Schulz." 2006. http://d-nb.info/979908485/34.
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Karpouk, Elena [Verfasser]. "Photochemie von ungesättigten Sternverbindungen : Wirt-Gast-Systeme bei stilbenoiden Dendrimeren / Elena Karpouk." 2004. http://d-nb.info/971998450/34.
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Luo, Chiau-Wen, and 羅喬文. "Inhibition of aggregated Aβ-induced PC-12 cells apoptosis by edible plant material extracts and stilbenoids." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/99483059663155123193.
Full textAbstract:
碩士國立臺灣大學
食品科技研究所
96
Alzheimer''s disease (AD), the major cause of dementia, is a neurodegenerative disorder associated with impairment in memory and cognitive function. AD is characterized pathologically by the presence of senile plaques (amyloid plaques), and neurofibrillary tangles (NFT). β-amyloid peptide (Aβ) has been proposed to play an important role in the pathogenesis of AD. Deposits of Aβ are found in the brains of patients with AD and are one of the pathological hallmarks of the disease. Many studies have shown that aggregated Aβ can induce caspase-dependent apoptosis and death by oxidative stress and increase intracellular calcium levels in cultured neurons. The aim of my study is to investigate the antioxidative activities and neuroprotective effects of some edible plant extracts and stilbenoids. The antioxidative potency was evaluated by DPPH radical scavenging activity and trolox equivalent antioxidant capacity (TEAC). The neuroprotective activity was evaluated in vitro in the “Aβ-induced cell death of rat pheochromocytoma (PC-12) cells” model system. Among the different samples (mulberry, roselle and the embryo of Nelumbo nucifera Gaertn. seed extracts), methanol extract of the embryo of Nelumbo nucifera GAERTN. seed (Nn-M) showed better antioxidative activity and also higher inhibitory effect against Aβ25-35 –induced cytotoxicity. Therefore, Nn-M was fractionated into n-hexane, ethyl acetate, n-butanol and aqueous fractions. The n-butanol fraction of Nn-M was found to have the best inhibitory effect against Aβ1-40 –induced cytotoxicity. Among stilbenoids, stilbene glycoside purified from Polygonum multiflorum Thunb. (PM-SG) has better inhibitory effect against Aβ25-35 –induced and Aβ1-40 –induced cytotoxicity than pterostilbene. The mechanism of the possible protective action of PM-SG and n-butanol fraction of Nn-M was further investigated. Results showed that Aβ1-40 signficantly increased ROS level, intracellular [Ca2+] and caspase-3 activity, and also signficantly decreased mitochondrial membrane potential and glutathione content in PC-12 cells. PM-SG and n-butanol fraction of Nn-M showed a significant reduction of the elevated ROS, intracellular [Ca2+] and caspase-3 activity and also replenished the loss of mitochondrial membrane potential and glutathione content induced by Aβ1-40. This study concludes that PM-SG and n-butanol fraction of Nn-M have potential neuroprotective ability against Aβ-mediated cell damage.
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Juan, Yi-Chen, and 阮怡禎. "The action mechanisms of stilbenoid derivative ugonstilbene A extracted from Helminthostachys zeylanica (L) Hook in rabbit platelets." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/39737331761831244240.
Full textAbstract:
碩士國立陽明大學
藥理學研究所
92
Helminthostachys zeylanica, a terrestrial fern of the Ophioglossaceae family, also known as Daodi-Ugonn in Taiwan and Tukod-langit in Malay language. The dry rhizomes were traditionally used to remove blood stasis and promote blood circulation. The folkloric therapies in Southeastern Asia also use them to treat cough in tuberculosis, asthma and poisonous snakebites patients. Stilbenoid can be extracted form various plants and previous studies have revealed its bioactivities in lipid peroxidation inhibition, cyclooxygenase inhibition, calcium channel blocking and radical-scavenging. Ugonstilbene A, a new trans- stilbene compound belong to polyphenolic phytoestrogens, was isolated from the rhizomes of Helminthostachys zeylanica (L.) Hook. To understand the mechanisms of ugonstilbene A, that designed a series of experiments using rabbit platelets. The results showed the compound dose-dependently inhibited washed rabbit platelets aggregation induced by platelet-activating factor (PAF), U46619 (analog of thromboxane A2) or arachidonic acid (AA) with IC50 values of 11.73 ± 6.26, 12.9 ± 4.7, 6.24 ± 0.64 □M, respectively. LDH assay excluded the cytotoxicity of this compound. Pretreatment with ugonstilbene A could reduce PAF- U46619- AA-mediated intracellular calcium elevation. Moreover, calcium flux was directly reduced by this compound including intracellular store release and extracellular influx, but not through inducing cAMP and cGMP levels of rabbit platelets. On the other hand, ugonstilbene A significantly decreased PAF-induced IP3 level and PKC translocation, implicating that this compound might inhibit PLC activity. Immunoprecipitation revealed the coupling between G protein and PLC was modulated by this compound. Platelet activity could reversed by removing ugonstilbene A, indicated its action sites were on the membrane. Furthermore,. the membrane fluidity was enhanced by this compound. The inhibition of MDA formation revealed its bioactivity of lipid peroxidation in AA pathway. Both the inhibitions of TXA2 and PGE2 indicated its COX inhibitory role. ABTS and DPPH assay confirmed the antioxidant effects of ugonstilbene A. This study not only confirmed that this stilbenoid compound has the above mentioned abilities but also provided medical evidences of traditional medicine.
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Yu-HsuanShih and 史育璇. "Antibacterial effects and the mechanisms of stilbenoid compounds alone or combined with silver nanoparticles against foodborne pathogens." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/p5j4c4.
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Chang, Yong-Ling, and 張永霖. "Studies of Stilbenoid Stability of Peanut Sprout Products and Used as an Ingredient for Processing of Functional Foods." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/x9v796.
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碩士國立嘉義大學
食品科學系研究所
106
Peanut is an important economical crop worldwide with diverse product patterns for consumption. Peanut seeds contain high quality proteins, along with other healthy micronutrients. After processing and rendering the unique peanutty aroma, the processed peanut contained foods are one of the world's most popular consuming products. In recent years, peanut polyphenols have received increasing attention, in particular stilbenoids comprising resveratrol (Res). Many studies have shown that these stilbenoids are potent antioxidants, bearing anti-inflammatory, active in prevention of cardiovascular disease and exhibiting anti-cancer antivities. Stilbenoid biosynthesis of stilbenoids as phytoalexins during peanut seed germination was significantly enhanced and then the related research and product developments have attracted public attention with general interest. In this study, the main purpose was addressed on stability characterization of the stilbenoids in the peanut sprout products and feasibility of further use of the products as ingredients for processing of functional foods. Stilbenoid stability was measured manily based on quantitative changes of Res, arachidin-1 (Ar-1), arachidin-3 (Ar-3) and isopentadienylresveratrol (IPD). Peanut kernels were subjected to germination and then sliced and spread on a try for drying in an air-forced oven. The appropriate dry-heat-treated slices were ground into peanut sprout butter and/or subjected to solvent defatting and pulverizing in preparation of bio-activated peanut sprout powder (BPSP) and both were frozen stored (- 20oC) for later use. Aliquots of BPSP samples in a series of crucibles were heated at 120 to 200oC for 30 min and followed by stilbenoid analysis. It was observed that cotents of Ar-1 were slightly increased at 120 and 140oC, while other stilbenoid contents were decreased as heat temperature rose. The appropriate dry-heat-treated slices were ground into peanut sprout butter and/or subjected to solvent defatting and pulverizing in preparation of bio-activated peanut sprout powder (BPSP) and both were frozen stored (- 20oC) for later use. When a thin layer of BPSP was irradiated with 254 nm UV light for 4 h, contents of the stilbenoids changed in an ignored range. When BPSP was further extracted with 80% methanol and the extract was heated at 100oC for 2 h, stilbenoid contents decreased slightly while as heating time increased a further gradual decrease of the contents was detected. Irradiation of the extracts with UV light, Res contents decreased slightly at the early stage and then decreased gradually with time of irradiation, while contents of other stilbenoids decreased gradually with an increase of irradiation time. When the extracts were dissolved in buffer solutions with varied pH values, the stilbenoids were comparatively stable in acidic (pH 2-6) condition and unstable in alkaline environments, particularly being very unstable at pH 12. When the peanut sprout butters were subjected to gamma ray irradiation for various doses, total viable counts decreased with an increase of irradiation dose and complete sterilization was achieved at doses of 10-30 KGy. Under these irradiation doses, the stilbenoid profile was not changed. Based on the fact that BPSP is rich in protein and bears novel amino acid composition, it was used in partial substitution of wheat flour for preparation of cake and biscuit products. After baking at relatively high temperature (160 to 190oC) to produce the final products and following by taking samples for stilbenoid analysis and oxidative stability assessment, the added BPSP stilbenoids were not decreased and antioxidative stabilities of the products were obviously improved. As generalized, with an attempt to use peanut sprout powder and/or peanut sprout butter in dietary supplement development and used as an ingrident for processing of functional foods, it is strongly suggested to avoid over-heating, long time exposure of UV light irradiation and direct interaction with alkaline material. Through these novel processes, it is of efficacy to minimize changes of the stilbenoids and maintain the unique health-benefited functional activities to meet the general desire of the consumers.
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Deng, Jie-Ren, and 鄧傑仁. "Antioxidative and antibacterial activities of stilbenoids extracts from peanuts and their effects on quality of sausage products during storage." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/55357594615397049605.
Full textAbstract:
碩士國立嘉義大學
食品科學系研究所
98
Stilbenoids in peanut kernel have potent bio-activities, such as resveratrol, piceatannol, archidin-1, archidin-2, archidin-3, etc. Some studies indicated that stilbenoids have anti-inflammation, inhibition of tumor growth and prevention of thrombosis. In this study, to evaluate applicability and potential product development of stilbenoids, the stilbenoids were extracted from after sliced hurt peanut kernels by 60 % ethanol. First parts of study to assessed antioxidant properties by DPPH free radical scavenging activity, reducing power and trolox equivalent antioxidant capacity (TEAC); and antibacterial properties by inhibition zone, minimum inhibitory concentration (MIC) assay and minimum bactericidal concentration (MBC) assay. As the results, the peanut stilbenoids have does-dependence in DPPH scavenging activity. When the concentration reached to 200 μg/mL, the scavenging activity was 79.77 %. In reducing power and TEAC, the absorbance at 700 nm was 0.59 and 0.60 μmol trolox/ mg, respectively. These results showed that peanut stilbenoids is a powerful antioxidant. Otherwise, peanut stilbenoids have susceptible inhibition on Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Salmonella typhimurium at 7000 μg/mL. The MIC on B. subtilis, S. aureus, E. coli and S. typhimurium was 62.5, 31.25, 62.5 and 125 μg/mL, respectively. The result showed that stilbenoids have potent antimicrobial activity could inhibit bacteria growth in low concentration. Second parts of this study were to evaluate the storage quality of Frankfurt and Chinese-style at ambient (25 ℃) and refrigerated (4 ℃) temperature, when adding 100, 2000 and 7000 μg/g of peanut stilbenoids. The sample was collected for analyses of total plate count, Coliform group, pH value, Hunter L, a, b value, 2-thiobarbituric acid and volatile basic nitrogen at ambient and refrigerated temperature during 0, 2, 4, 6 and 8 days and 0, 10, 20, 30 and 40 days, respectively. The results showed that in all treatment groups, the total plate count, Coliform group and VBN were increased with the storage time, and have significant difference (p＜0.05) compared to control. In pH value, all treatment groups were decreased during storage. In coloring difference test, all treatment groups were become darker and have lower L and b value. However, a value in Chinese-style sausage was increased, but decreased in Frankfurt sausage with the storage time. In TBA value, adding peanut stilbenoids at 7000 μg/g was significantly decreased, but all treatment groups were decreased only at 6th and 20th day in ambient and refrigerated temperature storage. In conclusion, stilbenoids from peanuts is a good source of antioxidant compounds, and could inhibit the pathogens growing. Furthermore, when added in meat products, stilbenoids could inhibit the growth of microorganisms and lipid oxidation. So it’s a good material of natural antioxidant and preservative.
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Hsieh, Wan-Yu, and 謝琬喻. "Anti-oxidative and anti-aging effects of several extracts of flowers and fruits as well as stilbenoids in Caenorhabditis elegans model." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/84840001044238270777.
Full textAbstract:
碩士國立臺灣大學
食品科技研究所
97
Aging is a progressive phenomenon of losing physiological function, behavior and cognitive ability over time. Previous studies have pointed out that oxidative stress is an important factor that causes aging. Therefore, some previously shown antioxidative materials were chosen, including water extract of Longan flower (Dimocarpus longan Lour.) (L-W), water extract of mulberry (Morus alba Linn.) (M-W), water extract of roselle (Hibiscus sabdariffa Linn.) (R-W), water fraction from ethanol extract of embryo of Nelumbo nucufera Gaertn.(N-E-W), stilbene glycoside from Polygonum multiflorum Thunb.(PM-SG) and pterostilbene. The objective is to investigate the anti-aging ability of these materials in the Caenorhabditis elegans model. The first part of this study was the chemical in vitro antioxidative experiments, including DPPH free radicals scavenging assay, trolox equivalent antioxidant capacity assay, oxygen radical absorbance capacity assay, reducing power assay and total polyphenols analysis. Results showed that L-W, PM-SG and pterostilbene had excellent activities followed by N-E-W, M-W and R-W. The second part of this study was the cellular antioxidant activity assay. The concentrations of each sample used in the assay were determined according to the cytotoxicity of each sample on Hep G2 cell. Results showed that L-W had the best cellular antioxidant activity with EC50 value 25.51 ± 2.17 μg/mL, followed by PM-SG (EC50 = 211.35 ± 34.11 μg/mL), N-E-W (EC50 = 457.83 ± 34.33 μg/mL) and M-W (EC50 = 776.66 ± 28.20 μg/mL). At 500 μg/mL R-W still did not have apparent activity while the cytotoxicity of pterostilbene was too high to express its antioxidant activity. Compared with the results of chemical antioxidant experiments, there were large differences in the activities of PM-SG and pterostilbene, indicating that the cellular antioxidant activity of these two compounds were influencesd by the structure. The third part of this study was the anti-aging tests in C. elegans model. We first investigated the lifespan prolonging effects of different samples. Results showed that only PM-SG、L-W and N-E-W had apparent anti-aging activities, with greatest degree of lifespan extention of 15.8%, 17.1% and 15.5%, respectively. Compared with the results of chemical antioxidant experiments, only samples exhibiting cellular antioxidant activities demonstrated anti-aging effects. Further examination of the effects of PM-SG、L-W and N-E-W on age-related changes of physiological processes, the results showed that PM-SG, L-W and N-E-W did not influence the self-fertile reproductive span, but did delay the decrease of pharyngeal pumping rate. This finding indicated that the lifespan prolonging effects of the three samples were not via influencing reproduction ability. On the other hand, since pharyngeal pumping rate had already been proved as one of the aging index, the finding of pharyngeal pumping rate test can be another evidence of the anti-aging ability of these samples. In addition, experiments to test if PM-SG, L-W and N-E-W are helpful to worms to resist the environmental pressure were also conducted, and the results showed that PM-SG, L-W and N-E-W can improve the survival rate of worms under thermal-stress, with greatest degree of lifespan extention of 46.8%, 53.6% and 32.3%, respectively. Only PM-SG and L-W, however, are helpful to worms to resist the oxidative-stress from H2O2, with greatest degree of lifespan extention of 81.7% and 113.7%, respectively. We speculated that the oxidative-stress was too high in this system, so that N-E-W with less antioxidant activity, can not express its antioxidant ability. In summery, samples, which showed better in vitro antioxidant activity, seemed to be the more effective ones in anti-aging tests in C. elegans model as well. This indicated that antioxidant activities correlate closely to anti-aging effects.