Plants resveratrol

Stilbenes have a 1,2-diphenylethylene as their basic structure (C6-C2-C6). Resve-ratrol, the most widely known compound, contains three hydroxyl groups in the basic structure and is called 3,4, 5-trihydroxystilbene. In plants, piceid, the glucoside of resveratrol, is the major derivative of resveratrol. Stilbenes are present in plants as cis or trans isomers. Trans forms can be isomerized to cis forms by UV radiation (Lamuela-Raventos and others 1995). 

Condensation of coumaric acid with malonic acid yields the basic chalcone and stilbane skeletons (see Fig. 3.6). Stilbenes are found in most vascular plants, where they exhibit fungicidal and to a lesser extent antibiotic properties. They function as both constitutive and inducible defense substances. Some stilbenes inhibit fungal spore germination and hyphal growth, whereas others are toxic to insects and parasitic nematodes (round-worms). They also possess antifeeding and nematicide properties in mammals. For example, resveratrol (a stilbene in red wine) suppresses tumor formation in mammals. 

LANZ T., TROPF, S., MARNER, F.J, SCHRODER, J., SCHRODER, G., The role of cysteines in polyketide synthases site-directed mutagenesis of resveratrol and chalcone synthases, two key enzymes in different plant-specific pathways, J. Biol. Chem., 1991, 266, 9971-9976. 

Resveratrol has a long history. It was initially isolated from the roots of white hellebore in 1940. No one paid much attention. In 1963, it was isolated from a plant used for centuries in traditional Japanese and Chinese medicine. Again, this did not attract much attention. The story got a lot hotter in 1992 when the presence of resveratrol in red wine was suggested to be associated with the cardioprotective effects of red wine. 

PKSs are characterized by their ability to catalyze the formation of polyketide chains from the sequential condensation of acetate units from malonate thioesters. In plants they produce a range of natural products with varied in vivo and pharmacological properties. PKSs of particular note include acridone synthase, bibenzyl synthase, 2-pyrone synthase, and stilbene synthase (STS). STS forms resveratrol, a plant defense compound of much interest with regard to human health. STS shares high sequence identity with CHS, and is considered to have evolved from CHS more than once. ° Knowledge of the molecular structure of the CHS-like enzymes has allowed direct engineering of CHS and STS to alter their catalytic activities, including the number of condensations carried out (reviewed in Refs. 46, 51, 52). These reviews also present extensive, and superbly illustrated, discussions of CHS enzyme structure and reaction mechanism. 

Using the technique of activity-guided chromatographic isolation, it is possible to generate many structurally novel bioactive plant secondary metabolites, and examples have been provided in this chapter of plant secondary metabolites with potential anticancer or potential cancer chemopreventive activity, comprised by compounds representative of the chal-cone, flavanone, flavone, furocoumarin, isoflavone, lignan, oligostilbenoid (resveratrol... 

Burns J, Yokota T, Ashihara H, Lean MEJ, Crozier A. 2002b. Plant foods and herbal sources of resveratrol. J Agric Food Chem 50 3337-3340... 

Resveratrol-3-O-p-D-glucoside is called piceid. Resveratrol is a naturally occurring phytoalexin ( defender of the plant ) which is produced in response to an injury, such as mechanical trauma, ultraviolet light, and infection by pathogenic microorganisms, especially fungi, providing means for defense [Bertelli et al., 1995 Baolin et al., 2004 Bak et al., 2006 Baur et al., 2006]. It is formed via a condensation reaction between three molecules of malonyl CoA and one molecule of 4-coumaroyl CoA [Soleas et al., 1997], Resveratrol synthase facilitates this condensation reaction, which also produces four... 

Polygonum cuspidatum, a weed used in Chinese and Japanese medicine, is one of the first plants identified to extract resveratrol and is one of the richest... 

Hain R, Bieseler B, Kindi H, Schroder G, Stocker R. 1990 Expression of a stilbene synthase gene in Nicotiana tabacum results in synthesis of the phytoalexin resveratrol. Plant Mol Biol 15 325-335. 

Schubert R, Fischer R, Hain R, Schreier PH, Bahnweg G, Ernst D, Sandermann HJr. 1997. An ozone-responsive region of the grapevine resveratrol synthase promoter differs from the basal pathogen-responsive sequence. Plant Mol Biol 34 417-426. 

Hall D, de Luca Y. 2007. Mesocarp localization of a bi-functional resveratrol/hydro-xycinnamic acid glucosyltransferase of Concord grape (Vitis labrusca). Plant J 49 579-591. 

Hipskind JD, Paiva NL. 2000. Constitutive accumulation of a resveratrol-glucoside in transgenic alfalfa increases resistance to Phoma medicaginis. Molec Plant Microbe Interact 13 551-562. 

Langcake P. 1981. Disease resistance of Vitis spp. and the production of the stress metabolites resveratrol, -viniferin, a-viniferin and pterostilbene. Physiol Plant Pathol 18 213-226. 

Pezet R, Gindro K, Viret O, Spring J-L. 2004. Glycosylation and oxidative dimerization of resveratrol are respectively associated to sensitivity and resistance of grapevine cultivars to downy mildew. Physiol Molec Plant Pathol 65 297-303. 

Sotheeswaran S, Pasupathy V. 1993. Distribution of resveratrol oligomers in plants. Phytochem 32 1083-1092. 

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