Resveratrol monomers

Mattivi F, Reniero F and Korhammer S. 1995. Isolation, characterization, and evolution in red wine vinification of resveratrol monomers. J Agric Food Chem 43(7)1820-1823. 

I-B group Oligostilbenes are polymerized directly from resveratrol monomers but do not contain any oxygen heterocyclic ring in their structures, such as ampelopsis D (21) [11]. Until now, 20 oligomers of this group have been found in plants. 

The H and I3C NMR data for the majority of the resveratrol dimers are presented in Tables (3) and (4), respectively. The data presented in these tables represent the typical range of chemical shift values and coupling constants that are encountered with all known resveratrol oligomers. Since most resveratrol oligomers can be considered as a dimer to which additional resveratrol monomers are fused (i.e. the trimer, leachianol D (34b), is the dimer pallidol fused with a third resveratrol moiety), these tables can be used to quickly help identify which structural moieties may be present in a new resveratrol oligomer. 

The presence of and relationship between trans- and cis-resveratrol monomers in the varietal wines from Dalmatia (Croatia), produced according to the Croatian appellation of origin system, were reported [19]. Standard methods of analysis for general wine components were used for a preliminary control of the selected wines. Resveratrol monomers in wine were measured by HPLC. Significant differences... 

Nicolaou and coworkers completed the enantioselective synthesis of these two natural products molecules through a short and equally efficient route (12 steps from commercially available material with the 4% overall yield) involving a series of cascade reactions and novel skeletal rearrangements [107b]. This unique route commenced with a CBS asymmetric reduction of ketone 288 that is easily generated from the resveratrol monomer (Scheme 10.55). The chiral benzylic alcohol 289 was obtained in 85% yield and 95% ee in the presence of one equivalent of catecholborane and catalytic amount of (/ )-(+)-2-methyl-CBS-oxazaborolidine. This newly formed C8a center would be served as a chiral source by which other stereocenters within the architectnre... 

Structures of CHS complexed with different Coenzyme A (CoA) thioesters and product analogs (i.e., naringenin and resveratrol) demonstrate that the active site is buried within an interior cavity located in the cleft between the upper and lower domains of each monomer (Fig. 12.3). Considering the complexity of the reaction... 

Stilbenes can also occur in oligomeric and polymeric forms, so-called viniferins. They are induced by oxidative polymerization of the monomer resveratrol through the activity of a peroxidase (Jean-Denis et al. 2006). Figure 9C.7 shows the biosynthesis of trans-s-mmfcxm. 

Fig. (1). Numbering of resveratrol (A) and (-)-E-viniferin (B) stilbene monomer is numbered respectively and the different units are distinguished by a, b, c, etc as an example, the numbering of 1 and 3 are shown in Fig. (1).

Dinan L. reported that three resveratrol trimers, suffruticosols A (100), B (101), C (102), and one monomer cis resveratrol from Paeonia suffruticosa are active as ecdysteroids (antagonists (EDso) 10-50 pM vs. 5xlO 8pM of 20-hydroxyecdyson), but inactive as agonists in the Drosophila melanogaster BII cell bioassay for ecdysteroids agonists/ antagonists [75]. 

The resveratrol oligomers are composed of a diverse assemblage of polyphenolic compounds derived from the trihydroxystilbene monomer resveratrol (1). Previously, in a review by Sotheeswaran and Pasupathy [7], the authors proposed a simple dichotomous classification scheme for categorizing these compounds based on a single structural feature. Under... 

Amyloid formation by TTR involves dissociation of the tetramer species to give a monomer. The same pathway is followed upon denaturation by urea, so the stability of the four proteins was studied by urea denaturation. Resveratrol, a fluorescent molecule, binds to the tetramer and can be used to monitor its concentration. These were measured at a different pH to the amyloid formation (pH 7), and at that pH the dissociation rates were similar to the wt rate for each Cys 10 variant. 

Within the grapevine, V. vinifera, including all parts of the plant and cell cultures, there are a httle over 60 known stilbenoids. However, the majority of these have not been identified as wine constiments. Of the total known V. vinifera stilbenoids, 17 are monomers, all resveratrol and piceatannol derivatives, with eight having been identified in wine. The majority of the stilbenoids are dimers, with 24 dimers known in the plant, but just 9 of these have been reported in wine. In addition to these dimers, there are six trimers in V. vinifera-, none have been identified in wine. While 16 tetramers are known V. vinifera plant part constituents, only one, hopeaphenol, has been foimd in wine [21]. 

In the berry, stilbenoids are produced primarily in the skin and to a lesser extent, the seeds. The stilbenoid monomers, E-resveratrol and E- and Z-piceid (Fig. 73.1) are... 

HPLC-MS has now become the analytical method of choice for the quantitation of stilbenoids in the grapevine and wine. Buiarelli et al. developed a method for the quantitation of several stilbenoid monomers E and Z forms of resveratrol, piceid, piceatannol, and astringin) in 19 red and 3 white Italian wines by HPLC-MS-MS using a triple quadrupole mass spectrometer without the need for sample preparation [53]. The detection limits were about 50 ng mL for all these monomers. 

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