Procyanidin B2

The effects of catechin, epicatechin, procyanidin B2, caffeic acid, / -coumaric acid, myricetrin, and quercetrin on the color intensity and stability of malvidin 3-glucoside at a molar ratio of 1 1 under conditions similar to red wine were evaluated. " Flavan 3-ols appeared to have the lowest protective effects and flavonols the highest strong color changes were visually perceptible. " In the complexation of malvin chloride and natural polyphenols, flavonol glycosides by far exerted the best protector effect. ... 

Fig. 2.114. RP-HPLC profiles of ACTs and SEC fractions (fr.) of ACTs. Each lyophilized sample was dissolved in water (1 mg/ml), and analysed by RP-HPLC. Upper chromatogram RP-HPLC profile of ACTs. Lower chromatograms with fraction numbers RP-HPLC profiles of SEC fractions of ACTs. The numbers of identified peaks in each chromatogram are (1) procyanidin B1 (PB1), (2) (+)-catechin, (3) procyanidin B2 (PB2), (4) procyanidin Cl (PCI), 5 (—)-epicatechin (EC). AU means relative absorbance units (at 280 nm). For details on the RP-HPLC conditions see text. Reprinted with permission from A. Yanagida et al. [253].

Fig. 2.115. Mass chromatograms of catechin monomers (m/z 289) and procyanidin oligomers (dimer through hexamers m/z 577 to 1729). C, ( + )-catechin, EC, ( — )-epicatechin, and PB2, procyanidin B2 as identified by the retention times of authentic standard. Reprinted with permission from J. Wollgast et al. [256].

Fig. 3.9 ESI mass spectrum of the dimer-rich fraction from Fig. 3.8c showing the procyanidin B2 peak (this eluted at 16.4 min after reverse-phase HPLC separation)...

FIGURE 2.11 The structures of the procyanidin dinners prominent in (from top to bottom) grape juice (procyanidin Bl), apple juice (procyanidin B2), and beer (procyanidin B3 and prodelphinidin B3). 

FIGURE 5.8 Mass fragmentation patterns of malvidin 3-glucoside-procyanidin B2 3 -gallate adducts. 

Kozikowski, A.P., Tuckmantel, W., and George, C., Studies in polyphenol chemistry and bioactivity. 2. Establishment of interflavan linkage regio- and stereochemistry by oxidative degradation of an 0-alkylated derivative of procyanidins B2 to (R)-(—)-2,4-diphenylbutyric acid, J. Org. Chem., 65, 5371, 2000. 

In general, the biological evaluation of hypericin in various test models is limited by its poor water solubility. It was shown in in vitro as well as in vivo studies (18,78) that the water solubility of hypericin was remarkably enhanced in the presence of procyanidins or flavonol glycosides of SJW extract. In a recent pharmacokinetic study in rats, it was shown that procyanidin B2 as well as hyperoside increased the oral bioavailability of hypericin by approximately 58% (B2) and 34% (hyperoside) (Fig. 5) (19). Procyanidin B2 and hyperoside had a different influence on the plasma kinetics of hypericin median maximal plasma levels of hypericin were detected after 360 minutes (Cmav 8.6 ng/mL) for B2, and after 150 minutes... 

Butterweck V, Lieflaender-Wulf U, Winterhoff H, Nahrstedt A. Plasma levels of hypericin in presence of procyanidin B2 and hyperoside a pharmacokinetic study in rats. Planta Med 2003 69 189-192. 

Figure 11.3.2 HPLC chromatogram of neutral polyphenolics found in Niagara grapes detected at 280 nm. Retention time 8.599 min, procyanidin B3 9.781 min, procyanidin B1 13.409 min, catechin 16.138 min, procyanidin B2 20.781 min, epicatechin 22.281 min, catechin-catechin-gallate 23.925 min, catechin-catechin-gallate isomer 28.955 min, catechin-gallate. AU, absorbance units. Reproduced from Lee and Jaworski (1987) with permission from the American Society for Enology and Viticulture.

Condensed tannins are also referred to as proanthocyanidins. They are oligomeric or polymeric flavonoids consisting of flavan-3-ol (catechin) units. Hydrolysis under harsh conditions, such as heating in acid, yields anthocyanidins. An example of a condensed tannin is procyanidin B2 (epicatechin-(4 3—>8 )-epicatechin 1.90). In this case the interflavanyl linkage is between C4 of the lower unit, and C8 of the upper unit. The linkage can also be between C4 of one unit and C6 of the second unit. 

Baba S, Osakabe N, Natsume M, Terao J. 2002. Absorption and urinary excretion of procyanidin B2 [epicatechin-(4beta-8)-epicatechin] in rats. Free Radio Biol Med 33 142-148. 

Apple C, EC, procyanidin B2 Extraction with aqueous acetone, centrifugation normal phase neutralization, SPE with C18 reversed phase removal of acetone Silica C-18 MeOH-DCM-formic acid MeOH-H20-formic acid HPLC/DAD (280 nm) 112... 

The profile (%) of polyphenolics in tamarind pericarp was dominated by proan-thcyanidins in various forms, such as (+)-catechin, procyanidin B2, (-)-epicatechin (9.4), procyanidin trimer (11.3), procyanidin tetramer (22.2), procyanidin pentamer (11.6) and procyanidin hexamer (12.8), along with taxifolin (7.4), apigenin (2.0), eriodictyol (6.9), luteolin (5.0) and naringenin (1.4) of total phenols, respectively. Tamarind seeds comprised procyanidins only, represented (%) mainly by oligomeric procyanidin tetramer (30.2), procyanidin hexamer (23.8), procyanidin trimer (18.1), procyanidin pen-tamer (17.6), with lower amounts of procyanidin B2 (5.5) and (-)-epicatechin (Sudjaroen et al., 2005). 

Mescaline (=Mezcaline 3,4,5-Trimethoxy-phenethylamine) (phenylethylamine) A-Methylmescaline (= A -Methylmezcaline 7 1Methyl-3,4,5-trimethoxy-phenethylamine) (phenylethylamine) Procyanidin B2 (= Epicatechin (4(3 —>8) epicatechin) (procyanidin dimer) Procyanidin B3 (= Catechin (4a—>8) catechin (procyanidin dimer)... 

Dallas, C., Ricardo da Silva, J.M., Laureano, O. (1996b). Products formed in model wine solutions involving anthocyanins, procyanidin B2 and acetaldehyde. J. Sci. Food Agric., 44, 2402-2407. 

Day of the year Procyanidin B1 Catechin Procyanidin B2 Epicatechin Procyanidin B2 gallate Epicatechin gallate... 

Figure 2.20 Chromatogram relative to analysis of dimer procyanidins in the skins extract (fraction ethyl acetate from C18 cartridge) (sample volume injected 10p,L). 1. procyanidin Bl, 2. procyanidin B3, 3. procyanidin B2...

Figures 2.21,2.22 and 2.23 show the chromatograms relative to analysis of catechins and procyanidins prior to fractionation in the cartridge, of catechins monomer (fraction diethyl ether) and of procyanidins dimer (fraction ethyl acetate), respectively. As evidenced by Figures 2.20 and 2.23, the main procyanidin in seeds is procyanidin B2, however in skins procyanidin Bl prevails.

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