Oligomeric procyanidins

Pati, S. et al.. Simultaneous separation and identification of oligomeric procyanidins and anthocyanin-derived pigments in raw red wine by HPLC-UV-ESI-MS, J. Mass Spectrom., 41, 861, 2006. 

Some herbal products are prepared from a mixture of different plant species and plant parts. Hawthorn is standardized to contain 5% oligomeric procyanidins made from the leaves, blossoms, and fruit of Crataegus laevigata and Crataegus monogyna [6]. Studies have shown that the therapeutic efficacy of hawthorn is not solely the result of one type of component, one plant part, or a single species [6]. 

Haslam, E., In vino veritas oligomeric procyanidins and the ageing of red wines. Phytochemistry 19, 2577, 1980. 

Dallas, C., Ricardo-da-Silva, J.M., and Laureano, O., Interactions of oligomeric procyanidins in model wine solutions containing malvidin-3-glucoside and acetaldehyde. J. Sci. Food Agric. 70, 493, 1996. 

Svedstrom, U. et al., Isolation and identification of oligomeric procyanidins from Craetagus leaves and flowers, Phytochemistry, 60, 821, 2002. 

Condensed tannins (= proanthocyanidins) unlike hydrolysable tannins, condensed tannins are polymeric flavans that are not readily hydrolysable. They often consist of molecules of catechin and epicatechin joined by carbon-carbon bonds. Hence catechin and epicatechin are referred to as monomers oligomers containing 2-4 (epi)catechin units are referred to as oligomeric procyanidins (OPC). 

Garcia-Ramirez B, Fernandez-Larrea J, Salvado MJ, Ardevol A, Arola L, Blade C. 2006. Tetramethylated dimeric procyanidins are detected in rat plasma and liver early after oral administration of synthetic oligomeric procyanidins. J Agric Food Chem 54 2543-2551. 

It is a diuretic. An extract of the flowers and leaves improves cardiac output and the contractility of the heart muscle. Flavonoids in hawthorn have been shown to increase blood flow in the heart by dilating blood vessels in coronary arteries. Hawthorn has lowered cholesterol in animal studies, probably due to its oligomeric procyanidins (OPC), a type of bioflavonoid similar to that found in the extracts of grape seed and grape skin. 

Figure 16.4 Influence of ionic strength on the aggregates formation between BSA (6.1 x 10 mM) and oligomeric procyanidins from grape seed (O.lOmM) (in 12% aqueous ethanol, 0.1 M acetate buffer, pH 5.0) [78].

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). 

Romeyer, F, Macheix, J. J., Sapis, J. C. (1986). Changes and importance of oligomeric procyanidins during maturation of grape seeds. Phytochemistry, 25, 219-221. 

The Lethal Dose (LD50) of an alcoholic extract of hawthorn leaves and fruit called Crataegutt administered orally was 33.8 mL/kg in rats and 18.5 mL/kg in mice. This particular extract was manufactured by Schwabe and contained 2% or 10% oligomeric procyanidins. Death occurred after approx 30 minutes and was caused by sedation and apnea (19). 

Wu Q, Chen H, Lv Z, Li S, Hu B, Guan Y et al (2013) Oligomeric procyanidins of lotus seedpod inhibits the formation of advanced glycation end-products by scavenging reactive carbonyls. Food Chem 138 1493-1502... 

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