THE PROANTHOCYANIDIN POLYMERS IN SOME SPECIES OF ONOBRYCHIS

Proanthocyanidin (PA) polymers (condensed tannins) were isolated and p urified from the leaves of 26 accessions and species of sainfoin (Onob rychis). Analysis of the degradation products by HPLC revealed that ep icatechin, gallocatechin and epigallocatechin were present as both ter minal and extension units in all the samples studied while catechin wa s a terminal unit only. Quantitative analysis showed that epigallocate chin was the dominant extension unit in all of these polymers (52-63% total units). A mean degree of polymerization (DP) of 6.5 (by HPLC) an d 9 (by Gel Permeation Chromatography) was obtained. The PA polymers c onsist principally (73-85%) of delphinidin units and 78-87% of cis-iso mer units in all the samples studied.