title: Polymeric proanthocyanidins from the bark of Hamamelis virginiana.
abstract: Polymeric proanthocyanidins were isolated from the bark of Hamamelis virginiana L. in yields of about 5 %. Fractionation yielded fractions with similar structures but different molecular weights with DP between 17-29 (thiolysis) and 11-20 (GPC). Polymers were composed predominantly of epicatechin and epigallocatechin as chain extension units at ratio of about 1.3:1. Terminal chain units were catechin (approximately 95 %) and gallocatechin (approximately 5 %). All chain extension units were completely galloylated at position O-3, while chain terminating units were not galloylated. Predominant interflavan linkages were 4 --> 8-bonds.
authors.forename: A
authors.initials: A
authors.lastname: Dauer
authors.forename: H
authors.initials: H
authors.lastname: Rimpler
authors.forename: A
authors.initials: A
authors.lastname: Hensel
mesh_terms: D000872:Anthocyanins / Q000737:chemistry / Q000302:isolation & purification*; D001704:Biopolymers / Q000737:chemistry; D029501:Hamamelis / Q000737:chemistry*; D024301:Plant Bark / Q000737:chemistry*; D044945:Proanthocyanidins
chemical_list: D000872:Anthocyanins; D001704:Biopolymers; D044945:Proanthocyanidins; C013221:proanthocyanidin