A-type proanthocyanidin antioxidant from Dioclea lasiophylla

The A-type proanthocyanidin, epigallocatechin-(2 beta-->7,4 beta-->8)-epicatechin, together with the known epicatechin, luteolin 3'beta -D-glucopyranoside, chrysoeriol 7 beta -D-glucopyranoside and 2-methylpentan-2,4-diol, were isolated from leaves of Dioclea lasiophylla. The structures were established on the basis of their spectral data. Antioxidant activities of isolates were measured using the auto-oxidation of beta -carotene in a linolenic acid suspension method. (C) 2000 Elsevier Science Ltd. All rights reserved.