Abstract
The fronds extracts of Glaphyropteridopsis erubescens (WALL.) COPEL. contain besides the already known flavonol glycosides (afzelin and quercitrin) three new flavan-4-ol glycosides, eruberin A (I), B (II) and C (III), which belong to a new type of proanthocyanidin. By means of spectroscopic and chemical methods, the structures 5, 7-dihydroxy-4'-methoxy-6, 8-dimethyl-2", 4 (S)-oxido-2 (R)-flavan-5-β-D-glucopyranoside (I), 4 (S), 5, 7-trihydroxy-4'-methoxy-6, 8-dimethyl-2 (R)-flavan-5, 7-O-β-D-diglucopyranoside (II) and 5, 7-dihydroxy-4 (S), 4'-dimethoxy-6, 8-dimethyl-2 (R)-flavan-5, 7-O-β-D-diglucopyranoside (III) are proposed. Eruberin C (III) may be an artifact.
