Eucalbanins A, B and C, Monomeric and Dimeric Hydrolyzable Tannins from Eucalyptus alba REINW.

Abstract

Three new hydrolyzable tannins, eucalbanins A (5), B (8) and C (11), have been isolated from the fruit extract of Eucalyptus alba REINW., and their structures were elucidated on the basis of spectral data and chemical correlation with known tannins. Quercetin-3-O-α-L-arabinopyranoside, (+)-catechin, procyanidin b-7, and nine known hydrolyzable tannins [casuarinin, casuariin, pedunculagin, tellimagrandin I (1), gemin D (2), cornusiin B (3), 2, 3-(S)-hexa-hydroxydiphenoyl-D-glucose, penta-O-galloyl-β-D-glucose and oenothein B (4)] have also been isolated.