[Timosaponins E1 and E2].

Abstract

By means of silica gel chromatography and HPLC, two compounds were isolated from Anemarrhena asphodeloides Bge.. On the basis of chemical and spectral (MS, 1H, 13CNMR, IR) analyses, their structures were elucidated as (25S)-26-O-beta-D-glucopyranosyl-22-hydroxy-5 beta-furost-3 beta, 15 alpha, 26-triol-3-O-beta-D-glucopyranosyl (1-->2)-beta-D-galactopyranoside (1), and (25S)-26-O-beta-D-glucopyranosyl-22-methoxy-5 beta-furost-3 beta, 15 alpha, 26-triol-3-O-beta-D-glucopyranosyl (1-->2)-beta-D-galactopyranoside (2). They are named as timosaponin E1 (1) and timosaponin E2 (2) respectively. The structure of anemarrhenasaponin-I (A) is briefly discussed. Timosaponins are the main active constituents of Anemarrhena asphodeloides, most of them were shown to can inhibit platelet aggregation.