TIMOSAPONINS E1 AND E2

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-β-D-glucopyranosyl-22-hydroxy-5β-furost-3β,15α,26-triol-3-O-β-D-glucopyranosyl (1→2)-β-D-galactopyranoside (1), and (25S)-26-O-β-D-glucopyranosyl-22-methoxy-5β-furost-3β,15α,26-triol-3-O-β-D-glucopyranosyl (1→2)-β-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.