Abstract
Three new compounds were isolated from the dried bulbs of Allium macrostemon Bunge. Their structures were elucidated from their spectral data as (25R)-26-O-beta-D-glucopyranosyl-5alpha-furostane-3beta,12beta,22,26-tetraol-3-O-beta-D-glucopyranos-yl (1-->2) [beta-D-glucopyranosyl (1-->3)]-beta-D-glucopyranosyl (1-->4)-beta-D-galactopyranoside (1), (25R)-26-O-beta-D-glucopyranosyl-5alpha-furostane-3beta,12alpha,22,26-tetraol-3-O-beta-D-glucopyranosyl (1-->2) [beta-D-glucopyranosyl (1-->3)]-beta-D-glucopyranosyl (1-->4)-beta-D-galacto- pyranoside (2) and (25R)-26-O-beta-D-glucopyranosyl-5beta-furostane-3beta,12alpha,22,26-tetraol-3-O-beta-D-glucopyranosyl (1-->2)-beta-D-galactopyranoside (3), respectively. The inhibition effect of all compounds on CD40 ligand (CD40L) expression on the membrane of activated platelets stimulated by ADP was tested. Compounds 1 and 2 exhibited significant inhibitory activities in a dose dependent manner (P < 0.05), suggesting their potential application as CD40L inhibitors.