Novel furostanol saponins from the bulbs of Allium macrostemon B. and their bioactivity on [Ca2+]i increase induced by KCl.

Chemical reinvestigation of the ethanol extract of the dried bulbs of Allium macrostemon B. led to the isolation of two novel furostanol saponins, named macrostemonoside M (1) and macrostemonoside N (2), together with six known saponins. The structures of new compounds were elucidated on the basis of extensive spectroscopic analysis including 1D and 2D NMR as (25R)-22-hydroxy-5β-furostane-1β,2β,3β,6α-tetraol-26-O-β-d -glucopyranoside and 22-hydroxy-5β-furost-25-(27)-ene-1β,2β,3β,6α-tetraol-26-O-β-d -glucopyranoside, respectively. The pharmacological activities of all the saponins on [Ca2+]i increase induced by KCl were evaluated.