Novel furostanol saponins from the bulbs of Allium macrostemon B. and their bioactivity on [Ca 2+ ] 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 (25 R )-22-hydroxy-5 beta-furostane-1 beta,2 beta,3 beta,6 alpha-tetraol-26- O -beta-d-glucopyranoside and 22-hydroxy-5 beta-furost-25-(27)-ene-1 beta,2 beta,3 beta,6 alpha-tetraol-26- O -beta-d-glucopyranoside, respectively. The pharmacological activities of all the saponins on [Ca2+](i) increase induced by KCl were evaluated.