STEROIDAL GLYCOSIDES FROM ALLIUM-MACLEANII AND A-SENESCENS, AND THEIRINHIBITORY ACTIVITY ON TUMOR PROMOTER-INDUCED PHOSPHOLIPID-METABOLISMOF HELA-CELLS

A new polyhydroxylated cholestane trisdesmoside and a new spirostanol pentasaccharide, together with five known spirostanol saponins, were i solated from the bulbs of Allium macleanii, and two known spirostanol saponins were isolated from the bulbs of A. senescens. The identificat ion and structural assignments of the steroidal glycosides were perfor med by spectroscopic analysis and hydrolysis. Furthermore, the isolate d compounds were evaluated for inhibitory activity on 12-O-tetradecano ylphorbol-13-acetate (TPA)-stimulated P-32-incorporation into phosphol ipids of HeLa cells, which is recognized as an excellent primary scree ning test to identify new antitumour-promoter compounds.