New polyoxypregnane ester derivatives from Leptadenia hastata.

Following the characterization of polyoxypregnane esters and esterified glycosides from the less polar extracts of Leptadenia hastata, 34 new congeners have been isolated from the more polar extracts. They possess sarcostin or deacetylmetaplexigenin as the aglycons and acetyl, benzoyl, cinnamoyl, nicotinoyl, and m-hydroxybenzoyl residues as the ester moieties linked at C-12 and/or C-20 of the aglycons. The oligosaccharide moiety linked to C-3 of the aglycons was made up of three to five 2,6-dideoxy-3-O-methylpyranoses, 6-deoxy-3-O-methylpyranoses, or glucose. Their structures have been elucidated on the basis of spectral evidence. Glycosides with more complex oligosaccharidic chains were tested for their antitumor activity on Raji cells.