Steroidal saponins from Hosta longipes and their inhibitory activity on tumour promoter-induced phospholipid metabolism of HeLa cells

Article abstract of DOI:10.1016/0031-9422(96)00030-1

Three new spirostanol saponins and two new furostanol saponins were isolated from the underground parts of Hosta longipes. Their structures were determined to be (25R)-5α-spirostane-2α,3β-diol (gitogenin) 3-O-{O-α-L- rhamnopyranosyl-(1 → 2)-β-D-galactopyranoside}, gitogenin 3-O-{O-α-L- rhamnopyranosyl-(1 → 2)-O-[β-D-glucopyranosyl-(1 → 4)]-β-D- galactopyranoside}, (25R)-5α-spirostan-3β-ol (tigogenin) 3-O-{O-α-L- rhamnopyranosyl-(1 → 2)-O-[β-D-glucopyranosyl-(1 → 4)]-β-D- galactopyranoside}, 26-O-β-D-glucopyranosyl-22-O-methyl-(25R)-5α- furostane-2α,3β,22ξ,26-tetrol 3-O-{O-α-L-rhamnopyranosyl-(1 → 2)-β-D- galactopyranoside} and 26-O-β-D-glucopyranosyl-22-O-methyl-(25R)-5α- furostane-2α,3β,22ε,26-tetrol 3-O-{O-α-L-rhamnopyranosyl-(1 → 2)-O- [β-D-glucopyranosyl-(1 → 4)]-β-D-galactopyranoside}, respectively. The isolated saponins and their derivatives were examined for inhibitory activity on 12-O-tetradecanoylphorbor-13-acetate-stimulated ³²P-incorporation into phospholipids of HeLa cells as the primary screening test to find new antitumour-promoter compounds.