Studies on the Constituents of Asclepiadaceae Plants. LVI. Isolation of New Antitumor-Active Glycosides from Dregea volubilis (L.) BENTH.

Abstract

Seven new glycosides were isolated from the stem of Dregea volubilis (L.) BENTH. The structures of dregeosides A_p1 (1), A_o1 (2), A_a1 (3), A₁₁ (4), C₁₁ (5), K_a1 (6), and K_a1 (7) were deduced on the basis of chemical and spectral evidence as drevogenin A 3-O-3-O-methyl-6-deoxy-β-D-allopyranosyl-(1→4)-β-D-oleandropyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-β-D-cymaropyranoside, drevogenin A 3-O-β-D-glucopyranosyl-(1→4)-3-O-methyl-6-deoxy-β-D-allopyranosyl-(1→4)-β-D-oleandropyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-β-D-cymaropyranoside, drevogenin A 3-O-3-O-methyl-6-deoxy-β-D-allopyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-β-D-cymaropyranoside, drevogenin A 3-O-β-D-glucopyranosyl-(1→4)-3-O-methyl-6-deoxy-β-D-allopyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-β-D-cymaropyranoside, drevogenin C 3-O-β-D-glucopyranosyl-(1→4)-3-O-methyl-6-deoxy-β-D-allopyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-β-D-cymaropyranoside, drebyssogenin K₂ 3-O-3-O-methyl-6-deoxy-β-D-allopyranosyl-(1→4)-β-D-oleandropyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-β-D-cymaropyranoside, and drebyssogenin K₂ 3-O-3-O-methyl-6-deoxy-β-D-allopyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-β-D-cymaropyranoside, respectively. Among them, 1 and 2 were active against Ehrlich carcinoma (solid type), and the latter was also active against melanoma B-16.