Studies on the Steroidal Components of Domestic Plants. XLVII. Constituents of the Stem of Smilax sieboldi MIQ. (1). The Structure of Laxogenin

Abstract

From the aerial parts of Smilax sieboldi MIQ. a new steroidal sapogenin, laxogenin (I), was isolated together with tigogenin and neotigogenin. The analytical values of I corresponded to formula C₂₇H₄₂O₄ for sapogenin and C₂₉H₄₄O₅ for the acetate. On Huang-Minlon reduction I afforded tigogenin (II), and on sodium borohydride reduction of I, β-chlorogenin (III) and chlorogenin (IV) were obtained in ratio about 85 : 15. The chromic acid oxidation of I afforded a diketone (V), m.p. 229∼231°, which was proved to be identical with 25_D-allospirostane-3, 6-dione. From these results the structure of laxogenin was assumed to be 3β-hydroxy-25_D, 5α-spirostan-6-one and this assumption was confirmed by the synthesis of this compound from 5, 6-epoxydiosgenin (XI).