Steroidal glycosides and aromatic compounds from Smilax riparia

Abstract

Two new steroidal glycosides named riparosides A (1) and B (2), and two aromatic compounds (3, 4), together with four known flavonoid derivatives have been isolated from the EtOH extract of the rhizomes and roots of Smilax riparia A. DC. The structure of riparoside A (1) was determined to be 3-O-α-L-rhamnopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→6)] -β-D-glucopyranosyl 3β,20α-dihydroxy-5α-furost-22(23)-ene 26-O-β-D-glucopyranoside. Riparoside B (2) was characterized as 3-O-α-L-rhamnopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→6)] -β-D-glucopyranosyl 3β,16β-dihydroxy-5α-pregnan-20-one 16-O-[5-O-α-D-glucopyranosyl 5-hydroxy-4-methyl-pentanoic acid]-ester 26-O-β-D-glucopyranoside. Compounds 3 and 4 were elucidated as a sucrosyl ferulic acid ester and 7-O-methyl-10-oxythymol gentiobioside, respectively. © 2006 Pharmaceutical Society of Japan.