Two new steroidal glycosides from the root of Cynanchum auriculatum

Abstract Two new steroidal glycosides named cyanoauriculoside A ( 1 ) and B ( 2 ), have been isolated from the roots of Cynanchum auriculatum Royle ex Wight. The structure of cyanoauriculoside A ( 1 ) was determined to be 20- O -acetyl-penupogenin-3- O - β -D-glucopyranosyl-(1→4)- β -D-glucopyranosyl-(1→4)- α -L-cymaropyranosyl-(1→4)- β -D-cymaropyranosyl-(1→4)- α -L-diginopy-ranosyl-(1→4)- β -D-cymaropyranoside. Cyanoauriculoside B (2) was characterized as 20- O -acetylpenupogenin-3- O - β -D-glucopyranosyl-(1→4)- α -L-cymaropyranosyl-(1→4)- β -D-cymaropyranosyl-(1→4)- α -L-diginopyranosyl-(1→4)- β -D-cymaropyranoside. The structures of these compounds were elucidated based on the chemical and spectroscopic evidence.