Cytotoxic Steroidal Saponins from Polygonatum punctatum

Four new steroidal saponins, polypunctosides A–D ( 1 – 4 , resp.), were isolated from the rhizomes of Polygonatum punctatum , together with five known steroidal saponins. On the basis of chemical and spectral evidence, the structures of the new saponins were established as (3 β ,23 S ,25 R )‐23‐( α ‐ L ‐arabinopyranosyloxy)spirost‐5‐en‐3‐yl 4‐ O ‐(6‐deoxy‐ α ‐ L ‐mannopyranosyl)‐ D ‐glucopyranoside ( 1 ), (3 β ,23 S ,25 R )‐23‐[(2‐ O ‐acetyl‐ α ‐ L ‐arabinopyranosyl)oxy]spirost‐5‐en‐3‐yl 4‐ O ‐(6‐deoxy‐ α ‐ L ‐mannopyranosyl)‐ D ‐glucopyranoside ( 2 ), (3 β ,23 S ,25 R )‐23‐[(3‐ O ‐acetyl‐ α ‐ L ‐arabinopyranosyl)oxy]spirost‐5‐en‐3‐yl 4‐ O ‐(6‐deoxy‐ α ‐ L ‐mannopyranosyl)‐ D ‐glucopyranoside ( 3 ), and (3 β ,23 S ,25 R )‐23‐[(4‐ O ‐acetyl‐ α ‐ L ‐arabinopyranosyl)oxy]spirost‐5‐en‐3‐yl 4‐ O ‐(6‐deoxy‐ α ‐ L ‐mannopyranosyl)‐ D ‐glucopyranoside ( 4 ). The cytotoxic activity of the isolated saponins was evaluated towards HeLa cells.