Cytotoxic Saponins from the Root of Dipsacus asper Wall

Cytotoxic activitiy of seven hederagenin saponins isolated from the root of Dipsacus asper were investigated in vitro against L1210, HL-60 and SK-OV-3 tumor cell lines by the MTT method. $3-O-\alpha-L-rhamnopyranosyl-(1{\rightarrow}2)-\alpha-L -arabinopyranosyl$ hederagenin (2),\;$3-O-\beta-D­xylopyranosyl-( 1{\rightarrow}3)-\alpha-L-Rhamnopyranosyl-(1{\rightarrow}2)-\alpha-L -arabinopyranosyl$ hederagenin (6) and $3-O-\beta-D-glucopyranosyl-(1{\rightarrow}3)-\alpha-L-rhamnopyranosyl-( 1{\rightarrow}2)-\alpha-L-arabinopyranosyl$ hederagenin (7) exhibited the potent cytotoxicity against the three tumor cell lines with $IC_{50}$ values ranging from 4.7 to 8.7 ${\mu}g/mL$, with the exception of compound 7, which exhibited weak cytotoxic activity against SK-OV-3 $(IC_{50}\;22.5\;{\mu}g/mL)$. Other compounds did not exhibit any cytotoxic activity $(IC_{50}>30{\mu}g/mL)$.