A new steroidal glycoside from the fruits ofSolanum myriacanthum

A new cholestane-type steroidal glycoside, solamyriaside A (1), was isolated from the fruits ofSolanum myriacanthumDunal (Solanaceae), along with two known steroidal glycosides, namely, solaviaside A (2) and aculeatiside A (3), and three known steroidal alkaloid glycosides, namely, solamargine (4), khasianine (5) and solasonine (6), which were isolated for the first time from this plant. Based on spectroscopic data as well as chemical evidence,1was determined to be 3-O-alpha-L-rhamnopyranosyl-(1 -> 2)-O-[alpha-L-rhamnopyranosyl-(1 -> 4)]-beta-D-glucopyranosyl-22R,25R-cholest-5-ene-3 beta,16 alpha,22,26-tetraol 26-O-beta-D-glucopyranoside. The cytotoxic activity of1-6against HL-60 human promyelocytic leukaemia cells was examined. Compounds4-6showed cytotoxic activity. Among them,4exhibited the strongest activity with an IC(50)value of 4.64 +/- 0.17 mu M, similar to the activity of cisplatin, a positive control.