Triterpene glycosides from Curculigo orchioides and their cytotoxic activity

Six new cycloartane glycosides (1-6) were isolated from the rhizomes of Curculigo orchioides. The structures of 1-6 were determined by spectroscopic analyses and the results of hydrolytic cleavage. Compounds 1-6, and their common aglycone (1a), were evaluated for cytotoxic activity against HL-60 human leukemia cells. Compounds 1 and 1a showed cytotoxic activity against HL-60 cells with IC(50) values of 9.0 and 1.8 microM, respectively. The Cancer cell growth inhibition of 1a was also examined using a panel of 39 human Cancer cell lines in the Japanese Foundation for Cancer Research.