Steroidal Saponins from Chlorophytum orchidastrum

Six new spirostane-type saponins (1-6), named orchidastrosides A-F, and chloromaloside D were isolated from an ethanol extract of the roots of Chlorophytum orchidastrum. The saponins have neotigogenin or neogitogenin as the aglycon and oligosaccharidic chains possessing seven to nine sugar units. Their structures were elucidated mainly by 2D NMR spectroscopic analyses (COSY, TOCSY, NOESY, HSQC, and HMBC) and FABMS and HRESIMS. Compounds 1-6 were tested for cytotoxicity against two human colon cancer cell lines, HCT 116 and HT-29.