New antifungal and cytotoxic steroidal saponins from the bulbs of an elephant garlic mutant

Saponins in bulbs of a mutant of elephant garlic were investigated, and three new steroidal saponins named yayoisaponins A-C were obtained together with the known dioscin and aginoside. Their structures, including the relative stereochemistry, were elucidated by spectral data interpretation, while the absolute stereochemistry of the sugar moieties was assigned on the basis of a chiral gas chromatographic analysis of the acid hydrolysates. Yayoisaponins A-C and aginoside exhibited not only in vitro cytotoxicity against P388 cells at 2.1 micrograms/ml, but also antifungal activity against Mortierella ramanniana at 10 micrograms/disk.