Steroidal saponins obtained by biotransformation of total furostanol glycosides from Dioscorea zingiberensis with Absidia coerulea.

Five new steroidal saponins (1-5) were isolated from the fermentation broth of total furostanol glycosides from tubers of Dioscorea zingiberensis C.H. Wright incubated with a fungal, Absidia coerulea AS 3.3389, along with known saponins, zingiberensis new saponin (6), deltonin (7), prosapogenin A of dioscin (8), and protobioside (9), and their structures were established by NMR spectroscopy and mass spectrometry as well as by comparison with previously reported spectral data in the literatures. The induced effects in vitro on rat platelet aggregation of all compounds were evaluated.