Isolation and structural elucidation of novel cholestane glycosides and spirostane saponins from Polygonatum odoratum

Much attention has been paid to cholestane-type steroidal glycosides because of their importance from the perspectives of both chemical diversity and significant biological activities. A phytochemical investigation of the rhizomes of Polygonatum odoratum (Liliaceae) resulted in the isolation of three novel cholestane-type steroidal glycosides (1-3) with unique Δ(14,16)-unsaturated D-ring structures as well as two novel spirostane-type steroidal saponins (4 and 5) and three known steroidal glycosides (6-8). Their structures were determined by various spectroscopic methods and chemical reactions. Steroidal saponin 7 showed significant antifungal activity against Candida albicans JCM1542 (MIC 3.1 μg/mL) and Aspergillus fumigatus JCM1738 (MIC 6.3 μg/mL).