Minutosides A and B, antifungal sulfated steroid xylosides from the patagonian starfish Anasterias minuta

Abstract

Two new sulfated polyhydroxylated steroidal xylosides, minutosides A (1) and B (2), together with the known pycnopodioside B (3), have been isolated from the brine shrimp active fraction of the ethanolic extract of the starfish Anasterias minuta. The structures have been elucidated by extensive 1D and 2D NMR as well as FABMS analysis and chemical methods. Compound 2 is the first example of a polyhydroxylated steroidal xyloside containing an amide function in the aglycon side chain. The three xylosides exhibited antifungal activity against Cladosporium cucumerinum and Aspergillus flavus.