Hymenopsins A and B and a macrophorin analogue from a fungicolous Hymenopsis sp.

Hymenopsin A (1), hymenopsin B (2), and a new macrophorin analogue, 2',3'-epoxy-13-hydroxy-4'-oxomacrophorin A (3), have been isolated from a fungicolous isolate of Hymenopsis sp. (MYC-1703; NRRL 37638). The structures and relative configurations of these compounds were assigned on the basis of 2D NMR and MS data, and the identity of 1 was confirmed by X-ray crystallographic analysis. The absolute configuration of 2 was proposed on the basis of CD analysis using both empirical and computational methods. Compounds 2 and 3 showed antibacterial activity against Staphylococcus aureus and Bacillus subtilis. Compound 3 was also active against Aspergillus flavus and Fusarium verticillioides.