Microsphaerins A-D, four novel benzophenone dimers with activity against MRSA from the fungus Microsphaeropsis sp.

Bioassay-guided isolation using an MRSA whole cell assay yielded four novel benzophenone dimers, microsphaerins A-D (1-4), from two Singapore isolates of the soil anamorph Microsphaeropsis sp. The structures of 1-4 were elucidated on the basis of spectral data and the structures of 1 and 4 were confirmed by X-ray crystallographic analyses. (c) 2008 Elsevier Ltd. All rights reserved.