Pseudodestruxins A and B: New cyclic depsipeptides from the coprophilous fungus Nigrosabulum globosum

Pseudodestruxins A (1) and B (2), two new cyclic peptides, have been isolat ed from cultures of the coprophilous fungus Nigrosabulum globosum. The stru cture of pseudodestruxin A (1) was elucidated using 2D NMR techniques and c onfirmed by single-crystal X-ray diffraction analysis. The structure of 2 w as assigned by comparing its NMR and FABMS data with those of compound 1. T he known compounds ascochlorin and 6-chlorocollectorin B were also isolated from N, globosum. Although 1 and 2 display antibacterial effects, ascochlo rin was found to be responsible for the antifungal activity of the crude ex tract.