Chae-type cytochalasans from coculture of Aspergillus flavipes and Chaetomium globosum.

Cocultivation of the high cytochalasan-producing fungi Aspergillus flavipes and Chaetomium globosum resulted in the isolation of 11 undescribed Chae-type cytochalasans. Their structures were determined by spectroscopic data and NMR data calculations. Asperchaetoglobin A (1) was the first Chae-type cytochalasan possessing an unprecedented nitrogen bridge between C-17 and C-20 to generate a surprising 5/6/12/5 multiple ring system; asperchaetoglobins B and C (2 and 3) displayed higher oxidation with an additional epoxide at the thirteen-member ring; asperchaetoglobin D (4) was the second Chae-type cytochalasin featuring a 5/6/12 tricyclic ring system. The cytotoxic activities against five human cancer cell lines and antibacterial activities against Staphylococcus aureus and Colon bacillus of selected compounds were evaluated in vitro.