Identification of chaetoviridin e from a cultured microfungus, Chaetomium sp. and structural reassignment of chaetoviridins B and D

Chaetoviridins E (1) and B (2) are antibiotic active components isolated from the mycelial extract of an elicited laboratory-cultured coprophilous fungus, Chaetomium sp. obtained from the scat of an emu. The structure of chaetoviridin E was determined to be diastereomeric with the known compound chaetoviridin A, whereas a structure revision of chaetoviridins B and D (10) is proposed, reassigning them to be bicyclic lactol-lactones. The structures of chaetoviridins B and E were determined by detailed spectroscopic analysis, while the revision of chaetoviridin D is through analogy.