Cercophorins A-C: Novel antifungal and cytotoxic metabolites from the coprophilous fungus Cercophora areolata

Abstract

Cercophorins A-C (3-5), three novel isocoumarin derivatives with antifungal and cytotoxic activities, have been isolated from the coprophilous fungus Cercophora areolata (JS 166 = UAMH 7495), a colonist of porcupine dung. Two additional new isocoumarins, decarboxycitrinone (1) and 4-acetyl- 8-hydroxy-6-methoxy-5-methylisocoumarin (2), and a known tricothecene mycotoxin, roridin E (6), were also obtained from this species. Compounds 1- 6 were isolated from ethyl acetate extracts of mycelia and liquid cultures of C. areolata through bioassay-guided fractionation and are the first metabolites to be reported from a member of the genus Cercophora. Their structures were assigned on the basis of MS, selective INEPT, and 2D-NMR experiments.