Endophytic naphthopyrone metabolites are co-inhibitors of xanthine oxidase, SW1116 cell and some microbial growths

Fractionation of the extract of Aspergillus niger. IFB-E003, an endophyte in Cyndon dactylon, gave four known compounds naphtho-gamma-pyrones rubrofusarin B, fonsecinone A, asperpyrone B and aurasperone A, which were further investigated biologically. Rubrofusarin B was shown to be cytotoxic to the colon cancer cell line SW 1116 (IC50: 4.5 mug ml(-1)), and aurasperone A inhibitory on XO (xanthine oxidase) (IC50: 10.9 mumol 1(-1)). Moreover, the four naphtho-gamma-pyrones exhibited growth inhibitions against the five test microbes with MICs ranging in between 1.9 and 31.2 mug ml-1. The present recognition of rubrofusarin B and aurasperone A as strong co-inhibitors on XO, colon cancer cell and some microbial pathogens is of significance for the imperative discovery of new relevant therapeutic agents. (C) 2004 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved.