title: Naphtho-gamma-pyrone production by Aspergillus niger isolated from stored cottonseed.
abstract: Aspergillus niger was found to be the predominant fungal contaminant of stored cottonseed. Seven strains were isolated and grown on rice. The hexane-insoluble material from methylene chloride extracts of 2-week-old cultures contained components toxic to mice. Based on high-pressure thin-layer and liquid chromatographic analyses, the major components in the mixture were eight different naphtho-gamma-pyrones. Of these, the hydrated dimeric naphthopyrones aurasperones B and C occurred in higher yield than aurasperones A, iso-A, and D and the monomeric naphthopyrones flavasperone and rubrofusarin, all of which were present in the mixture. In addition, fonsecin monomethyl ether was isolated. This metabolite may be a precursor in the biosynthesis of the hydrated aurasperones; it has not been identified previously as a metabolite of A. niger. The relative amounts of the different naphthopyrones were dependent on both the growth substrate and the fungal isolate.
mesh_terms: D001234:Aspergillus niger / Q000302:isolation & purification / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D003369:Cottonseed Oil; D008401:Gas Chromatography-Mass Spectrometry; D009284:Naphthols / Q000032:analysis / Q000096:biosynthesis* / Q000302:isolation & purification; D011714:Pyrans / Q000096:biosynthesis*; D011753:Pyrones / Q000032:analysis / Q000096:biosynthesis* / Q000302:isolation & purification
chemical_list: D003369:Cottonseed Oil; D009284:Naphthols; D011714:Pyrans; D011753:Pyrones; C042551:fonsecin monomethyl ether