Isolation and characterization of a fungal vacuolation factor (bikaverin).

A factor producing morphological changes, normally indicative of senescence, in fungal cultures was isolated from aged cultures of Fusarium oxysporum, and later from cultures of Fusarium oxysporum f. sp. lycopersici. It is a red crystalline substance C20H14O8 and has been shown by direct comparison to be identical with ‘bikaverin’ from Fusarium moniliforme(=Gibberella fujikuroi) and from another Fusarium species. The structure, 7,10-dihydro-6,11-dihydroxy-3,8-dimethoxy-1-methyl-12H-benzo[b]xanthene-7,10,12-trione, has been proved elsewhere by X-ray crystallography. The substance may be identical with a pigment named lycopersin and reported under a different formula.