Isolation of Chromanone and Isobenzofuran Derivatives from a Fungicolous Isolate of Epicoccum purpurascens

摘要

Mycoparasitic and fungicolous fungi are those which attack and colonize other fungal species, and often cause damage to the host fungi. In many cases, at least part of this damage appears to be caused by antifungal metabolites. In spite of such observations, these commonly occurring fungi remain relatively unexplored from a chemical standpoint. As a part of our ongoing studies of mycoparasitic and fiingicolous fungi as sources of new antifungal metabolites, a fungicolous isolate of Epicoccum purpurascens (MYC 1097 = NRRL 37031) was selected for investigation. Epicoccum purpurascens Ehrenb. Ex Schlecht (syn. E. nigrum Link) has been recorded as a colonist of decaying basidiocarps of larger fungi4 and has been studied as an antagonist that produces antibiotics and/or parasitizes the mycelium of fungal pathogens of crop plants. Studies of an organic extract from cultures of E. purpurascens MYC 1097 afforded two new metabolites: 7-mefhoxy-4-oxo-chroman-5-carboxylic acid methyl ester (1) and l,3-dihydro-5-methoxy-7-methylisobenzofuran (2). The known compounds 4,5,6-trihydroxy-7-methyl-3H-isobenzofuran-l-one (3) and 1,3-dihydro-4,6-dihydroxy-7-methylisobenzofuran (4) were also obtained. Details of these studies are presented here.