A NOVEL MYCOTOXIN - THE CHAETOGLOBOSIN-N FROM INFESTED MAIZE BY PHOMOPSIS-LEPTOSTROMIFORMIS .2. STRUCTURE ELUCIDATION BY H-1 AND C-13 NMR

From culture on maize of the strain MRC 2654 of Phomopsis leptostromif ormis, two fungal metabolites, unusual to this fungus, have been isola ted in the methanolic extract. The acute toxicity for rats of these co mpounds justifies the present structural investigation. H-1 and C-13 N MR spectra allow to establish for these molecules some partial structu res containing an indole unit and several condensed cycles. On the bas is of these NMR results, the compound F = 185-degrees-C is identified to the term M of the chaetoglobosin series and the more polar compound , F = 205-degrees-C, named chaetoglobosin N, appears to be a new term in this series.