Curvicollide D, a new modified γ-lactone from the culture broth of Albifimbria verrucaria and its antifungal activity against plant pathogenic fungi.

In our screening program for new antifungal active compounds, a new modified γ-lactone curvicollide D (1) together with five known trichothecenes (2-6) were isolated from the culture filtrate of fungus Albifimbria verrucaria based on the in vitro antifungal assay. The chemical structure of new compound 1 was elucidated by NMR and HR-MS spectroscopic analyses, and the relative configurations of 1 were deduced from NOE experiments and coupling constant analysis. Compound 1 exhibited moderate antifungal activities against plant pathogenic fungi Botrytis cinerea, Colletotrichum coccodes, and Magnaporthe oryzae with MIC value in a range of 100-200 µg ml. Moreover, trichothecene compounds (2-6) displayed a broad spectrum of antifungal activities with MIC values in a range of 6.3-100 µg ml.