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 –1 . Moreover, trichothecene compounds ( 2 – 6 ) displayed a broad spectrum of antifungal activities with MIC values in a range of 6.3–100 µg ml –1 .