Antifungal metabolites from Phomopsis sp. By254, an endophytic fungus in Gossypium hirsutum

Chemical and bioassay-guided fractionation of the chloroform-methanol (1:1) extract of Phomopsis sp. By254, an endophytic fungus residing in the root of Gossypium hirsutum, yielded three compounds. The structures of these compounds were elucidated by a combination of spectroscopic analysis (MS, 1Dand 2D-NMR) to be epoxycytochalasin H (1), cytochalasin N (2), and cytochalasin H (3). All the compounds were subjected to antimicrobial action against plant pathogenic fungi and plant pathogenic bacteria. As a result, compounds 1 to 3 significantly inhibited the growth of Sclerotinia sclerotiorum, Bipolaris maydis, Fusarium oxysporum, Botrytis cinerea, Bipolaris sorokiniana, Gaeumannomyces graminis var. tritici and Rhizoctonia cerealis, with IC50 value ranging from 0.1 to 50 g/ml. However, no inhibition of them was observed against plant pathogenic bacteria.