Chlorinated Cyclopentene Derivatives and Antifungal Activities from Periconia sp. Induced by the One Strain Many Compounds Strategy and Host Plant Culture.

Eleven new chlorinated cyclopentene derivatives, periconsins A-K, and a new diketopiperazine, periconzin, were found from Periconia sp. cultured in three different media by the one strain many compounds strategy. Additionally, the C-1 methyl hydroxylation of chlorinated cyclopentene was found for the first time in the host plant culture. The structures were identified by extensive spectroscopic analyses, electronic circular dichroism (ECD) and 13 C NMR calculations, and single-crystal X-ray diffraction. Compounds 3 , 5 , 7 - 11 , 15 , and 17 showed significant antifungal activities against the plant pathogens Periconia sp. , Altemaria sp. , and Nigrospora oryzae with MICs ≤2 μg/mL. Other compounds had antifungal activities with MICs ≤8 μg/mL. The antifungal structure-activity relationship of these metabolites indicated that the chlorine at C-5 can increase the activity, but the hydroxy group at C-1 lowered the activity.