Isolation of (-)-cryptosporiospin, a chlorinated cyclopentenone fungitoxic metabolite from Phialophora asteris f. sp. helianthi.

The (-)-enantiomer of cryptosporiopsin, a chlorinated cyclopentenone fungitoxic metabolite, was isolated from Phialophora asteris f. sp. helianthi. Next to a comparable fungitoxic activity was shown by crypstosporiopsin, the product particularly inhibits growth of Sclerotinia sclerotiorum, an important pathogen on sunflower. Two further metabolites were tentatively identified as a stereoisomer of cryptosporiopsin and its dehydrated derivative.