Genetic Manipulation of the COP9 Signalosome Subunit PfCsnE Leads to the Discovery of Pestaloficins in Pestalotiopsis fici.

By deleting the COP9 signalosome subunit PfcsnE from Pestalotiopsis fici, seven compounds that were newly produced by the mutant could be characterized, including five new structures, pestaloficins A-E (1 and 3-6). Pestaloficin A (1) represents a new type of dimeric cyclohexanone derivative linked through an unprecedented pentacyclic spiral ring.