Epicoccolides: Antimicrobial and Antifungal Polyketides from an Endophytic Fungus Epicoccum sp Associated with Theobroma cacao

In the search for new compounds to protect plants from fungi, an endophytic fungus, Epicoccum sp. CAFTBO, obtained from Theobroma cacao was found to produce three polyoxygenated polyketides, namely epicolactone (1) and epicoccolides A (2) and B (3), together with seven known metabolites. The structures of these compounds were elucidated by a combination of detailed spectroscopic and spectrometric analyses as well as DFT calculations of the electronic circular dichroism spectra and the single-crystal X-ray diffraction analysis of 1. Compounds 1-3 showed potent antimicrobial activities and significant inhibitory effects on the mycelial growth of two peronosporomycete phytopathogens, Pythium ultimum and Aphanomyces cochlioides, and the basidiomycetous fungus Rhizoctonia solani.