Epicoccins A–D, Epipolythiodioxopiperazines from a Cordyceps-Colonizing Isolate of Epicoccum nigrum

Epicoccins A–D (<b>1</b>–<b>4</b>), four unique epipolythiodioxopiperazines possessing unusual sulfur bridges, have been isolated from cultures of a Cordyceps-colonizing isolate of Epicoccum nigrum. The structures of these compounds were determined mainly by analysis of their NMR spectroscopic data. The relative and absolute configuration of epicoccin A (<b>1</b>) was established by single-crystal X-ray diffraction analysis. Epicoccin A (<b>1</b>) showed modest antimicrobial activity.