The berkeleyacetals, three meroterpenes from a deep water acid mine waste Penicillium

Berkeley Pit Lake is a 1500 ft deep abandoned open-pit copper mine filled with over 1140 billion liters of acidic, metal-sulfate-contaminated water. This harsh environment is proving to be a source of unusual microorganisms that produce novel bioactive compounds. We recently reported the structures of berkeleydione (1) and berkeleytrione (2), two novel hybrid polyketide-terpenoid metabolites isolated from a deep water Penicillium sp. growing in Berkeley Pit Lake. In this paper we report the structures of three new compounds, berkeleyacetals A-C (3-5) isolated from extracts of this fungus. The structures of these compounds were deduced by comparison of mass spectral and NMR data to that of berkeleydione (1).