Tropolactones A-D, four meroterpenoids from a marine-derived fungus of the genus Aspergillus

Cytotoxic meroterpenoids, tropolactones A-D were isolated from the whole broth extract of a marine-derived fungus of the genus Aspergillus. Their structures were established through a variety of two-dimensional NMR techniques. The absolute configuration of tropolactone A was determined using the modified Mosher's method.