Myrothecols G and H, Two New Analogues of the Marine-Derived Quinone Sesquiterpene Penicilliumin A

Two new quinone sesquiterpenes named myrothecols G and H (1 and 2), a pair of C-1′ diastereomers of 13-hydroxyl penicilliumin A, were isolated from the mycelia solid cultures of Myrothecium sp. SC0265. Their structures, including the absolute configurations, were established on the basis of the spectroscopic data combining with the theoretical conformational analysis. The cytotoxic activities of 1 and 2 were tested against a panel of human tumor cell lines.