Unusual Nitrogenous Phenalenone Derivatives from the Marine-Derived Fungus Coniothyrium cereale

摘要

The new phenalenone metabolites 1 , 2 , 4 , and 6 were isolated from the marine-derived endophytic fungus Coniothyrium cereale , in addition to the ergostane-type sterol ( 3 ) and entatrovenetinone ( 5 ). Compounds 1 and 2 represent two unusual nitrogen-containing compounds, which are composed of a sterol portion condensed via two bonds to phenalenone derivatives. Compound 6 , which contains unprecedented imine functionality between two carbonyl groups to form a oxepane -imine-dione ring, exhibited a moderate cytotoxicity against K562, U266, and SKM1 cancer cell lines. Moreover, molecular docking studies were done on estrogen receptor α-ligand binding domain (ERα-LBD) to compounds 1 and 2 to correlate with binding energies and affinities calculated from molecular docking to the anti-proliferative activity.