Menverins A-D, new highly oxygenated guaiane lactones from Hainan gorgonian Menella verrucosa (BRUNDIN)

Four new highly oxygenated guaiane lactones, menverins A±D (1 ± 4), were isolated from the gorgonian Menella verrucosa (BRUNDIN) from the South China Sea. Their structures and relative configurations were elucidated on the basis of spectroscopic data. All compounds contain a conjugated alpha-methyl-substituted alpha, beta- unsaturated gamma-lactone moiety, a C(8)=C(9) conjugated with the gamma-lactone moiety, and an exocyclic methylene group at C(4) (trivial numbering).