Biscurcudiols, myrmekioperoxides, and myrmekiodermaral from the Thai marine sponge Myrmekioderma sp.

The chemical investigation of the Thai marine sponge Myrmekioderma sp. yielded three aromatic bisabolane dimers, (R)- and (S)-4,6″-biscurcudiols (1 and 2) and myrmekiodermaral (5), and two bisabolane sesquiterpenes, myrmekioperoxides A (3) and B (4), along with seven known bisabolane sesquiterpenes (6–12). All compounds were identified by extensive study of their spectral data, including HRAPCIMS or HRESIMS, 1D and 2D NMR data, as well as by comparison of their spectroscopic data with those reported in the literatures. The absolute configuration of compounds 1 and 2 were established on the basis of experimental and calculated ECD spectra and compared the 1H NMR data with those of dicurcuphenols B and C. Ten of the isolated compounds were evaluated for cytotoxicity against a panel of cancer cell lines, including HuCCA-1, A549, HeLa, HepG2, MDA-MB-231, and MOLT-3.