Pseudoceranoids A-J, Sesquiterpene-Based Meroterpenoids with Cytotoxicity from the Sponge .

Pseudoceranoid A (), a rare merosesquiterpene featuring a rearranged 4,9-friedodrimane-type core with a crotonolactone moiety, two new rearranged 4,9-friedodrimane-type sesquiterpene cyclopentanones ( and ), and three new rearranged 4,9-friedodrimane-type sesquiterpene hydroquinones (-), along with two new drimane-type sesquiterpene derivatives ( and ), as well as two new 4,9-friedodrimane-type sesquiterpene quinones ( and ), were isolated from the South China Sea sponge . The structures of compounds were established by analysis of spectroscopic data, as well as by single-crystal X-ray diffraction, DP4+ probability analyses, and calculated electronic circular dichroism. Compound showed weak cytotoxicity against K562, H69AR, and MDAMB-231 cell lines with IC values of 3.01, 7.74, and 9.82 μM, respectively. Compound exhibited cytotoxicity against the H69AR cell line with an IC value of 2.85 μM.