Hippobutenolides A and B, two new long-chain fatty acid esters from the marine sponge Hippospongia lachne

[Display omitted] Two new fatty acid esters, hippobutenolides A (1) and B (2), featuring a long linear aliphatic chain attached to a butanolide residue, together with two known related ones (3 and 4), were isolated from the marine sponge Hippospongia lachne. The structures of all compounds were determined by extensive spectroscopic analysis and modified Mosher’s method. All isolates were evaluated for cytotoxicity against three non-small cell lung cancer (NSCLC) cells (A549, PC9, and HCC827) as well as one cisplatin-resistant NSCLC cell (A549-DDP) and two gefitinib-resistant NSCLC cells (PC9-GR and HCC827-GR). Compound 3 displayed cytotoxicity against all cell lines with IC50 values ranging from 18.86 to 33.24 μM.