Trichodermaloids A–C,Cadinane Sesquiterpenes from a Marine Sponge Symbiotic Trichoderma sp. SM16 Fungus

Three new cadinane sesquiterpenes, trichodermaloids A ( 1 ), B ( 2 ), and C ( 5 ) were isolated from a symbiotic fungus Trichoderma sp. SM16 derived from the marine sponge Dysidea sp., together with three known ones, aspergilloid G ( 3 ), rhinomilisin E ( 4 ), and rhinomilisin G ( 6 ). The complete structures of three new compounds were determined by HR‐MS and NMR spectroscopic analyses coupled with ECD calculations. The absolute configurations of two known compounds ( 4 and 6 ) were determined for the first time. The six isolates were inactive as antibacterial agents. However, trichodermaloids A and B have shown cytotoxicity on human NCIH‐460 lung, NCIC‐H929 myeloma, and SW620 colorectal cancer cell lines with IC₅₀ values at the range of 6.8–12.7 μm .