UPLC-Q-TOF-MS/MS-Based Targeted Discovery of Chetomin Analogues from Chaetomium cochliodes .

Chetocochliodin M ( 5 ) containing a rare cage-ring and chetocochliodin N ( 6 ) featuring an unusual piperazine-2,3-dione ring system together with known analogues chetomin ( 1 ), chetoseminudin C ( 2 ), chetocochliodin I ( 3 ), and oidioperazine E ( 4 ) were targeted for purification from the fungus Chaetomium cochliodes using a UPLC-Q-TOF-MS/MS approach. The structures of the new compounds were elucidated using HR-ESI-MS, NMR, and ECD spectra. Compounds 1 , 3 , and 6 exhibited strong cytotoxic activities against A549 and HeLa cancer cell lines.