Cytochalasans from the fungus Chaetomium globosum with cytotoxic activities against HepG2 cell line

Abstract

Five previously undescribed cytochalasans, chaetomichalasins A–E, along with seventeen known analogues, have been isolated from the solid culture of the fungus Chaetomium globosum. Their structures were elucidated by extensive spectroscopic analysis, with absolute configurations confirmed by electronic circular dichroism calculations. All compounds were assessed for their cytotoxicity against HepG2 cell line, with nine exhibiting cytotoxic activity with IC₅₀ values ranging from 2.36 to 36.23 μM. Preliminary structure-activity relationship analysis suggested that the double bond between C-6 and C-7 should play a key role in the cytotoxicity of these active compounds. Further pharmacological studies revealed that chaetomichalasin C induced G2/M cell cycle arrest and apoptosis in HepG2 cells dose dependently.