摘要Five new heterodimers,chalasoergodimers A-E(1-5),and three known heterodimers(6-8),along with four chae-toglobosin monomers(9-12),were isolated from a marine-derived Chaetomium sp.fungus.The structures of new compounds 1-5 were elucidated by HRESIMS,NMR,chemical calculated 13C NMR and ECD methods.Among them,compound 1 was derived from C-2'substitution of chaetoglobosin Fex(9)with ergosta-4,6,8(14),22-tetraen-3β-ol,representing a new dimerization mode among chaetoglobosin-ergosterol derivative hybrids.Compound 2 fea-tured substitution at NH-1'and constituted the first example of this dimeric type bearing an R-configuration at C-3".Compounds 3-5 were formed via a Diels-Alder cycloaddition between chaetoglobosins and 14-dehydroergosterol.Furthermore,it was revealed that compound 9-12 exhibited the significant cytotoxic activity against the human non-small cell lung cancer cell(A549),with compound 12 showing the most potent effect at an IC50 of 5.14 μM.