天名精内生真菌Alternaria arborescens 次生代谢产物及其抗肝癌作用初筛OA

Objective To investigate the secondary metabolites of the endophytic fungus Alternaria arborescens from Tianmingjing(Herba Carpesii)and their anti-hepatocellular carcinoma activities,and to provide a reference for the discovery of novel lead compounds against hepatocellular carcinoma.Methods Secondary metabolites from an active fungal strain isolated from Tianmingjing(Herba Carpesii)were separated and purified using modern isolation techniques,and the structures of the isolated compounds were elucidated by spectroscopic methods.The in vitro cytotoxic activity of the isolated compounds against HepG2 cells was evaluated by the CCK-8 assay,so as to screen for active constituents from the active strain.Results A total of 11 compounds were isolated and identified from the rice fermentation products of the active endophytic fungus Alternaria arborescens from Tianmingjing(Herba Carpesii),including three macrocyclic compounds:terpestacin(1),10,11-dehydrocurvularin(2),and curvularin(3);five polyketides:stemphyperylenol(4),altertoxin I(5),altertoxin II(6),alternariol(7),and alternariol-9-methyl ether(8);one sesquiterpene lactone:telekin(9);one steroid:ergosterol peroxide(10);and one monoterpene compound:nectriapyrone(11).Compounds 1-10 showed inhibitory effects on HepG2 cells to varying degrees,among which compounds 1,2,7,and 9 exhibited relatively strong inhibitory activity,with IC50 values of(27.09±1.75)μM,(12.13±0.68)μM,(47.60±2.04)μM,and(24.46±1.80)μM,respectively.Conclusion Eleven compounds were isolated and identified from the rice fermentation products of the endophytic fungus Alternaria arborescens from Tianmingjing(Herba Carpesii).Among them,compounds 1-9 and 11 were isolated from this strain for the first time,which supports the plant endosymbiosis theory.These findings indicate that endophytic fungi can produce bioactive molecules identical or similar to those of the host plant and have substantial research potential.