Chemical constituents and hypoglycemic activities analysis of secondary metabolites of the endophytic fungus from camellia sp.
Objective To study the chemical composition of the endophytic fungus Paraconiothyrium brasiliense from camellia sp.and their hypoglycemic effects.Methods The ethyl acetate extracts were separated and purified by silica gel column chromatography,thin layer chromatography(TLC),and high performance liquid chromatography(HPLC).The structures of the obtained compounds were characterized according to spectroscopic methods or by comparison with relevant literature data.The hypoglycemic activity of the isolated compounds was screened by pNPG method,and the inhibitory mechanism of α-glucosidase was further studied by molecular docking method.Results Eleven known compounds were isolated from the ethyl acetate extract after fungal fermentation.The glucose-lowering activity assay indicated that compound 6 had an inhibitory activity on α-glucosidase with IC50 value of(15.48±11.82).Molecular docking assay showed that the binding energy of compound 6 was-6.5 kJ/mol.Conclusion Compounds 1~5,7~11 are isolated for the first time from the fungus Paraconiothyrium brasiliense.Compound 6 shows a moderate inhibitory effect on α-glucosidase.