Secondary Metabolites And Their Bioactivities From Two Medicinal Mangrove-derived Endophytic Fungi

The growing environment of mangrove plant community is mainly located in the intertidal zone and the intertidal zone where seawater and fresh water meet in the tropical zone,sub-thermal coastal zone and intertidal zone.Due to the perennial periodic seawater erosion,mangrove plants and their endophytes have formed a special metabolic mechanism to adapt to the unique habitat,producing a large number of metabolites with novel structure and unique activity.At present,the study of secondary metabolites of endophytic fungi in mangrove has become an important way to discover lead compounds of natural medicine.In this paper,two medicinal mangrove-derived fungi T.flavus TGGP35 and Phomopsis sp.MGF222 were used as research objects.A total of 57 compounds were isolated and identified from their secondary metabolites using modern chromatography and spectral methods.Forty two compounds?1-42?were isolated from the conventional fermentation products of T.flavus TGGP35.Including,eleven isocoumarins?1-11?,three meroterpenoids?12-14?,five lactones?15-19?,four sterone?20-23?,seven benzene derivatives?24-30?,seven nitrogen compounds?31-37?,and five other types of compounds?38-42?.Compounds 1 and 2 are new compounds.Fifteen compounds?43-57?were isolated from the conventional fermentation products of Phomopsis sp.MGF222.Including,seven sterone?43-49?,and eight other types of compounds?50-57?.Compound 43 is new compound.Some compounds were texted for their antioxidant activity,antibacterial activity and?-Glucosidase inhibitory activity.Compounds 8,20,25,43,44,45,48 had obvious antioxidant activity,with IC₅₀ values of 13.44,19.51,12.42,19.75,18.52,19.21,and 17.56?M,respectively.Compound 46 showed obvious inhibitory activity against C.albicans and S.aureus,with the MIC values of 12.5 and 6.25?g/m L,respectively.Compound 47had weak inhibitory activity against S.aureus,with a MIC value of 6.25?g/m L.Compound 14 showed potent inhibitory activity against?-Glucosidase enzyme,with an IC₅₀ value of 306.4?M,which is stronger than the positive control acarbose(IC₅₀=313.9?M).In this study,a series of isocoumarins and a series of steroids were isolated from two endophytic fungi.We obtained the compounds with?-Glucosidase enzyme inhibition activity,antioxidant activity and antibacterial activity,which provided theoretical basis and material basis for the research and development of diabetes,antioxidant and antibacterial drugs,and also had important significance for the protection and functional development of medicinal mangrove resources.It provided experimental basis for later scientific research.