The Secondary Metabolites And Their Bioactivities From Two Fungi Derived From Xylocarpus Granatum

Xylocarpus granatum is a tree or shrub of Xylocarpus family,one of the main species of mangrove.It is distributed in the coastal areas of India,Vietnam,China and Malaysia,and only grows in Hainan Province in China.As a folk medicine,X.granatum mainly used in the treatment of dysentery,cholera,fever and insect repellent.Scholars have systematically studied the chemical constituents of X.granatum,but there are few reports on the endophytic fungi of X.granatum.In order to develop and utilize the endangered resources of X.granatum,we hope to isolate some new structures and acitive compounds from the fungi of X.granatum.In this study,two endophytic fungi Penicillium sp.MGP11 and Eupenicillium sp.HJ002,isolated from the roots and stems of X.granatum,were used as the research objects.By using the methods of natural product separation and spectral identification,43 compounds were isolated and identified from these two fungi,of which 6 were new compounds.37 compounds?1?37?were isolated from MGP11,including 11isocoumarins?1-11?,8 austin meroterpenes?12-19?,6 lactones?20-25?,3 steroids?26-28?,4 benzene derivatives?29-32?,2 alkaloids?33-34?and 3 other compounds?35-37?.6 compounds?38?43?were isolated from HJ002,including 3 benzene derivatives?38-40?and 3 other compounds?41-43?.Compounds 1-4,22 and 38 are new compounds,the planar structures and relative configurations were determined by1D/2D NMR and NMR calculation,the absolute configurations of new compounds were determined by CD spectrum comparison and Mosher's esterification method.Some compounds isolated from two mangrove-derived endophytic fungi were evaluated for their antibacterial,growth inhibition of H.armigera Hubner larvae,antioxidant and?-Glucosidase inhibitory activities.The results showed that compounds 6(IC₅₀=4.56?M)and 32(IC₅₀=8.13?M)had better total antioxidant activity than positive control trolox(IC₅₀=12.96?M),the IC₅₀0 values of?-Glucosidase inhibitory activity of austin terpenoids 13-14,17-19 were 249.9,224.5,252.3,270.4 and 289.7?M,respectively,which were higher than positive control acarbose(IC₅₀=313.9?M).In conclusion,several novel secondary metabolites were isolated from two endophytic fungi of X.granatum.The planar structures and relative configurations were determined by 1D/2D NMR and NMR calculation,and the absolute configurations were determined by CD spectrum comparison and Mosher's esterification.7 compounds with significant biological activities were screened out,which showed the development and utilization value of endophytic fungi of X.granatum.