Polyketide Derivatives from Mangrove Derived Endophytic Fungus Pseudopestalotiopsis theae

Chemical investigation of secondary metabolites from the endophytic fungus led to the isolation of eighteen new polyketide derivatives, pestalotheols I-Q ( - ) and cytosporins O-W ( - ), together with eight known analogs ( - and - ). The structures of the new compounds were elucidated by HRMS and 1D and 2D NMR data, as well as by comparison with literature data. Modified Mosher's method was applied to determine the absolute configuration of some compounds. Compound showed significant cytotoxicity against the mouse lymphoma cell line L5178Y with an IC value of 3.0 μM. Furthermore, compounds and showed moderate antibacterial activity against drug-resistant (ATCC BAA-1605) in combination with sublethal colistin concentrations.