Three New Polyketides from the Insect-Associated Fungus Letendraea sp. 5XNZ4-2.

Chemical investigation of the EtOAc extract of an insect-associated fungus Letendraea sp. 5XNZ4-2 cultured in Potato Dextrose Broth (1/2 PDB) medium lead to the isolation of three new polyketides, named letendronol D (1), phomopsiketones H-I (2-3). The structures of new compounds were elucidated by the analysis of HRESIMS and NMR spectroscopic data, and the absolute configurations were determined by modified Mosher's method, ECD calculation and single-crystal X-ray diffraction. Cytotoxicity and antibacterial activities of 1 were assayed and regrettably 1 didn't display any cytotoxicity and antibacterial activity. 3 was the first phomopsiketone derivative obtaining the lactone. [ABSTRACT FROM AUTHOR]