The anthraquinone derivatives from the fungus Alternaria sp. XZSBG-1 from the saline lake in Bange, Tibet, China.

Four new anthraquinone derivatives 1-4 were obtained along with seven known compounds 5-11 from the extracts of the fungal strain Alternaria sp. XZSBG-1 which was isolated from the sediments of the carbonate saline lake in Bange, Tibet, China. Their structures were determined by spectroscopic methods, mainly by 2D NMR spectra. Compound 1 is a novel tetrahydroanthraquinone with an epoxy ether bond between C-4a and C-9a. In the primary bioassays, compound 3 (alterporriol T) exhibited inhibition of a-glucosidase with a IC50 value 7.2 μM, and compound 9 showed good inhibitory activity against the HCT-116 and HeLa cell lines, with IC50 values of 3.03 and 8.09 μM, respectively.