Cytotoxic polyketides from the desert soil-derived fungus Preussia fleischhakii H231

Three new heterodimeric polyketides, fleisine A-C (1-3), were obtained from the fermentation product of the desert soil-derived fungus Preussia fleischhakii H231. The structures of 1-3 were elucidated through an integrated analysis of spectroscopic data, while the absolute configurations were established by chemical hydrolysis followed by calculated electronic circular dichroism (ECD). Biological evaluation revealed that compounds 1 and 2 exhibited potent cytotoxicity against multiple human tumor cell lines. The IC₅₀ values ranged between 2.3 and 25.2 μM. Further in vitro assays demonstrated that compounds 1 and 2 significantly suppressed the proliferation and migration of gastric adenocarcinoma cells (SGC-7901 and MGC-803) dose-dependently. These findings demonstrate the potential of 1 and 2 as favorable candidates for further anticancer drug development.