Talaroindiones A−C, New Polyketides Characterized From the Cold‐Seep‐Derived <i>Talaromyces indigoticus</i> CS‐469

Three novel polyketides, talaroindiones A-C (1-3), along with two known diphenyl ether derivatives (4 and 5) were isolated from the rice culture medium extract of the marine-derived fungus Talaromyces indigoticus CS-469. The structures of 1-3 were determined by comprehensive spectroscopic analysis and confirmed by single-crystal x-ray diffraction. Their absolute configurations were assigned using TDDFT-ECD calculations, while those of 4 and 5 were established by comparison of their experimental optical rotations with literature values. All compounds were evaluated for their antibacterial activity. Compound 4 exhibited broad-spectrum inhibitory activities against six bacterial strains, showing particularly potent activity against Vibrio harveyi and Vibrio parahaemolyticus with MIC values of 2 µg/mL.