Pigments with antimicrobial and cytotoxic activities from the coprophilous fungus isolated from horse dung.

Four previously undescribed phenazine-derived pigments (1-4), along with seventeen known compounds, were isolated from a strain cultured on solid rice medium. Structural elucidation of the new compounds was achieved through extensive spectroscopic analysis, while known compounds were identified by comparison with literature data. The antimicrobial and cytotoxic activities of the isolated compounds were assessed. Compounds 2, 5, and 11 exhibited weak antifungal activity against at 200 μM, while compounds 5, 6, 11, 12, 15, and 20 demonstrated moderate antibacterial effects against at the same concentration. Notably, compound 4 showed significant cytotoxicity against breast cancer cells (MCF-7, IC = 6.8 μM), and moderate cytotoxicity against cervical cancer cells (HeLa, IC = 25.0 μM). Moreover, the known quinone-derived pigments 10, 12, and 13 displayed potent cytotoxic activities against the three tested cancer cell lines (MCF-7, PC3, and HeLa). These results highlight the potential of these compounds as promising bioactive agents for cancer treatment.