A new cytochalasan metabolite with cytotoxic activity from the mangrove endophytic fungus Talaromyces sp. GDUT-10

An undescribed cytochalasan talarochalasin (1), with four known analogues 20-deoxycytochalasin F (2), cytochalasin F (3), cytochalasin B₂ (4), and cytochalasin T (5) were obtained from the mangrove endophytic fungus Talaromyces sp. GDUT-10. Their structures were determined through the comprehensive analysis of NMR, HR-ESIMS spectra, quantum chemical ECD calculations, and quantum chemical calculation of ¹³C NMR combined with DP4 probability analysis. The compounds were evaluated for their cytotoxic and α-glucosidase inhibitory activities. Compounds 4 and 5 showed cytotoxic activities against three cancer cell lines, including VCaP, PC-3, and T-24, with IC₅₀ values ranging from 10.35 ± 0.23 μmol/L to 38.15 ± 0.90 μmol/L. Compound 1 showed weak cytotoxic activities against VCaP and T-24 cell lines. While these cytochalasans showed no inhibition against α-glucosidase.