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

An undescribed cytochalasan talarochalasin (<b>1</b>), with four known analogues 20-deoxycytochalasin F (<b>2</b>), cytochalasin F (<b>3</b>), cytochalasin B₂ (<b>4</b>), and cytochalasin T (<b>5</b>) were obtained from the mangrove endophytic fungus <i>Talaromyces</i> 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 <b>4 and 5</b> 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 <b>1</b> showed weak cytotoxic activities against VCaP and T-24 cell lines. While these cytochalasans showed no inhibition against α-glucosidase.