VOLUME 71 : 2023

The previously known cytotoxic cytochalasan, cytochalasin B (1), was isolated and purified from the ethyl  acetate extract of the rice fermentation culture of the Alpine asphodel-associated Dothideomycetes fungus,  Sparticola triseptata after iterative chromatographic purifications. The structure of 1 was established  through extensive 1D and 2D-NMR spectroscopic experiments along with high-resolution electrospray  ionization mass spectrometry (HRESIMS) and by comparison of its spectroscopic data with the literature.  The potential of cytochalasin B (1) as antidiabetic and anti-obesity compound was screened using  microplate, colorimetric enzyme inhibitory assays. Thus, 1 displayed significant in vitro α-glucosidase  and porcine pancreatic lipase inhibitory activities with IC50 values of 5.46 µM and 8.43 µM, respectively  when compared to the positive drug controls, acarbose and Orlistat®. Molecular simulation experiments  using molecular docking showed moderately strong affinity of 1 onto the active sites of α-glucosidase  and porcine pancreatic lipase with binding energies (BE) of -8.6 kcal/mol and -7.5 kcal/mol, respectively.