An α-Glucosidase and Pancreatic Lipase Inhibitory Cytochalasan Derivative from the Dothideomycetes fungus, Sparticola triseptata

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 -glucosidase and porcine pancreatic lipase inhibitory activities with IC 50 values of 5.46 M and 8.43 M, 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 -glucosidase and porcine pancreatic lipase with binding energies (BE) of -8.6 kcal/mol and -7.5 kcal/mol, respectively.