Massarigenin C is a fungal metabolite that has been found inM. flavoroseaand has enzyme inhibitory activities.1,2Massarigenin C inhibits neuraminidasein vitro(IC50= 4.15 μM).2It is also an inhibitor of yeast α-glucosidase (IC50= 1.25 mM).1It reduces the postprandial peak in blood glucose levels in an oral sucrose tolerance test in normo- and hyperglycemic mice when administered at doses of 3.2, 10, and 31.6 mg/kg.