Bioassay-guided isolation of potent α-glucosidase inhibitory compounds from the fruit of Piper mullesua Buch-Ham ex D Don. and their in silico screening.

Two bioactive compounds caffeic and sinapic acid were isolated from the fruit of the Piper mullesua Buch-Ham ex D Don using bioassay guided approach. These compounds were isolated from water fraction using column chromatography followed by semi preparative HPLC. These compounds showed very potent anti-diabetic and antioxidant activities. The molecular docking was carried out to predict the mode of interaction of the isolated compounds with α-glucosidase. The in vitro α-glucosidase inhibitory activity of caffeic and sinapic acid was determined, and their IC50 values were found 0.67 and 0.82 µg/ml, respectively. A QSAR equation was generated with an R2 value of 84.81%, which is suitable enough for predicting the IC50 values of test molecules. The aforementioned finding confirms the isolated compounds show very significant anti-diabetic potential which is supported by the molecular docking and QSAR study. So, it has ample scope for drug development with further in vivo and clinical study.