P. Sasikumar, B. Prabha, T. R. Reshmitha , Sheeba Veluthoor, A. K. Pradeep, K. R. Rohit, B. P. Dhanya, V. V. Sivan, M. M. Jithin, N. Anil Kumar, I. G. Shibi,* P. Nisha* and K. V. Radhakrishnan*
The remarkable alpha-glucosidase inhibition exhibited by the acetone extract of rhizome of Ampelocissus indica (L.) and stem bark of Vateria indica Linn. (IC50 23.2 and 1.47 µg/mL) encouraged us to isolate the phytochemicals from these plants. (+) and (-)- Hopeaphenol (1) and (2) were isolated from A. indica (L.) and V. indica Linn. respectively. The compounds 1 and 2 displayed IC50 values of 21.21 ± 0.987 and 9.47 ± 0.967 µM in a alpha-glucosidase inhibitory assay. The effect of glucose uptake performed by 2-NBDG in L6 rat skeletal muscle cells using flow cytometry (BD FACS Aria II, USA) showed potent glucose uptake by (+) and (-)- hopeaphenol with 31 % and 26.4 % respectively. The data from cell viability assay by MTT revealed that the compounds are not toxic to the cells up to 200 µM. Molecular docking studies show that the compouds bind effectively into the active site of the proteins 1BVN, 3A4A and 3AJ7. Which supported the observed alpha-glucosidase inhibition. The structures of these compounds were determined by the analysis of various spectroscopic data including HRMS-ESI, 2D NMR, CD spectra, optical activity and was unequivocally established by single crystal X-ray crystallography. Herein we are reporting the phytochemicals from Ampelocissus indica (L.) and their antidiabetic activities for the first time.
RSC Adv. 2016, 6, 77075-77082.