α-Glucosidase Activity Of Oleanolic Acid And Its Oxidative Metabolites: DFT and docking studies

• Published in: Mini-Reviews in Medicinal Chemistry
• Main Author: Anouar E.H.; Zakaria N.S.S.; Alsalme A.; Shah S.A.A.
• Format: Article
• Language: English
• Published: Bentham Science Publishers 2015
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84945947662&doi=10.2174%2f1389557515666150724154044&partnerID=40&md5=b35aecc81e2f62d4e9554ac99a6b1aa9

A natural pentacyclic triterpenoid, oleanolic acid 1 and its biotransformed metabolites 2 and 3 are potential α-glucosidase inhibitors. To elucidate the inhibitory mechanism of compounds 1-3 against α-glucosidase, (i) their electronic and optical properties were calculated using DFT and TD-DFT methods at the B3LYP/6-31G(d) level of theory in gas and IEF-PCM solvent; and (ii) their binding energies to α-glucosidase were determined via a docking study. DFT results showed that the α-glucosidase inhibtion is mainly dependent on the polarity parameters of the studied compounds. Docking results revealed that the activity is increased with binding energies (i.e. the stability of ligand-receptor complex). The NMR spectroscopic data revealed that 13C and 1H chemical shifts of 1 and its hydroxylated metabolites 2 and 3 are well predicted with R2of 99% and 90%, respectively. The UV/vis spectra of substrate 1 and its transformed products 2 and 3 are well reproduced. The detailed assignments of 1H and 13C chemical shifts, and bathochromic shift of λMAXabsorption bands have been presented. © 2015 Bentham Science Publishers.