GAS CHROMATOGRAPHY-MASS SPECTROMETRY ANALYSIS, IN VITRO ACTIVITIES, AND IN SILICO MOLECULAR DOCKING OF MAJOR COMPONENTS OF MICHELIA ALBA DC ESSENTIAL OIL AND SCENTED EXTRACTS

Abstract

Objective: The essential oil and scented extracts of Michelia alba DC. were analyzed by gas chromatography–mass spectrometry (GC–MS) and investigated for antidiabetic activities in vitro and in silico.

Methods: The identification of steam distilled essential oil and scented extracts of M. alba was performed by GC–MS on the Agilent 7890A chromatograph couple with GC-7000 Mass Triple Quadrupole. The extractions have been evaluated the antidiabetic activities by alpha-amylase (α-amylase) assay using starch as substrates. In addition, computational molecular docking analysis of significant components was studied to understanding how selected compounds interacted with α-amylase using AutoDock 4.2.

Results: The yields of M. alba of steam distilled essential oil and solvent extractions including hexane, diethyl ether, and dichloromethane were 0.16%, 0.02%, 0.47%, and 0.92%, respectively. GC–MS analysis of essential oil revealed that the main component was monoterpenoids β-linalool (65.03%). Meanwhile, 2-methylbutanoic acid was a primary in hexane extract (36.54%) and dichloromethane extract (33.07%). In the case of ether extract, the primary compound was β-linalool (37.32%) same as in essential oil. The antidiabetic activities evaluation demonstrates that essential oil and scented extracts have shown promising α-amylase inhibition activity. Essential oil from steam distillation revealed the best inhibition potential with a half maximal inhibitory concentration value of 0.67±4.7 mg/ml and their significant components demonstrated negative binding energies, indicating a high affinity to the α-amylase-binding site using molecular docking simulation.

Conclusion: Data from this study suggest that essential oil and scented extracts of M. alba DC possess in vitro α-amylase activities and can be used for therapy of diabetes.