Essential oil from the rhizomes of the Saudi and Chinese Zingiber officinale cultivars: Comparison of chemical composition, antibacterial and molecular docking studies

Abstract

Background: Essential oils have been known to possess useful biological activities and are widely used in aromatherapy owing to their peculiar aroma. The present study compared the essential oil composition isolated from the Chinese and Saudi ginger cultivars and determined their antimicrobial activity. Methods: The volatile compounds were extracted by a hydrodistillation method and the composition was analysed by gas chromatography coupled with mass spectrometry (GC–MS). The antibacterial activity of oils was tested against the pathogenic Gram positive and Gram negative bacterial strains. Potential bioactivities were predicted with the help of Prediction of activity spectra for substances (PASS) software and the molecular docking studies on the mycobacterial protein were carried out using Pyrex with Vina wizard tool. Results: A total of 43 and 30 volatile components were identified in the Chinese and Saudi varieties respectively. α–zingiberene in the Chinese and ar-curcumene in Saudi ginger oil were found to be the major volatile constituents. Ginger oil showed better antibacterial activity against Gram positive than Gram negative bacteria. Molecular docking studies showed ar-curcumene to have high binding affinity for the inhibition of bacterial protein. Conclusion: The presence of the biological active compounds such as α–zingiberene, ar-curcumene and β-sesquiphellandrene makes ginger essential oil a potential source of antimicrobial agents and as an additive/preservative in the food industry.

Keywords

• Antibacterial activity
• Essential oil
• GC-MS
• Ginger
• Molecular docking