Spatial variation in constituents of essential oils from fruit pericarp of Zanthoxylum armatum DC of Nepali origin and their antibacterial activity

Abstract

The fruit pericarp of Zanthoxylum armatum DC is used in spices and to manage different diseases like toothaches, inflamed gums, arthritis, swollen joints, insect bites, diarrhea, common flu, and respiratory difficulties by local people. In this study, the essential oil was extracted from the fruit pericarp of Z. armatum DC collected from different commercial sites in Nepal using the hydro-distillation method. The chiral gas chromatography-mass spectrometry (GC/MS) was used to identify the chemical compounds present in the essential oil with their stereochemistry. Major constituents identified in all samples included linalool, limonene, and methyl trans-cinnamate. Linalool, a monoterpene alcohol, exhibited the highest percentages in all three samples, recording 58.31%, 58.45%, and 80.37% in Salyan, Surkhet, and Myagdi respectively. Notably, twenty-five enantiomeric components were identified using chiral GC/MS among its sixty constituents. The enantiomeric component distribution of linalool and limonene was in their (+) dextrorotatory form, while others were dominant in the levorotatory form. This research underscores that Z. armatum from the Myagdi district of Nepal, is a prominent source of the medicinally and industrially important compound linalool, along with exhibiting higher antimicrobial activity. To the best of our knowledge, this represents the first report of a chiral GC/MS study conducted on this plant.

Keywords:

• Antimicrobial activity
• Chiral GC/MS
• Essential oil
• Linalool
• Zanthoxylum armatum DC