Chemical composition of the essential oils from Tamarix dioica and determination of its antibacterial activity

Abstract

In this study, investigations of hydro-distilled essential oils of Tamarix dioica flowers and leaves performed by gas chromatography-mass spectrometry (GC-MS) revealed 31 volatile constituents. Nearly 24 (comprising 77.15% of the total volatiles) and 14 compounds (encompassing 63.15% of the total volatiles) were identified in flowers and leaves, respectively. Major constituents in flower were 1-hexadecene (6.93%), hexahydrofarnesyl acetone (5.64%), octadecane (5.60%), dodecanoic acid (5.22%), E-15-heptadecenal (4.98%), docosane (4.76%), 2-methoxy-4-vinylphenol (4.44%), 1-tetradecene (4.29%), tetracosane (4.00%), 1-docosene (3.89%), hexadecane (3.76%), nonanal (3.69%), nonanoic acid (1.33%), dihydroactindiolide (3.33%), and cyclotetracosane (3.04%), whereas the major constituents in leaves were 2-methoxy-4-vinylphenol (17.70%), dihydroactindiolide (10.27%), megastigmatrienone (5.53%), 1-hexadecene (5.10%), β-lonone (4.28%), safranal (3.35%), vitispirane (3.35%), trans-geranylacetone (2.72%), and hexahydrofarnesyl acetone (2.03%). These essential oils were screened in vitro against gram negative (G−ve) bacteria Escherichia coli (E. coli) and gram positive (G+ve) bacteria Staphylococcus aureus (S. aureus) by using disc diffusion method to determine minimum inhibitory concentration (MIC). However, it is noteworthy that essential oils from Tamarix dioica flower and leaves showed a higher activity against E. coli (MIC at 10 μg/mL) compared to S. aureus (MIC at 100 μg/mL).