Chemical composition and antibacterial activity of essential oils of Thymelaea hirsuta from Algeria

Abstract

Abstract. Souhila B, Takia L, Messaoud R, Pierre C, Gilles F. 2019. Chemical composition and antibacterial activity of essential oils of Thymelaea hirsuta from Algeria. Biodiversitas 20: 2868-2876. The objectives of this study were to determine the chemical composition and to evaluate the antibacterial activity of Thymelaea hirsuta (L.) Endl., essential oils from seven sampling locations in M'sila region (Algeria). Extraction of essential oils was carried out by the hydro-distillation; the analysis of chemical composition of essential oil was carried out by GC-MS. Antimicrobial activity was performed by disc diffusion method at the essential oil concentration of non-diluted and diluted (1:2, 1:4 and 1:8 v:v of DMSO) against eight species of bacteria. The results showed that the average yields of essential oils were 0.3 ± 0.12%. A total of 45 components were identified, averaging 98.2 ± 1.85% of the total oils. The main components were nonanal-n (10.39 ± 3.21%), hexadecanoic acid (9.77 ± 2.81%), nonanoic acid (9.13 ± 6.49%), triacontane (7.2 ± 3.34%), isopropyl tetradecanoate (6.16 ± 1.99%) and tridecane (4.87 ± 3.1%). Based on the UPGMA cluster analysis, there were two clades of T. hirsuta. T. hirusta has a chemical polymorphism with different chemotypes marked in nature. There were four chemotypes identified in the essential oil of T. hirsuta in the region of M'sila. The essential oil of T. hirsuta has antibacterial activity against eight tested bacteria on the concentration-dependentt manner.

Phytochemical Screening and In Vitro Antibacterial Activity of Methanol Extract of Thymelaea hirsuta and Anacyclus pyrethrum from Algeria against Multi-Drug Resistant Bacteria Associated with Skin Infections

“…Furthermore, Jalayar et al 33 reported that the methanol extract of Anacyclus pyrethrum has an inhibitory effect on Escherichia coli at the concentrations from 300 to 1000 mg/mL with a value of MIC and MBC corresponding to 800 mg/ mL. According to previous study 19,34 , the absence of antimicrobial activity does not mean that the bioactive compounds are not present in the plant or the plant has no antimicrobial activity against microorganisms since various factors such as the dose of solvent used in the extraction of metabolites, the extraction time and rotary evaporator used during extraction of crude also trigger influence on the activities of crudes (the temperature used)…”