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The essential oil of Thymus vulgaris(TVEO) has been used in traditional medicine for centuries. However, its low solubility and high volatility have limited its usage. In this study, TVEO was extracted, and its chemical composition was identified. The TVEO was extracted using a Clevenger-type apparatus and identified using Gas Chromatography/Mass Spectrometry (GC/MS). An inclusion complex was then formulated with β-cyclodextrin (βCD) to enhance its solubility, and the antibacterial activity was tested against 14 multidrug-resistant bacteria. When treated with the complex, the inactivation kinetics of Salmonellatyphimurium were evaluated under simulated intestinal conditions. Thymol and carvacrol were identified as the significant components of TVEO, comprising 47.53% and 19.27% of the oil, respectively. The solubility diagram of enclosed Thymol exhibited a Bs-type profile, with an association constant (Ks) of 202.35 M−1and a complexation efficiency of 55.07% for the formulated complex TVEO-βCD. The antibacterial activity demonstrated significant inhibition against all tested strains except for three. The study demonstrates the effectiveness of the TVEO-β-CD complex against S.typhimurium in intestinal conditions, a novel application. Unlike prior research, our work focuses on this complex's efficacy, specifically against Salmonella, showing prolonged inhibitory effects. This reveals the enhanced antibacterial activity of β-CD in solubilising TVEO, offering potential as an antimicrobial agent.

AbstractEssential Oils (EOs) from aromatic plants were reported to have an insecticidal activity against several insects and could be an alternative to synthetic insecticides. The aim of this study is to determine the chemical composition of two plants (Schinus molleand Cupressus sempervirens)grown in Algeria and to investigate their insecticidal activity against the sawtoothed grain beetle Oryzaephilus surinamensis, a secondary pest that may alter seriously the proprieties of some food products. EOs were extracted by hydrodistillation using Clevenger apparatus and analyzed by Gas Chromatography/Mass Spectrometry (GC/MS). The analysis determined that the major components of S. molleEO are β-Eudesmol (15.19 %), Elemol (13.97 %), D-Limonene (9.89 %), Spathulenol (9.33 %) and β-Phellandrene (7.72 %) while those of C. sempervirensEO are Cedrol (44.81 %), α-Pinene (15.71 %) and neoiso-Dihydrocarveol acetate (9.7 %). The biological activity of EOs was evaluated by fumigation and repellency at different concentrations and exposure times. Fumigation toxicity bioassays showed maximum efficacy was reached at a concentration of 100 μL/L of air for the two kinds of EOs (90-100 %). Repellency tests revealed that S. molleEO was moderately repellent (55.62 %), while C. sempervirensEO was highly repellent (66.25 %). In fact, the EO of the experimental plants can be incorporated into insecticidal formulations and might be efficient as alternative to synthetic insecticides for O.surinamensiscontrol. However, other tests need to be performed on other life stages of the insect.