Exploring Teucrium Aureo-Candidum Essential Oil as a Promising Alternative to Triclosan for Targeting Enoyl-Acyl Carrier Protein Reductase: Chemical Composition, Antibacterial Activity, and Molecular Docking Study

Abstract

The chemical composition of the essential oil isolated from the aerial parts of Teucrium aureo-candidum, an endemic aromatic shrub collected from Moghrar and Djeniene Bourezg in the Nâama region (Algeria), was determined for the first time using GC/FID and GC/MS. A total of 45 constituents were identified, representing 87.73 % of the oil. Characterized by unique chemical variability, it was primarily composed of sesquiterpene hydrocarbons (29.53 %) and oxygenated sesquiterpenes (30.06 %), with the major compounds being γ-cadinene (5.24 %), δ-cadinene (4.24 %), α-muurolene (4.04 %), τ-muurolol (11.35 %), and α-cadinol (3.30 %). However, monoterpene hydrocarbons and oxygenated monoterpenes accounted for 23.98 % and 1.64 %, respectively, contributing to a relatively low fraction. The essential oil demonstrated notable antibacterial activity, particularly against Gram-positive bacteria. Due to safety concerns associated with triclosan, a known inhibitor of the Enoyl-Acyl Carrier Protein Reductase (FabI) enzyme, the essential oil components from this plant were explored as alternatives through a combination of experimental approaches and in silico molecular docking studies. The results revealed that α-cadinol, spathulenol, caryophyllene, and α-muurolene exhibited strong FabI inhibition, with better bioavailability and lower toxicity than triclosan, highlighting their potential in combating antibiotic-resistant bacteria.

Keywords: Antimicrobial activity; Essential oil; GC/MS; Molecular docking; Teucrium aureo-candidum; Triclosan.