This study represents the first investigation of the chemical composition and the antioxidant and antimicrobial activities of Ononis aurasiaca Förther & Podlech, a plant species endemic to the Aures Mountains of Algeria. The essential oil of the plant aerial parts was analysed using GC-MS. The in vitro antioxidant activity was evaluated using three methods. A total of 44 compounds were identified. The major constituents were dodecanal, hexahydrofarnesylacetone, 2-tridecanone, phytol, 1-heneicosene, and n-heneicosane. The oil displayed significant activity in the β-carotene bleaching assay, moderate scavenging activity against DPPH radicals and a low ability to reduce iron ions. Antibacterial tests conducted on four strains revealed effectiveness primarily against Gram-positive strains, specifically Staphylococcus aureus ATCC 25923 and ATCC 43300, while showing limited impact on Gram-negative strains, Pseudomonas aeruginosa ATCC 27853 and Escherichia coli ATCC 25922. Antifungal activity tests involving two moulds revealed a stronger inhibition against Scedosporium apiospermum compared to Aspergillus niger.
Keywords: Ononis aurasiaca; antimicrobial activity; chemical composition; essential oil; scavenging activity.