Chemical constituents of essential oil of endemic <i>Rhanterium suaveolens</i> Desf. growing in Algerian Sahara with antibiofilm, antioxidant and anticholinesterase activities

<p>Twenty compounds were detected in the essential oil of <i>Rhanterium suaveolens</i> representing 98.01% of the total oil content. Perillaldehyde (45.79%), caryophyllene oxide (24.82%) and <i>β</i>-cadinol (5.61%) were identified as the main constituents. In β-carotene–linoleic acid assay, both the oil and the methanol extract exhibited good lipid peroxidation inhibition activity, with IC₅₀ values of 17.97 ± 5.40 and 11.55 ± 3.39 μg/mL, respectively. In DPPH and CUPRAC assays, however, the methanol extract exhibited a good antioxidant activity. The highest antibiofilm activity has been found 50.30% against <i>Staphylococcus epidermidis</i> (MU 30) at 20 μg/mL for essential oil and 58.34% against <i>Micrococcus luteus</i> (NRRL B-4375) at 25 mg/mL concentration for methanol extract. The <i>in vitro</i> anticholinesterase activity of methanol extract showed a moderate acetylcholinesterase inhibitory (IC₅₀ = 168.76 ± 0.62 μg/mL) and good butyrylcholinesterase inhibitory (IC₅₀ = 54.79 ± 1.89 μg/mL) activities. The essential oil was inactive against both enzymes.