Chemical Composition, Antioxidant and Antimicrobial Activities of Moroccan Equisetum ramosissimum Essential Oil and Butanolic Extract.

For the first time, the chemical profile and biological activities of Moroccan Equisetum ramosissimum essential oil (EO) were investigated, alongside comparative antioxidant and antimicrobial evaluation of a previously characterized butanolic extract (BE) and molecular docking of selected constituents. Hydrodistillation yielded 0.067% (v/w, dry weight) EO, characterized by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detection (GC-FID) and dominated by oxygenated monoterpenes and sesquiterpenes, with (+)-pulegone, γ-eudesmol, cyperotundone, viridiflorol, and carvone as major constituents. Antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), reducing power, and β-carotene bleaching assays. The EO exhibited an effective concentration producing an absorbance of 0.5 (EC50) of 50.0 µg/mL in the reducing power assay, whereas the BE showed lower IC50 (50% inhibitory concentration) values than the EO in the DPPH and β-carotene bleaching assays. Antimicrobial testing against 15 microbial strains revealed minimum inhibitory concentration (MIC) values of 0.19-12.5 mg/mL, with the lowest values against Candida albicans and Candida glabrata. Molecular docking provided complementary insights into potential interactions of selected major compounds with microbial targets. Overall, these in vitro and in silico findings support further investigation of Moroccan E. ramosissimum through toxicological and in vivo studies.