An efficient method for extraction, separation and purification of eugenol from Eugenia caryophyllata by supercritical fluid extraction and high-speed counter-current chromatography

Supercritical fluid extraction (SFE) of eugenol from Eugenia caryophyllata was performed. The optimization of parameters was carried out using an analytical-scale supercritical fluid extraction system. Then the extraction was scaled up by 60× using a preparative SFE system under the optimized conditions of 50 °C, 30 MPa and a sample particle size of 40–60 mesh. The yield of the preparative SFE was 17.1% and the yield of eugenol was 94 mg/g of dry buds. Eugenol in the extract was separated and purified by high-speed counter-current chromatography (HSCCC) with a two-phase solvent system composed of n-hexane–ethyl acetate–methanol–water (1:0.5:1:0.5, v/v). From 1.5 g of crude extract, 804 mg of eugenol was obtained at 98.5% purity as determined by HPLC.