Supercritical fluid extraction of Coriandrum sativum and subsequent separation of isocoumarins by high-speed counter-current chromatography

A novel supercritical fluid extraction (SFE) method has been developed for extracting essential oil from the aerial part of Coriandrum sativum. Various experimental conditions were investigated to optimise the SFE. It suggested that the extraction of 35 °C, 8 MPa, 2 h might be the optimisation to get the maximum of coriander essential oil. Then, high-speed counter-current chromatography (HSCCC) was successfully used in one step for the isolation and purification of coriandrone B, coriandrin, dihydrocoriandrin and coriandrone A from the coriander oil with a two-phase system composed of n-hexane–ethyl acetate–methanol–water (3:7:5:5, v/v/v/v) for the first time. High-performance liquid chromatography (HPLC) was employed to analyse the HSCCC fractions and revealed that the purities of the isocoumarins were all above 90%, and the chemical structures were identified by spectroscopic analysis including ESIMS, 1H NMR and UV.