Research on the Microwave-Assisted Supercritical CO₂ Extraction of Alkaloids from <i>Gynura segetum (Lour.) Merr.</i>

Abstract

In this study, the alkaloids from Gynura Segetum (Lour.) Merr. were extracted based on the microwave-assisted supercritical CO2 extraction technique. Before extraction, the powder of Gynura Segetum (Lour.) Merr. was firstly soaked with ethanol-water solvent and irradiated by microwave The experimental conditions including ethanol concentration, soaking time and microwave irradiation time were carefully studied, and the best efficiency could be obtained when the ethanol concentration, soaking time and microwave irradiation time were respectively 90%, 10 h and 2 min. Meanwhile, a parallel experiment with only supercritical CO2 extraction was also carried out as a comparison. The results indicated the efficiency of microwave-assisted supercritical CO2 extraction method was better for extracting the alkaloids from Gynura Segetum (Lour.) Merr. samples. Finally, the structures of the crystals extracted from the Gynura Segetum (Lour.) Merr. were analyzed by infrared spectroscopy, and the seneciphylline was found as the main component of the crystals.