Extraction of curcuminoids from Curcuma longa L. by fatty acid-based ionic liquid aqueous solution: Experimental and mechanism study

Abstract

Curcuminoids originated from the plant Curcuma longa L. show high medical values. Herein, ionic liquids (ILs) were synthesized using fatty acids and alcohol amines to extract curcuminoids. Through single-factor experiments and response surface methodology (RSM) optimization, the extraction amount of curcuminoids by [TEA][FA-C₇] aqueous solution reached 34.89 mg/g at a liquid-solid ratio of 16.36 mg/g and an extraction temperature of 36 °C, surpassing that of methanol. The extraction capacity of [TEA][FA-C₇] to curcuminoids was 299.33 mg/g. Furthermore, the separation of extracts and recovery of fatty acids were studied. Quantum chemical calculations and molecular dynamics simulations were performed to investigate the extraction mechanism profoundly. This study not only proposed a novel green solvent for the extraction of curcuminoids from the plant Curcuma longa L. but also provided the possibility of applying fatty acid-based ILs to extract natural medicine efficiently.

Keywords: Alcoholic amines; Curcuminoids; Extraction; Fatty acid; Ionic liquid.