(662d) Amino Acid-Functionalized Ionic Liquid Mediated Liquid-Liquid Extraction Process for the Effective Production of Natural Phenolic Products

In recent years, there is a growing interest in obtaining bioactive substances from natural resources. Natural phenolic products refer to the bioactive substances those possess several phenolic hydroxyl groups in their molecular structures and they have played a great role in human health such as free radical quenching, resistance against aging and cancer prevention. Because of the unique physicochemical features of natural bioactive compounds such as high boiling point, thermal instability and relatively large molecular weight, the separation and production of natural phenolic products has been a great challenge for scientists and engineers. Traditional separation methods mainly include various chromatographic technologies, such as high performance liquid chromatography, supercritical fluid chromatography, and so on. Although these technologies could give effective separation for the natural phenolic products, they are almost only applied at a laboratory scale on account of the low capacity and the large consumption of absorbents and solvents. Therefore, novel separation methods for the effective production of natural phenolic products remain in great demand now. In the present work, selective separation of natural phenolic products from structurally related compounds has been performed by liquid-liquid extraction, using amino acid-functionalized ionic liquids (AAILs) as extractants. It was found that AAIL could bring obviously elevated separation selectivity compared to traditional solvents. Then, in order to reduce the viscosity of the extraction system and improve the distribution coefficients of phenolic solutes to a more favorable range, several molecular solvents were used as diluent and binary extraction solvents composed of AAIL with diluent were applied for the extraction. Both the kind of diluent and the concentration of IL could take effect on the extraction equilibrium, and great improved separation efficiency has been reached compared to using only AAIL as single extraction solvent. At last, to give an insight to the AAIL mediated extraction processes, more related work such as the binary or ternary liquid-liquid phase equilibrium of AAIL-involved systems and the Kamlet-Taft solvatochromic studies were also performed. In a word, through the present work, the promising prospect of AAIL-mediated liquid-liquid extraction process for the effective production of natural phenolic products has been revealed.