A novel deep eutectic solvent/switchable-hydrophilicity solvent/H2O system with enhanced CO2 switchability for integrated extraction of phenolics, flavonoids and essential oil from Flos Chrysanthemi Indici flower

Abstract

Despite the considerable attention received by switchable solvents in natural product extraction and biorefinery, their CO2 switching kinetic properties and extraction ability still present significant challenges. To tackle this issue, the present study has the following innovative endeavors: (1) Proposing a novel approach to enhance the performance of switchable-hydrophilicity solvent (SHS) by incorporating deep eutectic solvent (DES), leading to the successful design of a DES/SHS/H2O system. (2) Developing an innovative high-speed homogenization assisted extraction method using the DES/SHS/H2O system and applying it to the integrated extraction of phenolics, flavonoids, and essential oil from Flos Chrysanthemi Indici. The switching process was characterized using 1H-NMR, the extraction process was optimized employing response surface methodology, the components of extracted essential oils were analyzed by GC-MS, and the cytotoxicity and anti-inflammatory activity of essential oils were determined through MTT and ELISA. Our findings demonstrate that the incorporation of DES can significantly augment the CO2 switching kinetics of SHS, resulting in a 32.7% reduction in switching time and a remarkable decrease of 73.7% residual content within the aqueous phase. The innovative DES/SHS/H2O based extraction method exhibited substantial enhancements in phenolics, flavonoids, and essential oil extraction efficiency compared to conventional approaches, yielding extracts with superior chemical profiles and enhanced anti-inflammatory activity. Therefore, the proposed strategy of enhancing the CO2 switching kinetic properties and extraction ability of SHS by incorporating DES is feasible, providing valuable guidance for the rational design of innovative smart solvent systems. The developed DES/SHS/H2O system, exhibiting improved performance, holds significant application and research prospects.