Synthesis and characteristic of 1-amino-2-propanol-based ionic liquids and effective extraction of antioxidants from Mugwort

Green extraction of natural products from plants is of high importance to the pharmaceuticals and fine chemicals industry. Novel bio-renewable ionic liquids, a class of safe and powerful medium, has aroused broad attention from the field of extraction and separation. In the present study, the 1-amino-2-propanol-based ionic liquids (PA-ILs) were used to selectively extract the antioxidants from Mugwort (Artemisia argyi Lévl. et Vant.). As revealed from the results, among ten PA-ILs carrying different counter anions, the PA/mandelic acid, PA/EDTA and PA/lactic acid exhibited the best extraction efficiency to polyphenols (120.34 mg/g), flavones (128.87 mg/g) and polysaccharides (43.62 mg/g), respectively. Furthermore, the time-dependent DPPH radical scavenging shown that flavones are the major antioxidants and PA-ILs extractants were higher than those of conventional solvents. According to the reversed-phase HPLC profiles, more polar substances (e.g. glycosides) existed in ILs extract compared with alcohols solvent. The Fermi resonance in the FT-IR spectrum indicated the complex H-bonding framework in ILs, which may act as a crucial factor to assess extraction performance. Moreover, the in vitro studies reported that the cytotoxicity of PA-ILs for HaCaT and Caco-2 cell lines was less than that of pure PA. It was, therefore, demonstrated that PA-ILs are a secure medium that can help alternate organic solutions.