Efficient preparation of caffeoylquinic acids from the flowers of Artemisia anomala by supramolecular solvent/equilibrium solution extraction followed by re-extraction

In this study, the potential of supramolecular solvent/equilibrium solution (SUPRAS/EqS) for the extraction of caffeoylquinic acids from the flowers of Artemisia anomala (AAF) coupled with re-extraction was evaluated. Extraction and re-extraction parameters were optimized based on the yield of 3-chlorogenic acid, isochlorogenic acid A-C. The DPPH radical scavenging and xanthine oxidase inhibitory activity of the final extracts were also evaluated. SUPRAS/EqS, made up by n -octanoic acid, ethanol, 5% acetic acid aqueous solution, offered advantages in terms of rapidity (extraction for 1 min) and simplicity (the process involved vortex-shaken and centrifugation at room temperature), thus avoiding cost processes based on high pressure or temperature. Multi-stage countercurrent extraction (MSCE) procedure was successfully applied to reduce the consumption of extraction solvent (24-fold volume of raw materials in total). SUPRAS/EqS-MSCE extracts were evaporated to recycle ethanol and then re-extracted by water for 3 times (with a total consumption of 9-fold volume of material weight). The contents of 3-chlorogenic acid, isochlorogenic acid B, isochlorogenic acid A, isochlorogenic acid C in the final extract were 3.61 ± 0.01, 2.32 ± 0.01, 26.42 ± 0.05, 5.38 ± 0.01 mg/g dry weight of AAF with a recovery rate of 95.0%, 92.7%, 90.6% and 94.5%, respectively. Furthermore, the final extract of AAF exhibited moderate DPPH radical scavenging activity (IC 50 value was 839. 46 ± 1.02 μg/mL, vitamin C’s was 220.29 ± 1.02 μg/mL) and weak xanthine oxidase inhibitory activity (IC 50 value was 4518.56 ± 1.03 μg/mL, quercetin’s was 103.04 ± 1.04 μg/mL).