An efficient two-step approach for the preparative separation and purification of eight polyphenols from Hibiscus manihot L. flower with high-speed countercurrent chromatography

In the present study, a green and efficient ultrasonic-assisted extraction method of polyphenols from Hibiscus manihot L. flowers (HMLF) was performed, and the corresponding experimental parameters were optimized by Taguchi OA Design. Meanwhile, a two-step high-speed counter-current chromatography coupled with macroporous resin was successfully estab-lished with the optimal two-phase solvent systems comprising EtOAc-MeOH-H2O (100:3:100, v/ v/v) and Hex-EtOAc-MeOH-H2O (1:5:1:5, v/v/v/v) to isolate and prepare eight polyphenols with purities exceeding 95%, including two phenolic acids and six flavonoids, respectively. The yield of the isolated polyphenols was determined to be 50.4 mg from the enriched extract in a single run. Moreover, the interactions of the eight isolated compounds with AChE and BuChE were explicitly evaluated and described by molecular docking. This study confirms that the proposed method is a cost-effective and powerful strategy for the scaled-up extraction and preparative sepa-ration of the high-purity polyphenols from HMLF, and provides an opportunity for automation and systematic preparation of natural products used in the food and pharmaceutical industries.(c) 2023 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).