**4. Conclusions**

In the present work, RPMs were synthesized using 4-VP as a functional monomer and EGMRA as a crosslinker and RCMs were further prepared by electrospinning. Their physicochemical properties and chemical structures were analyzed and characterized. It was observed that RCMs have a negative charge on the surface and have an excellent adsorption effect on dencichine in an aqueous solution and the RCMs showed excellent mechanical and thermodynamic properties. The support of the adsorption isotherm model for Langmuir-Freundlich indicated that the adsorption of dencichine and its analogues by RCMs was multilayers adsorption, and the kinetic adsorption suggested that chemisorption was the main adsorption mechanism. In the meantime, the RCMs showed excellent water solubility and were highly discriminating against dencichine and its analogues, and were conducive to the extraction and purification of a water-soluble bioactive component from natural products. This synthetic method is green, efficient, eco-friendly and cost effective. Therefore, our study provides a novel, efficient and green polymer for the concentration and the purification of dencichine and will open up a new avenue for the purification of dencichine.

**Author Contributions:** Methodology, L.L. (Long Li); formal analysis, L.L. (Long Li), X.L. and Q.H.; investigation, L.L. (Long Li), L.L. (Lanfu Li), Q.H. and S.W.; data creation, L.L. (Lanfu Li) and X.L.; writing—original draft preparation, L.L. (Long Li); writing—review and editing, L.L. (Long Li), X.L. and Q.H.; supervision, Q.H.; project administration, Q.H. and X.L. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Informed Consent Statement:** Informed consent was obtained from all subjects involved in the study.

**Acknowledgments:** The research was supported by the National Natural Science Foundation of China (31860192), the Natural Science Foundation of Guangxi (2020GXNSFBA159009), the China Postdoctoral Science Foundation (2020M683209), the Opening Project of Guangxi Key Laboratory of Clean Pulp & Papermaking and Pollution Control (2019KF28) and the Scientific Research Foundation of Guangxi Minzu University (2019KJQD10).

**Conflicts of Interest:** The authors declare no conflict of interest.
