Hydrophilic Molecularly Imprinted Chitosan Based on Deep Eutectic Solvents for the Enrichment of Gallic Acid in Red Ginseng Tea.

Li Li,Row Row

doi:10.3390/polym11091434

Abstract

Hydrophilic molecularly imprinted chitosan (HMICS) were synthesized based on hydrophilic deep eutectic solvents (DESs) and the DESs was used as both a template and functional monomer for the enrichment of gallic acid (GA) from red ginseng tea using a solid phase microextraction (SPME) method. Using the response surface methodology (RSM) strategy, the optimal extraction amount (8.57 mg·g−1) was found to be an extraction time of 30 min, a solid to liquid ratio of 20 mg·mL−1, and five adsorption/desorption cycles. Compared to traditional methods, the produced HMICS-SPME exhibited the advantages of simplicity of operation, higher recovery and selectivity, improved analytical characteristics and reduced sample and reagent consumption, and it is expected to promote the rapid development and wide applications of molecular imprinting.

Highlights

Gallic acid (GA) is one of the major polyphenolic compounds in plants, such as green tea, vegetables and fruits [1,2]
The binding capacity of Hydrophilic molecularly imprinted chitosan (HMICS) and Non-imprinted chitosan (NICS) increased with increasing GA concentration, and the adsorption capacity of HMICS with deep eutectic solvents (DESs)-2 was much higher than NICS without DES (Figure 3a)
The additional GA bound to HMICS compared to NICS could be attributed to the binding of GA to the imprinting sites with higher specificity

Summary

Introduction

Gallic acid (GA) is one of the major polyphenolic compounds in plants, such as green tea, vegetables and fruits [1,2]. CS is an eco-friendly and cost-effective biopolymer that can be modified by various chemical reactions to improve its physicochemical properties [8]. CS can be modified mainly using its amine group, by crosslinking reactions to make it insoluble in acidic pH or by grafting new functional groups to the amine and hydroxyl groups to add new chemical properties and improve the selectivity for the targets [9]. With the addition of new functional groups on CS, it is possible to increase the number of adsorption sites [10]

Methods

Results

Conclusion