Related Experiment Video
Updated: May 8, 2026

Preparation of Expanded Chitin Foams and their Use in the Removal of Aqueous Copper
Published on: February 27, 2021
Preparation, characterization and antioxidant activity of phenolic acids grafted carboxymethyl chitosan
Jun Liu1, Jian-feng Lu, Juan Kan
1College of Food Science and Engineering, Yangzhou University, Yangzhou 225127, Jiangsu, China.
Abstract:
In this study, three phenolic acids including gallic acid (GA), caffeic acid (CA) and ferulic acid (FA) were grafted onto N,O-carboxymethyl chitosan (NOCC) by a free radical mediated grafting method. The grafted copolymers obtained were all water-soluble samples. UV-vis absorption peaks of the grafted copolymers shifted toward longer wavelengths. FT-IR spectroscopy of the grafted copolymers exhibited additional phenolic characteristics of the aromatic ring CC stretching within 1450-1650 cm(-1). NMR spectroscopy of the grafted copolymers showed new peaks at 6.2-7.6 ppm assigned to the phenyl protons of phenolic acids. These results all confirmed the successful grafting of three phenolic acids to NOCC. The conjugation probably occurred at amine of NOCC and carboxyl groups of phenolic acids. The grafted copolymers exhibited decreased crystallinity as compared to NOCC and chitosan. Moreover, antioxidant activity in vitro assays showed that the antioxidant property decreased in the order of GA-g-NOCC>CA-g-NOCC>FA-g-NOCC>NOCC>chitosan. Our results suggested the potential of phenolic acids grafted NOCC for the development of effective antioxidant agents.
Related Concept Videos
Preparation of Carboxylic Acids: Carboxylation of Grignard Reagents
Preparation of Carboxylic Acids: Overview
Preparation of Carboxylic Acids: Hydrolysis of Nitriles
Radical Autoxidation
Preparation of Acid Anhydrides
The carboxylate ion acts as a nucleophile that attacks the carbonyl carbon of the acid chloride to form a tetrahedral intermediate. Subsequently, the re-formation of the carbonyl group with the loss of the chloride ion as a leaving group leads to the formation of an acid...
Carboxylic Acids to Acid Chlorides

