Preparation,bioactivity And Property Of Different Anionic 2-hydroxypropyl Trimethy Lammonium Chitosan

Chitin,mainly derived from shrimp and crab shells,is the second largest polysaccharide resource in nature with only less reserves than cellulose.Chitosan,as one of the most important derivatives of chitin,is a macromolecule compound obtained by partial or complete deacetylation of chitin.Chitosan is a natural and renewable biological resource with good biocompatibility and biodegradability,which attracts broad attention in such areas as agriculture,medicine,daily chemicals,food,environmental protection etc.However,the insoluble ability of chitosan in water and the insufficiency of some biological activities greatly limit its further industrial development.Chemical modification is considered to be an efficient,targeted and convenient method,which can improve or even give new functions to polysaccharides to meet different needs.As a result,the chemical modification of chitosan to improve its water solubility as well as biological activity will be conducive to the more comprehensive development of this rich polysaccharide resources.The aim of this paper is to prepare chitosan derivatives with good water solubility and excellent activity.Based on ion exchange,the anions of halogenated acetic acid,hydroxy acid and carboxyl polysaccharide were introduced into2-hydroxypropyl trimethylammonium chitosan respectively.Finally,17 kinds of anionic 2-hydroxypropyl trimethylammonium chitosan were obtained.And the datailled chemical structures of these chitosan derivatives were characterized by means of FTIR,¹H NMR,¹³C NMR,as well as elemental analysis.We emphatically studied the effects of different anions on the bioactivity of 2-hydroxypropyl trimethylammonium chloride chitosan.In order to improve the antifungal activity of chitosan,halogen groups with potentialantifungalactivitywereintroducedinto2-hydroxypropyl trimethylammonium chloride chitosan.The structures of the derivatives were characterized by FTIR,NMR,and elemental analysis.Their antifungal activity against Botrytis cinerea,Fusarium oxysporum f.sp.cucumerium Owen,Fusarium oxysporum f.sp.Niveum,and Phomopsis asparagi were studied in vitro by mycelium growth rate method.The results revealed that the halogen groups significantly increased the antifungal activity of chitosan.In order to improve the antioxidant activity of chitosan,organic acids with potential antioxidant activity,including coumaric acid,ferulic acid,p-coumaric acid,salicylic acid,ascorbic acid,gallic acid,caffeic acid and p-hydroxybenzoic acid,were introduced into 2-hydroxypropyl trimethylammonium chloride chitosan to obtain a series of chitosan derivatives.Structures identification and the evaluation of antioxidant activity,including hydroxyl radicals scavenging activity,DPPH radicals scavenging activity,and superoxide radicals scavenging activity were carried out subsequently.The results showed that the antioxidant activity of chitosan was significantly enhanced by the introduction of organic acid salts.In order to improve the hygroscopic and moisturizing activity of chitosan,the hydrophilic carboxyl polysaccharides were introduced into 2-hydroxypropyl trimethylammonium chloride chitosan to obtain three different 2-hydroxypropyl trimethylammonium chloride chitosan-carboxylic polysaccharide complex salts.The hygroscopic and moisturizing activity were tested respectively.Results showed that the hygroscopic and moisturizing activity of chitosan derivatives were enhanced significantly.In this paper,the preparation of chitosan derivatives with antibacterial activity,antioxidant activity,and hygroscopic and moisturizing activity were provided.The effects of different anions on the bioactivity of 2-hydroxypropyl trimethylammonium chloride chitosan were systematically studied,which provided a new idea for the further development of chitosan in the fields of medicine and cosmetic.