Chitin and chitosan: Properties and applications

Chitin is the most abundant natural amino polysaccharide and is estimated to be produced annually almost as much as cellulose. It has become of great interest not only as an underutilized resource, but also as a new functional material of high potential in various fields, and recent progress in chitin chemistry is quite noteworthy. The purpose of this review is to take a closer look at chitin and chitosan applications. Based on current research and existing products, some new and futuristic approaches in this fascinating area are thoroughly discussed.

A review of chitin and chitosan applications

Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S. A. S. Nagar,Mohali, Punjab-160 062, India, Institute of Biochemistry, Faculty of Medicine, Polytechnic University, Via Ranieri 67, IT-60100 Ancona, Italy,Green Biotechnology Research Group, The Special Division for Human Life Technology, National Institute of Advanced Industrial Science andTechnology, 1-8-31 Midorigaoka, Ikeda, Osaka-563-8577, Japan, and Department of Medicinal Chemistry & Natural Products,The Hebrew University of Jerusalem, School of Pharmacy-Faculty of Medicine, Jerusalem 91120, IsraelReceived March 2, 2004

Chitosan chemistry and pharmaceutical perspectives.

http://www.mtdna.or.kr/neowiz/board/up_files/files_17/Chitin_Chitosan_polymers_chemistrySolubilityFiberFormation.pdf

Chitin and chitosan polymers: Chemistry, solubility and fiber formation

Advances in cellulose ester performance and application

Modified taxols. 5. Reaction of taxol with electrophilic reagents and preparation of a rearranged taxol derivative with tubulin assembly activity

Cellulose esters with linear aliphatic acyl substituents ranging in size from C12 (lauric acid) to C20 (eicosanoic acid) were prepared in homogeneous solution (DMAc/LiCl) using a novel synthetic method based on the use of a mixed p-toluenesulfonic/carboxylic acid anhydride. The resulting waxy cellulose esters had a high degree of substitution (DS), between 2.8 and 2.9, and showed little degradation. Thermal analysis of these cellulose derivatives by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) revealed a series of transitions that represented motion by both ester substituents and cellulosic main chain. Broad crystallization and melting transitions attributed to side-chain crystallinity were observed in the range between −19 and +55°C; these side-chain Tm and Tc transition temperatures increased by 10°C per carbon atom of the ester substituent. The Tg of these derivatives increased linearly with increasing substituent size from 94°C for C12 (cellulose laurate) to 134°C for C20 (cellulose eicosanoate). Evidence of “main-chain” crystallization was not observed for these samples, except in the case of peracetylated C12 and C14 esters, which had Tm values of 96°C and 107°C, respectively. © 1996 John Wiley & Sons, Inc.

Novel cellulose derivatives. IV. Preparation and thermal analysis of waxy esters of cellulose

In this review we will briefly summarize our earlier published studies of taxol analogues, and then present some new and as-yet-unpublished work on the preparation of some novel derivatives of taxol and baccatin III

The Chemistry of Taxol, a Clinically Useful Anticancer Agent

Cellulose derivatives with low DS. I. A novel acylation system

The water-soluble solids comprised of the ionic complex between chitosan and acetic acid, chitosonium acetate, are converted into chitin by heating. The thermally-induced conversion of a water-soluble chitosonium acetate in film form into a water-insoluble chitin film was examined by thermal analysis (DMTA, TGA, DSC, and TMA) and by solid state 13C-NMR spectroscopy. Results indicate that tan δ-transitions occur at increasingly high temperatures, and over progressively wider temperature ranges, as the transformation progresses. Likewise, the storage modulus, log E′, increases as the chitosonium acetate film undergoes “cure” and converts to chitin. Cure kinetic parameters are obtained using the model proposed by Provder et al. modified for glass transition temperature (Tg). The results suggest the existence of two sequential first order reactions, an initial and a late cure reaction, having activation energies of approximately 15 and 21 kcal/mol, respectively. © 1996 John Wiley & Sons, Inc.

Gamini Samaranayake

Papers

Modified taxols. 5. Reaction of taxol with electrophilic reagents and preparation of a rearranged taxol derivative with tubulin assembly activity

Novel cellulose derivatives. IV. Preparation and thermal analysis of waxy esters of cellulose

The Chemistry of Taxol, a Clinically Useful Anticancer Agent

Cellulose derivatives with low DS. I. A novel acylation system

Chitin derivatives. I. Kinetics of the heat-induced conversion of chitosan to chitin