O-carboxymethylated chitins

Tokura, S. Tamura, H. (2001) O-carboxymethyl-chitin concentration in granulocytes during bone repair. Biomacromolecules, 2, 417-21. 

Tokura, S., Miuray, Y., Johmen, M. et al., 1994. Induction of drug specific antibody and the controlled release of drug by 6-O-carboxymethyl-chitin. Journal of Controlled Release, 28(1-3) 235-241. 

Watanabe K., SaikiL, UrakiY., TokuraS., andAzumal. 1990. 6-O-carboxymethyl-chitin (CM-chitin) as adrug carrier. Chem Pharm Bull (Tokyo) 38 506-509. 

Nishimura, S Nishi, N Tokura, S Nishimura, K Azuma, I. Bioactive chitin derivatives. Activation of mouse-peritoneal macrophages by O-(carboxymethyl) chitins. Carbohydrate Research, 1986,146, 251-258. 

Tokura, S., Baba, S., Uraki, Y., Miura, Y, Nishi,N., Hasegawa, O. Carboxymethyl-chitin as a drug carrier of sustained release. Carbohydrate Polymers. 1990, 13, 273-281. 

Numerous substituted derivatives of chitin and chitosan are known [67] some important examples are shown in Scheme 10.9. The possibility of forming either anionic (5,7,8,11) or cationic (9,12) derivatives should be noted. The O-carboxymethyl (5) and N-carboxymethyl (11) polymers are of particular interest as they have stronger complex-forming capabilities with metal ions than either unsubstituted chitosan or EDTA [65]. In practice, derivatives formed by substitution via the 2-amino group of chitosan are more common than those substituted via the 6-hydroxy position of the glucopyranose grouping [65]. 

Tokura et al.49 synthesized a polyamide of the Perlon type (40) starting from a 6-O-carboxymethyl-D-glucosamine derivative as monomer.This compound was obtained by carboxylmethylation of chitin with monochloroacetic acid, followed by hydrolysis of the glycosidic linkage. Hie molecular weight (Mw 15,000) of the resulting water-soluble polyamide 40 was determined by gel-permeation chromatography and electrophoresis (Scheme 11). 

A complete list of semi-synthetic heparinoids is outside the scope of this article. Products of sulfation of neutral polysaccharides include sulfates of starch, cellulose, - - xylan, dextran, " guaran, and synthetic polymers of o-glucose. A somewhat closer simulation of the structure of heparin was attempted by sulfating polysaccharides containing amino sugars or uronic acids or both, such as chitin and chitosan, " and the corresponding N-formyl, N-(car-boxymethyl), O-(carboxymethyl), and 5-carboxylated - deriva-... 

As already indicated, the number of polysaccharide derivatives reported is enormous, and indeed, many papers have been published on particular types, for example, O-(carboxymethyl) cellulose, and enzyme derivatives of polysaccharides. On such derivatives alone, reviews have been, or could be, written the present article must, therefore, of necessity be a condensed form restricted to the principal findings. Where reviews on particular derivatives have been published, this is indicated, and, generally, only subsequent papers are considered here. The reader may also find it useful to refer to other works that consider a number of derivatives of particular polysaccharides, such as cellulose, " chitin, starch, " and others. References to polysaccharide derivatives are now being reported annually in Specialist Periodical Reports. ... 

Chitinase assay was determined by a modified Schales procedure using colloidal and/or soluble chitin as the amount of enzyme that liberated 1 pmol of reducing sngar per minute (Imoto and Yagishita 1971). This method was nsed as the standard assay. To measnre the activity toward other substrates, powdered chitin, colloidal chitin, carboxymethyl chitin, ethylene glycol chitin, chitosan 7B, chitosan 8B, chitosan 9B, chitosan lOB, p-nitrophenyl-P-o-A-acetyl glucosaminide (pNP-Gl-cNAc), and several chitin/chitosan oligomers were used instead of solnble chitin. 

Tokura S., Hasegawa O., Nishimura S., Nishi N., and Takatori T. 1987. Induction of methamphetamine-specific antibody using biodegradable carboxymethyl-chitin. Anal Biochem 161 117-122. 

O-Carboxymethyl (CM)-chitin was prepared according to the method described previously (see Scheme 2), which is mainly based on the procedure of Trujillo [21]. The degree of substitution at the C-6 hydroxyl group was 0.60, as determined by elemental analysis, potentiometric titration, and the infrared (IR) spectrum [22]. The molecular weight, as based on viscosity, was 63,000, using the viscosity equation proposed by Kaneko et al. [25]. 

Muzzarelli R.A.A., Tanfani F., JV-(carboxymethyl) chitosans and iV-(O-catboxybenzyl) chitosans Novel chelating polyampholytes, in Chitin and Chitosan, Eds. Hirano S. and Tokura S., The Japanese Society of Chitin and Chitosan, Totori, 1982, pp. 45-53. 

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