6-Amino-6-deoxy-celluloses

Cellulose is converted to chlorine deoxy cellulose whieh is reacted with an amino acid to form a carboxy-subslituted amino deoxy cellulose. Show the reactions involved. 

The replacement of the tosyloxy groups in cellulose tosylate and its derivatives upon interaction with amines leads to the formation of mixed polysaccharides containing units of N-alkyl(aryl)-substituted amino-deoxy sugars. 

In a study on the alkaline stability of cellulose, Clayton and Jones188 chromatographed the trimethylsilyl ether of 1-amino-1-deoxy-D-glu-citol, and the retention time of a synthetic aminodisaccharide alditol has been given.487... 

Amethopterin (Methotrexate, 4-amino-4-deoxy-Ar -methyIpteroyl-L-glutamic acid) [59-05-2] M 454.4, m 185-204°(dec), [a]p°+19° (c 2, 0.1N aq NaOH). Commonest impurities are 10-methyl pteroylglutamic acid, 4-amino-10-methylpteroylglutamic acid, aminopterin and pteroylglutamic acid. Purified by chromatography on Dowex-1 acetate, followed by filtration through a mixture of cellulose and... 

Fordyce, Charles R., Cellulose Esters of Organic Acids, I, 309-327 Foster, A. B., Zone Electrophoresis of Carbohydrates, XII, 81-115 Foster, A. B., and Huggard, A. J., The Chemistry of Heparin, X, 335-368 Foster, A. B., and Stacey, M., The Chemistry of the 2-Amino Sugars (2-Amino-2-deoxy-sugars), VII, 247-288... 

Another interesting organic material usually used to immobilize enzymes is chitosan [95, 96]. Chitosan is a poly((1 4)-2-amino-2-deoxy-P-D-glucose) (Fig. 9.5), which is a product of deacetylation of chitin, the second polysaccharide ranked by its prevalence in nature, just after cellulose. 

Glucopyranose, 4-acetamido-1,2,3,6-tetra-O-acetyI-4-deoxy-D-, 187 —, 5-amino-5-deoxy-D-, 116,132,133 —, 4-amino-4,6-dideoxy-/3-D-, 153 —, 1,4-anhydro-a-D-, from cellulose on heating, 441,442 —, 1,6-anhydro-jS-D-effect of flame retardants on pyrolysis of, 471... 

Amination can be achieved by reductive amination of carboxyl groups using sodium cyano-borohydride [124]. By this method, 2-amino-2-deoxy functionalized amylose and cellulose have been produced. Reductive amination can also be applied to the synthesis of other amino derivatives of various oxidized polysaccharides such us xanthan [125] or alginic acid and galactomannans [126]. 

Chitosan, a polymer of j8-(I 4)-linked 2-amino-2-deoxy-D-glucose residues, is formed on deacetylation of chitin. As pointed out already, this polysaccharide takes an extended conformation similar to that of cellulose. Deacetylation of chitin is very easily evaluated in view of the NMR spectra, as illustrated in Fig. 24.5. The three polymorphs of chitosan, ten-don-chitosan (from crab shell), L-2 (from shrimp shell), An-nealed (from crab shell chitosan annealed at 22°C in the presence of water) are easily distinguished, consistent with the data for the polymorphs as obtained by a powder X-ray diffraction data [38, 39]. The observed non-equivalence of two chitosan chains, as viewed from the splittings of the C-1 and C-... 

Chitosan is a cationic polymer, which is the second most abundant polymer in nature after cellulose and biopolymer, the most widely used in drug delivery. Chitosan is a linear copolymer polysaccharide consisting of (3 (l-4)-linked 2-amino-2-deoxy-D-glucose (D-glucosamine) and 2-acetamido-2-deoxy-D-glucose (N-acetyl-D-glucosamine) units (Figure 19.5). Chitin is the primary... 

The most prominent cellulose ester produced on the industrial scale is cellulose acetate. The reaction is usually performed with acetic anhydride and with sulfuric acid as a catalyst. To minimize heterogeneities, acetylation is allowed to run nearly to completion, and subsequently partial ester hydrolysis is initiated by the addition of water until a desirable solubility is achieved that corresponds to a DS of about 2.5. Such higher acyl homologues as propanoyl or butanoyl exhibit more thermoplastic properties. Many specialized esters such as chiral (-)-menthyloxyacetates, furan-2-carboxylates, or crown-ether-containing acylates have been prepared on the laboratory scale and characterized by NMR spectroscopy. Various procedures have been applied, using anhydrides and acyl chlorides as acylating agents in combination with such bases as pyridine, 4-dimethylaminopyridine (DMAP), or iV,iV -carbonyldi-imidazole. The substitution pattern of cellulose acetates has also been modified by postchemical enzymatic deacetylation. Cellulose 6-tosylates have been used as activated intermediates for nucleophihc substitution to afford 6-amino-6-deoxy, 6-deoxy, or 6-deoxy-6-halo-celluloses. ... 

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