Einosuke Muraki

Production of N-acetyl-D-glucosamine from α-chitin by crude enzymes from Aeromonas hydrophila H-2330

The selective and efficient production of N-acetyl-D-glucosamine (GlcNAc) was achieved from flake type of alpha-chitin by using crude enzymes derived from Aeromonas hydrophila H-2330.

Enzymatic production of N-acetyl-D-glucosamine from chitin. Degradation study of N-acetylchitooligosaccharide and the effect of mixing of crude enzymes

N-Acetyl-D-glucosamine (GlcNAc) was produced from chitin by use of crude enzyme preparations. The efficient production of GlcNAc by cellulases derived from Trichoderma viride (T) and Acremonium cellulolyticus (A) was observed by HPLC analysis compared to lipase, hemicellulase, and pectinase. b-Chitin showed higher degradability than a-chitin when using cellulase T. The optimum pH of cellulase T was 4.0 on the hydrolysis of b-chitin. The yield of GlcNAc was enhanced by mixing of cellulase T and A. q 2003 Elsevier Science Ltd. All rights reserved.

Chemical modification of chitosan. Part 15: Synthesis of novel chitosan derivatives by substitution of hydrophilic amine using N-carboxyethylchitosan ethyl ester as an intermediate

The Michael type reaction of chitosan with ethyl acrylate has been investigated. Although this reaction was quite slow in the case of chitosan, the reiteration of the reaction was an effective means for increasing the degree of substitution (DS) of ethyl ester. The N-carboxyethylchitosan ethyl ester as an intermediate was successfully substituted with various hydrophilic amines, although the simultaneous hydrolysis of the ester to carboxylic acid also occurred. Water-soluble chitosan derivatives were obtained by substitution with hydroxyalkylamines and diamines.

Preparation and crystallization of d-glucosamine oligosaccharides with dp 6-8

Abstract d -Glucosamine oligosaccharides of degree of polymerization 5–9 were separated from a chitosan hydrolyzate prepared with the cellulase of Trichoderma viride . Separation was accomplished by prefractionation with methanol-water and chromatography on a weak acid ion-exchanger, with elution by 0.01 N HCl. Penta- to nona-saccharides comprised almost half of the total product. The hexa-hepta-, and octa-saccharides were crystallized from dilute HCl solutions as their hydrochloride salts. Conductometric titration to determine the glucosamine content and elemental analysis showed that this procedure is effective for the preparation of highly pure oligosaccharides.