DEACETYLATION OF CHITIN OLIGOSACCHARIDES OF DP 2-4 BY CHITIN DEACETYLASE FROM COLLETOTRICHUM LINDEMUTHIANUM

摘要

Chitin oligosaccharides of degree of polymerization 2-4 were deacetylated by purified chitin deacetylase isolated from Colletotrichum lindemuthianum to give their corresponding breakdown products after purification by liquid chromatography. Data from FABMS analyses suggested that N, N', N '', N'''-tetraacetylchitotetraose and N, N', N ''-triacetylchitotriose were converted into fully-deacetylated corresponding chitosan oligomers. Conversely, N,N'-diacetylchitobiose [(GlcNAc)(2)] was deacetylated to give a product which showed an [M + H](+) pseudomolecular ion at m/z 383, suggesting that either of the two acetyl groups were removed. Further data from H-1 NMR analyses confirmed that the reaction product was 2-acetamido-4-O-(2-amino-2-deoxy-beta-D-glucopyranosyl)-2-deoxy-D-glucose [GlcN-GlcNAc]. The enzymatic method has three advantageous characteristics over chemical methods: (i) it does not cause unexpected degradation of the sugar chain, (ii) it is highly reproducible, and (iii) unique compounds such as GlcN-GlcNAc may be produced. (C) 1997 Elsevier Science Ltd. [References: 20]