AND SUMMARYA method (DMF-Methylate method) has been described for the homolog analysis of cationic and amphoteric surfactants having a quaternary ammonium group. The homolog distribution of cationic and amphoteric surfactants obtained by the DMF-Methylate method closely agrees with that of the original alkyldimethylamines used. Therefore, the DMF-Methylate method should be applicable to the homolog analysis of these surfactants. This method also offers qualitative information for the identification of these surfactants, since the ratio of the 0tolefin to the alkyldimethylamine varies with each surfactant. On the basis of the analysis of the elimination products, it was confirmed that the main degradation process was the elimination of a P-hydrogen atom. This mechanism is different from that of the pyrolysis gas chromatography, which will be discussed elsewhere (S. Takano, M. Kuzukawa, and M. Yamanaka, in preparation).amines formed by the catalytic hydrogenation with palladium-carbon. Also, Kojima et al. (6) reported a similar reductive method with lithium aluminum hydride and sodium borohydride. Jennings et al. (7) reported a modified Hofmann degradation, which was carried out with 4Npotassium hydroxide in a sealed glass tube, for the analysis of alkylbenzyldimethylammonium chlorides.However, no paper has been reported on the homolog analysis of amphoteric surfactants, so we tried to apply the Hofmann degradation to it. Usually, the Hofmann degradation is conducted by treating the sample with silver oxide and heating under reduced pressure. However, these procedures seemed to be too tedious for an analytical routine work. Therefore, in this study, the degradation method, which was used in the synthesis of aldosterone by Wolff et al. (8), was investigated and improved.By this method, not only cationic but also amphoteric surfactants can be readily degraded to give chiefly a-olefins and alkyldimethylamines. Their homolog distributions could be determined by the peak areas of the alkyldimethylamines formed by gas chromatography.

Chitooligosaccharides exhibit several biomedical activities, such as inflammation and tumorigenesis reduction in mammals. The mechanism of the chitooligosaccharides’ formation in vivo has been, however, poorly understood. Here we report that mouse acidic chitinase (Chia), which is widely expressed in mouse tissues, can produce chitooligosaccharides from deacetylated chitin (chitosan) at pH levels corresponding to stomach and lung tissues. Chia degraded chitin to produce N-acetyl-d-glucosamine (GlcNAc) dimers. The block-type chitosan (heterogenous deacetylation) is soluble at pH 2.0 (optimal condition for mouse Chia) and was degraded into chitooligosaccharides with various sizes ranging from di- to nonamers. The random-type chitosan (homogenous deacetylation) is soluble in water that enables us to examine its degradation at pH 2.0, 5.0, and 7.0. Incubation of these substrates with Chia resulted in the more efficient production of chitooligosaccharides with more variable sizes was from random-type chitosan than from the block-type form of the molecule. The data presented here indicate that Chia digests chitosan acquired by homogenous deacetylation of chitin in vitro and in vivo. The degradation products may then influence different physiological or pathological processes. Our results also suggest that bioactive chitooligosaccharides can be obtained conveniently using homogenously deacetylated chitosan and Chia for various biomedical applications.

Chitooligosaccharides, the degradation products of chitin and chitosan, possess anti-bacterial, anti-tumor, and anti-inflammatory activities. The enzymatic production of chitooligosaccharides may increase the interest in their potential biomedical or agricultural usability in terms of the safety and simplicity of the manufacturing process. Crab-eating monkey acidic chitinase (CHIA) is an enzyme with robust activity in various environments. Here, we report the efficient degradation of chitin and chitosan by monkey CHIA under acidic and high-temperature conditions. Monkey CHIA hydrolyzed α-chitin at 50 °C, producing N-acetyl-D-glucosamine (GlcNAc) dimers more efficiently than at 37 °C. Moreover, the degradation rate increased with a longer incubation time (up to 72 h) without the inactivation of the enzyme. Five substrates (α-chitin, colloidal chitin, P-chitin, block-type, and random-type chitosan substrates) were exposed to monkey CHIS at pH 2.0 or pH 5.0 at 50 °C. P-chitin and random-type chitosan appeared to be the best sources of GlcNAc dimers and broad-scale chitooligosaccharides, respectively. In addition, the pattern of the products from the block-type chitosan was different between pH conditions (pH 2.0 and pH 5.0). Thus, monkey CHIA can degrade chitin and chitosan efficiently without inactivation under high-temperature or low pH conditions. Our results show that certain chitooligosaccharides are enriched by using different substrates under different conditions. Therefore, the reaction conditions can be adjusted to obtain desired oligomers. Crab-eating monkey CHIA can potentially become an efficient tool in producing chitooligosaccharide sets for agricultural and biomedical purposes.