Studies on the Syntheses of Bioactive Chitin Derivatives.

制备了多种甲壳素衍生物，并对其抗原性、生物降解性和血液相容性进行了人工控制。在各种脱乙酰几丁质中，70%去乙酰几丁质（DAC-70）具有相对长效的免疫佐剂活性，而在80%羧甲基几丁质（GLcNAc残基的C-6位置取代）和各种取代羧甲基几丁质(CM)-几丁质中发现了短效免疫佐剂。DACs的免疫佐剂活性似乎在羧甲基化或o - n -磺化后消失。cm -几丁质的免疫佐剂性质被认为与dac有很大的不同，并且通过去乙酰化、在C-3位置进一步羧甲基化或o -磺化而消失。cm -几丁质作为半抗原载体，在有Freund's完全佐剂的情况下诱导半抗原特异性抗体的产生，在没有Freund's完全佐剂的情况下作为控释药物载体。当在C-6和一些C-3位置的羟基上进行硫酸酸化时，70%去乙酰化-60% cm -几丁质转化为血液相容的，不可生物降解的材料。初步试验发现，将这些cm -甲壳素类肝素注入大鼠静脉后，没有毒性。

Various chitin derivatives were prepared to investigate the artificial control of antigenicity, biodegradabillity and blood compatibility for a biomedical applications. A relatively long-acting immunoadjuvant activity was achieced by 70% deacetylated chitin(DAC-70) among variously deacetylated chitins, and a short-acting immunoadjuvant was found in 80% carboxymethylated chitin(substituted at C-6 position of the GLcNAc residues) and also among variously substituted carboxymethyl(CM)-chitins. The immunoadjuvant activity of DACs seems to disappear upon carboxymethylation or O-N-sulfations. The immunoadjuvant property of CM-chitins was assumed to be fairly different from those of DACs and also disappeared by deacetylation, further carboxymethylation at the C-3 position, or by O-sulfation. CM-chitin was demonstrated to act as a hapten carrier which induced hapten specific antibody production in the presence of Freund's complete adjuvant, and as a controlled-release drug carrier in the absence of Freund's complete sdjuvant.A 70% deacetylated-60%-CM-chitin was converted to a blood compatible, nonbiodegradable material when it was sulfated on the hydroxyl groups at C-6 and on some of the C-3 position. A preliminary test found no toxicity of these CM-chitin heparinoids, when they were injected into rat veins.