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N-羧酰咪唑作为酰化试剂单独与核糖核苷酸吡啶盐反应时,主要形成核糖核苷-2′,3′-环磷酸或其与羧酸的混合酸酐,但是当有 N,N′-二环已基吗福啉碳酰胺亚胺或无水氢氧化四乙基铵存在时,不仅可以抑制核苷酸的2′,3′-环磷酰化,而且大大加快了核糖羟基和杂环氨基的酰化反应速度和反应的完全程度.羧酰咪唑试剂已应用于各种核糖核苷酸的乙酰化、异丁酰化、苯甲酰化反应.与羧酸酐和苯甲酰氰相比较,本试剂的优点在于反应速度快,副反应少,产物纯,得率高.根据产物的分离和鉴定以及~(31) P 脉冲核磁共振谱的变化初步证明,当苯甲酰咪唑与3′-尿核糖核苷酸吡啶盐在二甲基甲酰胺中反应时,一般情况下先迅速形成核苷酸-苯甲酸的混合酸酐,然后转化为核苷-2′,3′-环磷酸,再进一步完成5′-羟基的苯甲酰化.若有 N,N′-二环已基吗福啉碳酰胺亚胺或氢氧化四乙胺存在时,则核糖核苷酸的杂环氨基和核糖部分上的羟基都发生酰化,而且形成混合酸酐但不出现环核苷酸.
When N-carboxyimidazole is used alone as the acylation reagent to react with the ribonucleoside pyridinium salt, ribonucleoside-2 ’, 3’-cyclic phosphoric acid or its mixed acid anhydride with carboxylic acid is mainly formed, but when N, N’ - dicyclohexylcarbophil carbonamide or anhydrous tetraethylammonium hydroxide in the presence of not only inhibit 2 ’, 3’-ring phosphorylation of nucleotides, but also greatly accelerated the ribose hydroxyl and miscellaneous Acylamino acylation reaction speed and the degree of completeness.Carboxyimidazole reagents have been used in a variety of ribonucleotide acetylation, isobutyrylation, benzoylation reaction with carboxylic anhydride and benzoyl cyanide phase The advantages of this reagent are that the reaction speed is fast, the side reaction is less, the product is pure and the yield is high.According to the separation and identification of the product and the change of ~ (31) P pulsed nuclear magnetic resonance spectrum, ’- urinary ribonucleotide pyridine salt reaction in dimethylformamide, under normal circumstances quickly form nucleotide - benzoic acid mixed anhydride, and then converted into nucleoside -2’, 3’-cyclic phosphate, Further completion of the 5’-hydroxybenzoylation.If there N, N’-dicyclohexyl basophil carboxamide imide or tetraethylammonium hydroxide When present, both the heterocyclic amino group of the ribonucleotide and the hydroxyl group of the ribose moiety are acylated, and a mixed anhydride is formed but cyclic nucleotides do not appear.