Preparation and Reactivity of an Alcohol Dehydrogenase-NADH Model

作为醇脱氢酶-NADH偶联的模型，通过N-[ω-（9-（6-羟基己基）嘌呤-6-基氨基）烷基]烟酰胺（a，烷基=丁基; B，戊基; c，己基）的羟基碘化，然后环化为吡啶盐并还原，制备了一系列大环1，4-二氢烟酰胺1a-c连接的腺嘌呤。用紫外光谱和核磁共振氢谱研究了1b，c与镁离子在乙腈中的配位行为，并与1-甲基-3-（N-甲基氨基甲酰基）-1，4-二氢吡啶（2）和1-[6-（6-甲氨基-9H-嘌呤-9-基）]己基-3-（N-甲基氨基甲酰基）-1，4-二氢吡啶（3）的配位行为进行了比较。在1b，c中的腺嘌呤部分加速镁离子在二氢烟酰胺部分的络合，推测是通过充当π电子供体。在高氯酸镁存在下，1a-c、2和3与苯甲酰甲酸甲酯反应的动力学研究表明，在所测试的条件下，反应顺序为1b&gt;1a&gt;3 <greater than or equal>1c&gt;2

As a model for alcohol dehydrogenase-NADH couple, a series of macrocyclic 1, 4-dihydronicotinamides 1a-c linked adenine was prepared via N-[omega-(9-(6-hydroxyhexyl) purin-6-ylamino) alkyl]nicotinamide (a, alkyl = butyl ; b, pentyl ; c, hexyl) by iodination of the hydroxyl group followed by cyclization to the pyridinium salt and reduction. The coordination behavior of 1b, c with magnesium ion in acetonitrile was investigated by ultraviolet and ^1H-NMR spectroscopies, and compared with those of 1-methyl-3-(N-methylcarbamoyl)-1, 4-dihydropyridine (2) and 1-[6-(6-methylamino-9H-purin9-yl) lhexyl-3-(N-methylcarbamoyl)-1, 4-dihydropyridine (3). The adenine moiety in 1b, c accelerates complexation of magnesium ion at the dihydronicotinamide moiety, presumably by acting as a pi electron donor. The reactivity of 1a-c, 2, and 3 toward methyl benzoylformate in the presence of magnesium perchlorate in acetonitrile was kinetically investigated and found to be of the order 1b>1a>3<greater than or equal>1c>2 under the conditions teste