Synthesis of Enantiomerically-Pure [13C]Aristeromycylcobalamin and Its Reactivity in Dioldehydratase, Glyceroldehydratase, Ethanolamine Ammonia-Lyase and Methylmalonyl-CoA Mutase Reactions
作者:Ulrich Weigl、Martin Heimberger、Antonio J. Pierik、János Rétey
DOI:10.1002/chem.200390073
日期:2003.2.3
We describe a novel enantioselective synthesis of aristeromycin, the carbocyclic analogue of adenosine. The seven-step synthesis is also suitable for the preparation of specifically-labelled [6'-(13)C]aristeromycin. Both the unlabelled and (13)C-labelled product was coupled to vitamin B(12) to form aristeromycylcobalamin. This carbocyclic analogue of coenzyme B(12) was examined for its coenzymic activity
我们描述了一种新的对映选择性合成的阿霉素,腺苷的碳环类似物。七步合成法也适用于制备特异性标记的[6'-(13)C]阿霉素。未标记的和(13)C标记的产品均与维生素B(12)偶联形成阿霉素。检查了辅酶B(12)的这种碳环类似物与几种腺苷钴胺素依赖性酶的辅酶活性。对于甘油二脱水酶和二醇脱水酶,反应速率(k(cat))为以腺苷钴胺素为辅酶测得的反应速率的38%和44%。相比之下,aractomycylcobalamin对甲基丙二酰辅酶A变位酶和乙醇胺氨裂解酶未显示可检测的活性。相反,它是前一种酶的弱抑制剂和后一种酶的强抑制剂。甘油三糖水合酶的较慢周转率提高了检测6'-脱氧花生四烯酸自由基中间体的希望。分别使用腺苷基和阿霉素基钴胺作为辅酶的甘油三水合酶反应中间产物的EPR谱进行比较,结果显示了显着变化,这表明这些辅因子在碳原子裂解过程中在结合位点处具有不同的几何位置。钴键。但是,我们没有发现与[6'-(13)C]