Synthesis and Evaluation of Potential Inhibitors of Chondroitin AC Lyase from <i>Flavobacterium </i><i>h</i><i>eparinum</i>
作者:Carl S. Rye、Stephen G. Withers
DOI:10.1021/jo020089m
日期:2002.6.1
Flavobacterium heparinum degrades chondroitin sulfate glycosaminoglycans via an elimination mechanism, resulting in disaccharides or oligosaccharides with Delta4,5-unsaturated uronic acid residues at their nonreducing end. The syntheses and testing of two potential inhibitors of this lyase are described. Methyl O-(2-acetamido-2-deoxy-beta-D-galactopyranosyl)-(1-->4)-alpha-L-threo-hex-4-enopyranoside, 1
肝黄杆菌中的软骨素AC裂解酶通过消除机制降解硫酸软骨素糖胺聚糖,产生在其非还原端带有Delta4,5-不饱和糖醛酸残基的二糖或寡糖。描述了该裂解酶的两种潜在抑制剂的合成和测试。甲基O-(2-乙酰氨基-2-脱氧-β-D-吡喃并吡喃糖基)-(1> 4)-α-L-苏-hex-4-enopyranoside,1在uronic的C5处具有三角几何形状预期在过渡态的酸部分,但仍保留“离去基”糖部分。出人意料的是,化合物1没有显示出对该酶的抑制。新型5-硝基糖苯基(5S)-5-硝基-β-D-吡喃吡喃糖苷2是天然底物的单糖硝基类似物,C5为pK(a)8.8的碳酸。在此中心生成的阴离子的质子化率足够低,以至于阴离子2可以直接用于初始稳态速度测量中,而不会受到共轭碳酸的明显干扰。发现化合物2的阴离子是竞争性抑制剂,其K(i)值为5mM,而共轭酸的K(i)值为35mM。