Striegler Susanne, Dittel Michael
Division of Inorganic Chemistry II, University of Ulm, Albert-Einstein-Allee 11, D-89069 Ulm, Germany.
J Am Chem Soc. 2003 Sep 24;125(38):11518-24. doi: 10.1021/ja035561f.
We investigated the complex formation between various underivatized carbohydrates and the binuclear copper(II) complex 1, Cu(2)(bpdpo). A combined approach of UV/vis and CD spectroscopic investigations shows a large discrimination ability of 1 for structurally closely related monosaccharides in alkaline solution. The dominating form of the binuclear copper(II) complex consists of a Cu(2)L(-)(H)(OH)(2) species between pH 11 and 13, as determined from pH-dependent spectrophotometric titration experiments. The binding strengths of the 1:1 sugar-1 complexes, derived from the biologically important monosaccharides d-mannose (3) and d-glucose (5), is about 1.5 orders of magnitude different at pH 12.40. Moreover, a blue- or a red-shift of the absorption maximum of 1 accompanies the sugar binding and highlights the ability of 1 to discriminate carbohydrates. This phenomenon is due to the number of hydroxyl groups of the particular monosaccharide involved in chelation to the binuclear metal complex.
我们研究了各种未衍生化的碳水化合物与双核铜（II）配合物1，即Cu(2)(bpdpo)之间的配合物形成情况。紫外/可见光谱和圆二色光谱研究相结合的方法表明，在碱性溶液中，1对结构密切相关的单糖具有很大的区分能力。根据pH依赖的分光光度滴定实验确定双核铜（II）配合物的主要形式在pH值11至13之间为Cu(2)L(-)(H)(OH)(2)物种。在pH 12.40时，源自具有生物学重要性的单糖d-甘露糖（3）和d-葡萄糖（5）的1:1糖-1配合物的结合强度相差约1.5个数量级。此外，1的吸收最大值的蓝移或红移伴随着糖的结合，并突出了1区分碳水化合物的能力。这种现象是由于参与与双核金属配合物螯合的特定单糖的羟基数量所致。
