Hermansson K, Jansson P E, Kenne L, Widmalm G, Lindh F
Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, Sweden.
Carbohydr Res. 1992 Nov 4;235:69-81. doi: 10.1016/0008-6215(92)80079-g.
Several oligosaccharides from human milk, containing vicinally branched residues, have been analysed with respect to induced NMR chemical shift changes that originate from the branching. Two types of branching were investigated: (i) linear oligosaccharides with a 2-linked residue, which thus becomes vicinally 1,2-disubstituted, and (ii) oligosaccharides with either 2,3- or 3,4-branching. It could be concluded that, in 13C NMR spectra of the first type, for which only moderately sized induced changes (< 2 ppm) had been observed previously, large (> 5 ppm) changes are also present. For 2,3- and 3,4-branching, changes similar to those observed earlier were found. In 1H NMR spectra, significant induced shifts for signals from anomeric, aglyconic, and H-5 protons were observed. For most trisaccharides, a unique set of values for the chemical shift differences was found, thus making it suitable to use them for characterisation of substitution patterns in the analysis with the computer program CASPER.
对几种来自人乳的含有邻位分支残基的低聚糖，就其因分支而引起的核磁共振化学位移变化进行了分析。研究了两种类型的分支：（i）带有一个2-连接残基的线性低聚糖，因此该残基变为邻位1,2-二取代的，以及（ii）具有2,3-或3,4-分支的低聚糖。可以得出结论，在第一类的13C核磁共振谱中，此前仅观察到适度大小的诱导变化（<2 ppm），现在也存在大的（>5 ppm）变化。对于2,3-和3,4-分支，发现了与早期观察到的类似变化。在1H核磁共振谱中，观察到了来自异头质子、苷元质子和H-5质子信号的显著诱导位移。对于大多数三糖，发现了一组独特的化学位移差值，因此适合在使用计算机程序CASPER进行分析时用它们来表征取代模式。
