Novel multi-dimensional heteronuclear NMR techniques for the study of 13C-O-acetylated oligosaccharides:: Expanding the dimensions for carbohydrate structures
Novel multi-dimensional heteronuclear NMR techniques for the study of 13C-O-acetylated oligosaccharides:: Expanding the dimensions for carbohydrate structures
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DOI：
10.1023/a:1008342510795
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发表时间：
1999-10-01
影响因子：
2.7
通讯作者：
Bendiak, B
中科院分区：
文献类型：
--
作者：
Jones, DNM;Bendiak, B
复合碳水化合物在各种生物过程中具有关键作用。理解这些过程的分子机制对于开发基于寡糖的新型治疗策略至关重要。不幸的是，获得较大寡糖（> 10个残基）的详细结构信息可能非常困难，特别是在可用样品量有限的情况下。在这里，我们展示了应用C-13 O-乙酰化结合新的NMR实验，以获得所需的信息来表征寡糖的一级结构。提供了（H）CMeCOH-HEHAHA和H（C-Me）COH-HEHAHA实验，其使用杂环Hartmann-Hahn转移将乙酰基与全乙酰化寡糖中的糖环质子相关联。在这些实验中，相关峰的同相、纯吸收性质允许测量化学位移和重要的用于定义糖环的立体化学的H-1-H-1偶合常数。（HCMe）COH和（HCMe）COH-RELAY实验提供了额外的方法，用于获得较大寡糖的化学位移分配，以根据乙酰化模式确定糖苷键的位点。
Complex carbohydrates have critical roles in a wide variety of biological processes. An understanding of the molecular mechanisms that underlie these processes is essential in the development of novel oligosaccharide-based therapeutic strategies. Unfortunately, obtaining detailed structural information for larger oligosaccharides (> 10 residues) can be exceedingly difficult, especially where the amount of sample available is limited. Here we demonstrate the application of C-13 O-acetylation in combination with novel NMR experiments to obtain much of the information required to characterize the primary structure of oligosaccharides. (H)CMeCOH-HEHAHA and H(C-Me)COH-HEHAHA experiments are presented that use heteronuclear Hartmann-Hahn transfer to correlate the acetyl groups with sugar ring protons in peracetylated oligosaccharides. The in-phase, pure absorption nature of the correlation peaks in these experiments allows measurement of both chemical shifts and, importantly, H-1-H-1 coupling constants that are used to define the stereochemistry of the sugar ring. The (HCMe)COH and (HCMe)COH-RELAY experiments provide additional methods for obtaining chemical shift assignments for larger oligosaccharides to define the sites of glycosidic linkages from the patterns of acetylation.