A conformational study of methyl β-cellobioside-d8 by 13C nuclear magnetic resonance spectroscopy: dihedral angle dependence of 3JC–H in 13C—O—C—1H arrays
A conformational study of methyl β-cellobioside-d8 by 13C nuclear magnetic resonance spectroscopy: dihedral angle dependence of 3JC–H in 13C—O—C—1H arrays
复制标题
通过 13C 核磁共振波谱研究甲基 β-纤维二糖苷-d8 的构象：13C-O-C-1H 阵列中 3JC-H 的二面角依赖性
DOI：
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发表时间：
1978
期刊：
影响因子：
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通讯作者：
A. Perlin
中科院分区：
文献类型：
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作者：
G. Hamer;F. Balza;N. Cyr;A. Perlin
在Raney镍催化下，β-纤维二糖甲酯（2）的C-2，-3，-3 ′，-4，-6，-6 ′位与氘代物发生氘代反应。在13 C核磁共振光谱的这种同位素标记的化合物得到的简化，促进了残基间13 C-1H耦合的测量，作为一种手段，确定在2中的糖苷键的方向。13 C-4 ′和H-1之间的三键耦合为4.3 Hz，13 C-4 ′和H-1之间为4.2 Hz。 通过参考其他13 C-1H偶联数据，其显示了3JC-H的大小与13 C-O-C-1H键合原子阵列中的二面角之间的Karplus型关系，似乎二糖在水溶液中的扭转角和θ在25 - 30 °的范围内，即，接近晶体2的角度。七-O-乙酰基衍生物的相应数据表明，δ小了10 °，但没有变化。环己己基多烯类化合物的1H-偶合13C光谱分析
Methyl β-cellobioside (2) has been deuterated at positions C-2, -3, -3′, -4, -6, and -6′ by 1H–2H exchange with deuterium oxide in the presence of Raney nickel catalyst. The resulting simplification in the 13C nmr spectrum of this isotopically-labelled compound has facilitated the measurement of interresidue 13C–1H coupling, as a means of determining the orientation of the glycosidic linkage in 2. Three-bond coupling across the linkage between 13C-4′ and H-1 is found to be 4.3 Hz and that between 13C-4′ and H-1, 4.2 Hz. By reference to other 13C–1H coupling data, which exhibit a Karplus type of relationship between the magnitude of 3JC—H and dihedral angle in 13C—O—C—1H arrays of bonded atoms, it appears that torsion angles and ψ of the disaccharide in aqueous solution are in the region of 25–30°, i.e., close to the angles of crystalline 2. Corresponding data for the hepta-O-acetyl derivative indicate that ψ is smaller by ∼10° and is unchanged. An analysis of the 1H-coupled 13C spectrum of cyclohexaamylos...