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本文报导了十个碳苷化合物的~(13)C-NMR谱,其中四对是α、β端基异构体。研究结果发现,α和β异构体糖环各相应碳原子的~(13)C-NMR的化学位移值有明显差异。β异构体糖环上各碳的化学位移值(除C_4’外)均比α异构体相应碳大,而且各具特征数值。这一规律可用作区分碳苷的端基构型。此外尚讨论了糖的构型对苷元δ_c值的影响。
This paper reports the ~ (13) C-NMR spectra of ten carbon glycosides, of which four pairs are α, β anomers. The results showed that the chemical shifts of ~ (13) C-NMR of the corresponding carbon atoms in the α and β isomer ring were significantly different. The chemical shifts (except for C_4 ’) of the carbons on the β-isomer sugar ring are larger than the corresponding carbons of the α-isomer and each has its own characteristic value. This rule can be used to distinguish the end group configuration of the carbon glycoside. In addition, the effect of sugar configuration on aglycone δ_c was also discussed.