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提出以原子电性距离矢量 (VAED) ,描述上百种糖分子中数百个不同等价碳原子的化学环境 ;并结合γ效应校正 ,建立核磁共振碳谱 ( 1 3CNMR)化学位移 (CS)的五参数线性模型 .用于糖分子中四类不同的等价碳原子化学位移的估计 ,复相关系数R和均方根误差RMS及标准偏差SD和F -统计量F分别为 :伯碳n=62 ,R =0 .991 0 ,RMS =1 .960 2 (SD =1 .9762 ,F =5 0 2 .32 94 ,EV =0 .980 5 ) ;仲碳n=79,R =0 .9886,RMS=2 .5 40 5 (SD =2 .5 5 67,F=5 1 5 .60 4 6,EV =0 .975 7) ;叔碳n=30 2 ,R=0 .95 1 4 ,RMS =3.6884 (SD=3.694 5 ,F=4 68.82 76,EV =0 .90 35 )及季碳n =1 4 ,R=0 .5 772 ,RMS=8.862 6(SD =9.1 972 ,F =0 .5 82 8,EV =- 0 .0 837) .经交互校验 ,伯仲叔碳的化学位移模型稳定性较好 .并综合几种处理方法 ,找到一种较好的建模方法 ,将它用于几个外部样本的定量预测 ,结果良好 .
In this paper, the chemical environment of hundreds of different equivalent carbon atoms in hundreds of sugar molecules is described by the atomic valence distance vector (VAED). In combination with the γ effect correction, a 13 C NMR chemical shift (CS) , Which is used to estimate the chemical shifts of four different equivalent carbon atoms in the sugar molecule, the complex correlation coefficient R and root mean square error RMS and standard deviation SD and F - statistics F are respectively: primary carbon n = 62, R = 0.991 0, RMS = 1 .9602 (SD = 1 .9762, F = 5 0 2 .32 94, EV = 0 .980 5); secondary carbon n = 79, R = 0. 9886, RMS = 2.55405 (SD = 2.5567, F = 5 15.660 4 6, EV = 0.975 7); tertiary carbon n = 30 2, R = 0.95 1 4 , RMS = 3.6884 (SD = 3.694 5, F = 4 68.82 76, EV = 0.90 35) and quaternary carbon n = 1 4, R = 0.5772, RMS = 8.862 6 (SD = 9.1 972, F = 0 .5 82 8, EV = - 0.0837) .Based on the cross-validation, the chemical shift model of primary and tertiary carbon is more stable, and by combining several treatment methods, a better modeling method It is used for the quantitative prediction of several external samples and the result is good.