基于红外光谱研究瓜蒌蒸制前后内在化学成分类别的变化

摘要

Objective To analyze the change in infrared(IR)spectral information and to screen out the classification of major compounds affecting information difference in IR spectra of Trichosanthes before and after steaming. Methods The similarity between the original IR fingerprint and the first derivative IR fingerprint of Trichosanthes and their steamed products was calculated by using the Computer Aided Similarity Evaluation System. The principal component analysis(PCA)model and the partial least squares dis-criminant analysis(PLS-DA)model of IR spectral data of Trichosanthes before and after steaming were established by using SIMCA-P 11 statistical software for PCA and PLS-DA,and the classification of major compounds affecting information difference in IR spectra of Trichosanthes before and after steaming was selected by 3D scatter plot,load 3D scatter plot and variable important in project(VIP) value. Results The similarity between the original IR fingerprint and first derivative IR fingerprint of Trichosanthes and their steamed products were 0.9165 and 0.2832. Seven VIP>1 spectral peaks were screened out by using SIMCA-P 11 statistical software,of which,the absorption peak of 1456 cm-1 was νc=c,the absorption peak of 1726 cm-1 was νc=o and the VIP values were 1.6290 and 1.4256 respectively. Conclusion The categories of compounds of Trichosanthes before and after steaming did not change,but the chemical components changed. Compounds of Trichosanthes before and after steaming affect the difference in IR spectral information may mainly contain C=C-C=C or C=O or both of them.%目的 分析瓜蒌蒸制前后红外光谱信息的变化,筛选影响瓜蒌蒸制前后红外光谱信息差异的主要化合物类别.方法 采用计算机辅助相似性评价系统计算瓜蒌及其蒸制品的原始及一阶导数红外光谱指纹图谱相似度.采用SIMCA-P 11.0统计软件进行主成分分析(PCA)及偏最小二乘判别分析(PLS-DA),建立瓜蒌蒸制前后红外光谱数据的PCA模型和PLS-DA模型,通过得分散点3D图和载荷散点3D图及变量权重值(variable important in project,VIP)值,筛选影响瓜蒌蒸制前后内在红外光谱信息差异的主要化合物类别.结果 瓜蒌及其蒸制品的原始及一阶导数红外光谱指纹图谱的相似度分别为0.9165和0.2832.采用SIMCA-P 11.0统计软件筛选出7个VIP>1的光谱峰,其中1456 cm-1处的吸收峰为νc=c,1726 cm-1处的吸收峰为νc=o且VIP值分别为1.6290和1.4256.结论 瓜蒌蒸制前后化合物类别没有变化,但化学成分发生了变化.影响瓜蒌蒸制前后红外光谱信息差异的化合物中应主要含有C=C-C=C或C=O,或二者兼有.