Based on infrared spectrum to study the changes in the intrinsic chemicalcomponents in Trichosanthes before and after steaming / 国际药学研究杂志

ABSTRACT

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.