Preliminary Quality Study Of Platycodon Grandiflorum By Electrochemical Fingerprint And Infrared Spectroscopy Third-order Identification

1 Objective:Taking Platycodon grandiflorum(including Inner Mongolia,Shanxi,Hunan,Anhui)from the four major producing areas as the research object,two methods(electrochemical fingerprint spectroscopy technology combined with systematic clustering analysis and "infrared spectroscopy third-order identification method")are used to analyze the overall chemical information of Platycodon grandiflorum rhizomes,so as to identify and evaluate the different origins of Platycodon grandiflorum.2 Methods:This article uses two methods: One method is the combination of electrochemical fingerprinting technology and systematic cluster analysis,which focuses on the root of Platycodon grandiflorum as a whole,including the epidermis and various components,for identification and differentiation.The other method is the "third-order infrared spectroscopy method",which combines Fourier infrared first-order spectra,second-order derivative spectra and micro-infrared spectroscopy.This method analyzes and identifies the chemical composition content and distribution of Platycodon grandiflorum progressively from point to surface.Both methods focus on the overall concept of Chinese medicine.3 Results:3.1 Using the electrochemical fingerprinting technology combined with the systematic clustering analysis method,the electrochemical fingerprints of Platycodon grandiflorum from nine different producing areas in four major producing areas were studied,and the E-t curve and its main characteristic parameters were used to identify Platycodon grandiflorum medicinal materials.By investigating the influence of temperature,the amount of medicinal materials and rotation speed on the electrochemical oscillation system,the optimal experimental conditions of the system were determined: the temperature was 310 K,the sample amount was 0.1500 g,and the rotation speed was500 r/min.Under the best conditions,the electrochemical fingerprint of Platycodon grandiflorum was determined.Platycodon grandiflorum from nine producing origins differs greatly in chemical composition and substance content due to the differences in the growth environment between the north and the south.Through the study of electrochemical fingerprinting technology,the results show that the E-t curves and main characteristic parameters of Platycodon grandiflorum from different origins are obviously different.3.2 The cluster analysis results show that when the Euclidean distance is 3,the production areas of each province are clustered into one category alone,which can be divided into four categories.This proves that according to the analysis of the geographical distance of different producing areas,the difference in the content and distribution of Platycodon grandiflorum between different provinces is obvious.The results of cluster analysis are the same as those obtained from nonlinear electrochemical fingerprinting.It is proved that the nonlinear electrochemical fingerprint can be used to identify Platycodon grandiflorum from different places.3.3 Fourier infrared spectroscopy combined with second derivative spectroscopy in the identification of Platycodon grandiflorum can not only provide chemical information of the main components contained in Platycodon grandiflorum,but also can identify and distinguish Platycodon grandiflorum from nine production areas in the four major production areas.Infrared spectroscopy can realize rapid identification of Platycodon grandiflorum.Micro-infrared spectroscopy distinguished platycodons from nine origins from a higher level.It can provide image information of the cross-sectional morphological concept of fresh Platycodon grandiflorum rhizome from point to surface,and can provide quantitative information on the composition and content of chemical analysis concepts at the cellular level,so as to achieve semi-quantitative research.Using infrared spectroscopy third-order identification method to identify the nine producing areas of the four major producing areas of Platycodon grandiflorum is effective.3.4 The Fourier infrared spectra of Platycodon grandiflorum from different origins are not significantly different on the whole.After the second derivative processing,the characteristic peak difference of each producing area can be revealed,and the micro-infrared spectrum chart further visually and clearly shows the content and distribution area of platycodin d.This further supports the results of the difference in the content of Platycodin d in Platycodon grandiflorum from different different origins.According to the analysis of the geographical distance of different origins,the difference in the content and distribution of Platycodon grandiflorum between different provinces is quite obvious;at the same time,there is almost no big difference between different cities in the same province.The possible reason is that the geographical distance between different cities in the same province is relatively small.4 Conclusion:4.1 The electrochemical fingerprint is an oscillation curve produced by the interaction of various substances in an oscillating system.Platycodon grandiflorum in the nine production areas of the four major production areas will have different effects on the same oscillation system due to the differences in their cultivation areas.It can be distinguished by the difference between the final oscillation curve and the characteristic parameters.This method not only has good reproducibility,but also contains rich quantifiable and intuitive information.It does not require large-scale instruments,preprocessing,and is simple and easy to implement.The information can be used to analyze the chemical components of Platycodon grandiflorum as a whole for identification or quality evaluation.Cluster analysis further verified that the electrochemical experimental data of different origins of Platycodon grandiflorum have obvious regional classification.At the same time,the characteristic of electrochemical spectroscopy is to analyze Chinese medicine as a whole.It is an effective,simple,fast and economical method,and it is worthy of promotion.4.2 The experiment uses the combination of Fourier infrared first-order spectrum,second-order derivative spectrum and micro-infrared spectroscopy to progressively analyze and identify the content and distribution of chemical components of Platycodon grandiflorum.Obtained the overall structure information of Platycodon grandiflorum from different producing areas,verified the difference in the content and distribution of the content of different producing areas,and initially identified Platycodon grandiflorum from different producing areas.It lays a systematic and complete foundation for the identification and quality evaluation of different Chinese medicines in different places of origin in the future,and also provides new ideas for identifying Chinese medicines that are easy to be confused and have similar sources.It is a direction that can be developed.