Identification of Coptis chinensis and rhubarb by infrared spectroscopy

Abstract: a unified extraction and separation method was used to treat the plant medicine, and then the infrared spectrum of the extract was determined The infrared spectrum of plant medicine obtained by this method has high characteristics and repeatability In this paper, Huanglian and rhubarb as pour, through the comparative test and analysis of the Chinese medicine and biological products provided by the control and the author collected medicine, to show the unique identification effect of this method It is very intuitionistic, convenient and accurate to judge the attribution of the samples by the degree of the agreement of the infrared spectrum of the reference and the samples The data of infrared spectrum of plant medicine can be input into computer and retrieved by computer Key words: infrared spectroscopy; identification; Coptis chinensis; Rhubarb; botanical drugs at present, the varieties and authenticity of botanical drugs at home and abroad mainly rely on morphological identification Once the morphology is damaged, it is difficult to identify Some medicinal materials are difficult to identify clearly even by throwing a microscope and physical and chemical methods This method can solve the problem of extraction and infrared sample preparation of plant medicine and make it widely used in the identification of various plant medicine This method mainly reflects and studies the differences between medicinal materials from the perspective of chemical composition Therefore, this method can be used as a supplement to the traditional morphological identification method The combination of the two methods can make the identification method of plant medicine more perfect, more accurate and more scientific Materials and methods the instrument perkin-elmer783 infrared spectrophotometer is equipped with 3600 special computer The resolution of spectrum determination is 5.4/cm slit program, and four instantaneous averages are taken Methods: the single plant medicine was smashed, sieved, weighed (1g), extracted with solvent, extracted with fat soluble and water soluble extract, prepared with infrared method, scanned with infrared spectrogram, processed with data and put into computer retrieval spectral database Results the two spectra connected up and down came from the two parts of the same medicinal material The spectrum of fat soluble extract in the top picture and the spectrum of water soluble extract in the bottom picture All the pictures are infrared spectra of Weilian The spectral profiles of the two liposoluble compounds are similar but different The peak positions of 35 absorption peaks of the two water-soluble compounds are identical (the threshold value of the peak value listed by computer is 1t%) Although we don't know whether they have the same origin and collection period, we can roughly determine whether they belong to the same kind of medicinal material according to the degree of spectral coincidence Infrared spectra of the other three species of Coptis The spectra of different species of Coptis are so similar, which shows that their chemical components are very similar Wild Coptis has not been included in the Pharmacopoeia of the people's Republic of China due to its small drug source, but its chemical composition is basically consistent with that of Coptis chinensis from the perspective of spectrum There are differences in the spectrum of fat soluble matter between the two rhubarb species The spectrum of water soluble matter is very similar except for the absorption peak difference of 29 / cm near 1200 / cm However, according to the above differences, the two rhubarb species can be accurately distinguished Spectrum of two kinds of fake rhubarb Compared with Rheum palmatum, their liposoluble spectra are similar, but their water soluble spectra are different For example, the absorption peak of the water-soluble substance spectrum of Hetao rhubarb is weak near 1700 / cm, the difference between the absorption peaks near 1200 / cm is 60 / cm, there is one more absorption peak at 963 / cm, and the peak shape and position of a group of small peaks near 800 / cm are different Because the chemical components of rhubarb are quite different, it is easy to find the identification basis from the spectrum Shandong Heze medicine Station has a batch of rhubarb due to poor appearance want to return This batch of rhubarb was identified by Shandong Institute of drug control as rhubarb Fig 10 is the infrared spectrum of this batch of Rhubarb Samples Although the origin and collection period of the sample are not clear, its spectrum has the spectral characteristics of rhubarb and is consistent with that of rhubarb According to its spectral characteristics, it can be considered that the sample belongs to rhubarb and can be generally identified as Rheum palmatum The lateral root of rhubarb is known as "water root rhubarb" The spectral profile of the picture is similar to that of rhubarb, but different from that of the fake rhubarb Therefore, it can be concluded that the chemical composition of rhubarb is similar to that of rhubarb It can be seen that this method can be used for the general survey and screening of new drug sources in the same family If the spectrum of a plant is similar to that of a drug rejection plant, the plant may have a drug rejection value similar to that of a drug rejection plant The characteristics of this method are as follows: 1 The commonly used economic and low toxic solvent is used, the method is simple, the result is accurate, the repeatability is high, and the whole operation takes about 5 hours 2 Infrared spectrophotometer is a common analytical instrument, which is easy to popularize 3 If the difference of chemical composition between samples is more than 2 (the main absorption peak is not covered), it is possible to observe the change of infrared spectrum Therefore, all the factors that can cause the quality change of medicinal materials can be studied by this method 4 The establishment of this method has laid a solid foundation for further research on the infrared spectrum of standard botanical drugs (scientific name, origin, accurate collection season, standard processing method) Once the infrared spectrum of the standard botanical medicine is available, the spectrum of the sample can be compared with it to make accurate identification Discussion 1 Because of the uniform extraction method, the chemical components in the extracts of plant medicine must be relatively stable Therefore, the measured spectral data must have high comparability and repeatability For the same sample, the spectrum of each measurement can be consistent (the wave number error is within the error range of the instrument) For different samples of the same kind of medicinal materials, the accuracy of most absorption peaks in the spectrum is also within the accuracy range of the wave number of the instrument (such as the comparison of medicinal materials and Weilian collected by the author) Therefore, the reproducibility of this method is very high 2 The spectral data in this paper is only for preliminary demonstration of the identification effect of this method Therefore, there is not enough sample collection There are not enough aspects involved The author has tested Pueraria and artichoke in different collecting periods and Codonopsis pilosula in different producing areas The preliminary experimental results show that the spectral differences caused by different producing areas and collecting periods are generally smaller than those caused by different plants of the same family, that is to say, the differences of the chemical components of the species smell are generally larger than those caused by different producing areas and collecting periods Therefore, the spectral data and their analysis listed in this paper are preliminarily based In addition, some aspects of this method need to be further explored and studied Reference (1) Tian Jinguo et al Preliminary study on identification of Chinese herbal medicines by infrared spectroscopy Chinese herbal medicine 1989; 20 (5), 221 (2) Institute of medicine, Chinese Academy of Medical Sciences, et al Chinese herbal medicine Vol 1 Beijing People's Health Press, 1979, 31