基于双指标分析法的新疆产罗布麻红外光谱指纹图谱研究

罗布麻作为新疆的特色常用药材，主要用于肝阳眩晕、心悸失眠、浮肿尿少以及高血压、抑郁症的治疗。为保证临床用药安全稳定，常用传统的四大鉴别方法和现代的色谱、波谱技术分析中药材的质量差异。采用傅里叶变换红外光谱（FTIR）法对收集的17份新疆不同产地罗布麻药材进行分析，红外光谱扫描范围为4 000~400 cm-1，二阶导数范围为1 800~600 cm-1，得到图谱后进行图谱解析；采用谱带较密集的指纹区（1 800~400 cm-1）计算红外光谱图的相关系数；然后结合红外光谱吸收峰系统聚类、共有峰率和变异峰率双指标序列分析法对不同产地罗布麻药材的红外指纹图谱进行分类和异同点比较。结果表明，不同产地罗布麻药材红外光谱的峰形、峰位相似，在3 336，2 920，1 443，1 375，1 247，1 103，1 070，833和601 cm-1附近均有吸收，在1 103，1 070和1 656~1 609 cm-1处均存在特征宽强峰。892和717 cm-1处为CO2-₃振动峰，并且仅克拉玛依独山子区药材S4和产地相邻的乌苏市甘家湖保护区药材S5出现此吸收峰，推测与土壤盐碱化程度高有关。除了S5，其余16批罗布麻药材的相似系数均大于0.960，整体相似度较高，说明不同产地罗布麻药材具有一定的相似性。经求导，发现二阶导数光谱的峰形仍具有较大的相似性，但在1 444~1 738和833~1 030 cm-1范围内峰数明显增加。采用SPSS 21.0软件以各药材吸收波数为变量进行聚类分析，S9与S14，S2与S10，S3与S8，S12与S13最先聚为一类；当欧式距离为15时，可将所有药材样品分为四类，即在1 615 cm-1处有吸收峰的药材为一类，在1 646 cm-1处有吸收峰的药材为一类，1 646和1 615 cm-1处均有吸收峰的药材S1为一类，在2 962 cm-1处有吸收的药材S5为一类；当欧式距离为20时，可将药材分为S5和其他药材两大类。双指标序列法结果显示，S9:S14，S2:S10，S3:S8和S12:S13序列共有峰率为100%，罗布麻药材样品总体共有峰率≥61.1%，变异峰率≤53.8%，认为未表现出明显的产地差异性。红外光谱相关系数分析、聚类分析和双指标序列分析结果相互补充和印证，说明该方法可靠有效，可从不同角度分析评价罗布麻药材产地差异，为保证药材质量的稳定可控提供参考。

Study on Infrared Spectrum Fingerprint of Apocynumvenetum L. in Xinjiang Based on Double Index Analysis

Apocynum venetum L. was a commonly used medicinal material in Xinjiang, mainly used for hepatic yang vertigo, palpitation and insomnia, oedema and oliourine, and it also had a good therapeutic effect on hypertension and depression. In order to ensure safety and stability of clinical medication, four traditional identification methods and modern chromatographic and spectral techniques were commonly used to identify the quality differences of Chinese medicinal materials. In this study, 17 batches of A. venetum collected from different regions in Xinjiang were analyzed by Fourier transform infrared spectroscopy (FTIR ). The range of infrared spectrum was 4 000~400 cm-1, the range of secondary derivative spectra was 1 800~600 cm-1. After obtaining these fingerprints, the correlation coefficients were calculated by using the fingerprint spectrum (1 800~400 cm-1) with dense spectral bands. Then, the infrared fingerprints of A. venetum from different habitats were classified and compared by combining the infrared spectral absorption peak system clustering, the common peak rate and the variation peak rate double index sequence analysis. The results showed that the infrared spectra of A. venetum from different regions in Xinjiang were similar in shape and position of peaks, and all of them had absorption in wavenumber of 3 336, 2 920, 1 443, 1 375, 1 247, 1 103, 1 070, 833 and 601 cm-1. There were characteristic and strong peaks at 1 103, 1 070 and 1 656~1 609 cm-1. And the CO2-₃ vibration peaks in 892 and 717 cm-1 only appeared in S4 from Karamay Dushanzi Districtand S5 in Wusu Ganjiahu nature reserve, which was related to the high degree of soil salinization. Except S5, the correlation coefficient of the other 16 batches of medicinal materials was higher than 0.960, indicating that A. venetum from different origins had a certain similarities. It was found that the peaks of the second derivative spectra were similar, but the number of peaks increases obviously in the range of 1 444~1 738 and 833~1 030 cm-1. SPSS 21.0 software was used to conduct cluster analysis with the absorption wave number of each medicinal material as the variable. S9 and S14, S2 and S10, S3 and S8, S12 and S13 were first clustered into one class; when the Euclidean distance was 15, the medicinal materials were divided into four categories: the medicinal materials with absorption peaks at 1 615 cm-1, the medicinal materials with absorption peaks at 1 646 cm-1, S1 with absorption peaks at 1 646 and 1 615 cm-1, and only S5 with absorption peaks at 2 962 cm-1 in all materials. When the European distance was 20, the medicinal materials were divided into S5 and other medicinal materials. The results of the double index sequence method showed that the common peak ratios of S9:S14, S2:S10, S3:S8 and S12:S13 were 100%, and the common peak ratios of A. venetum were ≥61.1%, and the variation peak ratios were ≤53.8%, it was considered that there was no obvious origin difference. The results of correlation coefficient analysis, cluster analysis and double index sequence analysis was complementary and verified, it indicated that these methods were reliable and effective, which can analyze and evaluate the A. venetum samples from different perspectives to provide a reference for ensuring the stability and controllability of medicinal materials.