地黄药材的红外指纹图谱及多元统计分析

中药产地是影响药材质量的重要因素，不同产地生长环境对中药的生长及代谢产物的累积具有直接影响，中药材素有道地产区分为非道地产区，在我国具有悠远历史，由于其产地的变迁以及现代主产地的增加，导致当今药材主产地与历史记录略有出入。傅里叶变换红外光谱技术具有快速无损的优点，红外光谱可完整地将不同产地地黄的信息表达，结合化学计量学将红外光谱所体现的信息数字化。该工作运用傅里叶变换红外光谱仪采集不同产地地黄红外光谱，对原始光谱进行基线校正、平滑点数6个、选取900~1 200 cm-1波段进行最高峰归一化等预处理，对每个产地红外光谱各主要特征峰的相对峰强度进行计算，采用正态分布、聚类(CA)和主成分分析(PCA)比较其质量差异，地黄的产地鉴别对中药的合理应用具有科学意义。结果表明采用傅里叶变换红外光谱法采集73批不同产地生地黄的红外图谱，73批不同产地地黄红外光谱指纹图谱峰形、峰位、峰高基本相似，不同产地地黄中含有相同的化学成分，其特征峰、形状基本一致，其中河南产地的地黄有个别特征峰的高度突出，指纹区存在一定差异，差异主要贡献波段为：1 639，1 424，1 354和1 260 cm-1，共标定13个共有峰。聚类分析可将73批地黄样品分为河南产的怀地黄和其他地黄两类，表明不同产地地黄存在内部质量差异；正态分布与聚类分析结果一致，在1 639 cm-1处，河南产的怀地黄与其他省份的正态分布曲线交叉依次为：山东省＞山西省＞河北省，此方法能有效将道地药材与非道地药材区分开；对所得的共有峰相对峰强度进行降维处理，并计算不同产地地黄的主成分综合得分，结果显示河南产怀地黄得到综合得分均高于其他产地的地黄，表明河南产的怀地黄质量最佳。傅里叶变换红外光谱结合多元统计分析方法可以无损、有效、快速的鉴别不同产地地黄。

Infrared Fingerprint and Multivariate Statistical Analysis of Rehmannia Glutinosa

The place of origin of Chinese medicine is an important factor affecting the quality of medicinal materials. The growth environment of different places of production directly impacts the growth of Chinese medicine and the accumulation of metabolites. Chinese medicinal materials are known for the difference between authentic and non-dao regions, and they have a long history in China. The change of its production area and the increase of modern main production areas have resulted in slight discrepancies between the main production areas of current medicinal materials and historical records. Fourier transform infrared spectroscopy technology has the advantages of being fast and non-destructive. Fourier Transform Infrared spectroscopy is characterized for its high speed and non-destruction. Infrared spectroscopy can completely express the information on different origins of Rehmannia glutinosa. Combined with chemometrics, FTIS can also express the digitization of information embodied in infrared spectroscopy. It can collect different Infrared spectroscopy of Rehmannia glutinosa by using Fourier transform infrared spectrometer. The original spectral data can be preprocessed like baseline correction of the original spectrum, 6 smoothing points, selection of 900~1 200 cm-1 band for highest peak normalization and so on. Moreover, FTIS can calculate the relative peak height of the main characteristic peaks of the infrared spectrum of each origin. FTIS is trying to put up quality differences with normal distribution, clustering (CA) and principal component analysis (PCA). In addition, the identification of the origin of Rehmannia glutinosa has scientific significance for the rational application of Chinese medicine. The results showed that the infrared spectra of 73 batches of Rehmannia glutinosa from different origins were collected by Fourier transform infrared spectroscopy. The peak shape, peak position and height of the fingerprints of 73 batches of Rehmannia glutinosa from different origins were basically similar, and the same chemical components were contained in different origins. The characteristic peaks and shapes are basically the same. Rehmannia glutinosa produced in Henan has prominent heights of individual characteristic peaks, and there are certain differences in fingerprint areas. The main contribution bands for the differences are: 1 639, 1 424, 1 354 and 1 260 cm-1. Four bands, a total of 13 common peaks are calibrated. Cluster analysis can divide 73 batches of Rehmannia glutinosa samples into two types, namely Huai Rehmannia glutinosa produced in Henan and other Rehmannia glutinosa, which indicates that there are internal quality differences in different origins of Rehmannia glutinosa. The normal distribution is consistent with the cluster analysis results. It showed that at the peak of 1 639 cm-1, the normal distribution curves of Huai Rehmannia glutinosa produced in Henan and other provinces are in order as follows: Shandong, Shanxi, Hebei. Therefore, this method can distinguish authentic medicinal materials from non-authentic medicinal materials well. It can reduce the dimension of the relative peak height of the resulting common peaks. And it can calculate the principal component composite scores of different origins of Rehmannia glutinosa. The results showed that the comprehensive scores of Rehmannia glutinosa produced in Henan were higher than those of other origins, indicating that the quality of Rehmannia glutinosa produced in Henan was the best. Fourier transform infrared spectroscopy combined with multivariate statistical analysis methods can non-destructively, effectively and quickly identify different origins of Rehmannia glutinosa.