基于UPLC特征图谱结合多模式识别和色度值的槐角炮制前后差异研究

目的 测定槐角炮制前后的超高效液相色谱（UPLC）特征图谱和色度值，结合不同模式识别方法比较槐角炮制前后的差异性，为槐角和蜜槐角的质量控制及评价提供参考。方法 采用UPLC法对槐角炮制前后样品进行测定，按《中药色谱指纹图谱相似度评价系统（2012版）》对色谱图进行匹配生成槐角炮制前后的UPLC特征图谱，并对炮制前后的色度值（L、a、b）进行测定，通过相似度分析、对照品比对、方差分析、聚类分析、主成分分析（principal component analysis，PCA）和正交偏最小二乘判别分析（orthogonal partial least squares discriminant analysis，OPLS-DA）对槐角炮制前后进行多模式识别研究。结果 建立了槐角炮制前后的UPLC特征图谱，槐角和蜜槐角分别确定了23、24个共有峰，指认2、15、16、20、21号峰为没食子酸、芦丁、染料木苷、槲皮苷、槐角苷，炮制后新增成分24号峰为5-羟甲基糠醛；相似度分析结果显示槐角炮制前后相似度均大于0.98，聚类分析结果显示槐角炮制前后区分不明显，PCA可以将槐角和蜜槐角大致分为2类，OPLS-DA分析可将槐角和蜜槐角明显区分为2类，且结果显示1、2、10、22、23、24号峰是引起槐角和蜜槐角间成分差异的主要标志性成分，与方差分析结果一致；色度值ΔE范围为5~13，炮制前后色差可被肉眼识别。结论 建立的多指标特征图谱和色度值鉴别方法对槐角药材及其炮制品的质量控制及整体性评价具有重要意义。

Comparative study on UPLC characteristic chromatogram combined with multiple chemical pattern recognition and chromatic value of Sophorae Fructus and its processed products

Objective To determine Ultra Performance Liquid Chromatography (UPLC) characteristic chromatogram and chromatic value of Sophorae Fructus and its processed products, and to compare their difference according to multiple chemical pattern recognition method, and to provide reference for quality control and evaluation of Huaijiao (Sophorae Fructus) and its processed products. Methods Sophorae Fructus and its processed products were determined by UPLC. According to the TCM Chromatographic Fingerprint Similarity Evaluation System (2012 edition), the chromatograms were matched to generate the UPLC characteristic chromatogram of Sophorae Fructus and its processed products, and the chromatic value (L, a, b) before and after fried with honey was determined. The chromatograms of Sophorae Fructus and its processed products were analyzed according to multiple chemical pattern recognition by variance analysis, cluster analysis, principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA). Results UPLC characteristic chromatogram of Sophorae Fructus and its processed products were established respectively, and 23 common peaks were confirmed for Sophorae Fructus; 24 common peaks were confirmed for Sophorae Fructus stir-fried with honey. No. 2, 15, 16, 20, 21 peaks were identified as gallic acid, rutin, genistin, quercitrin and sophoricoside respectively, and the new component No. 24 peaks were identified as 5-hydroxymethylfurfural after fried with honey. The results of similarity analysis showed that the similarity of Sophorae Fructus and its processed products was greater than 0.98. Cluster analysis showed that there were only a small part of distinctions of Sophorae Fructus and its processed products, and PCA can roughly divide Sophorae Fructus and its processed products into two categories respectively. PLS-DA can distinguish Sophorae Fructus and its processed obviously, and showed that No. 1, 2, 10, 22, 23, and 24 peaks were the main marker components that caused the differences of chemical components of Sophorae Fructus and its processed products, which is consistent with the results of variance analysis. The ΔE range of chromatic value was 5-13, and the color difference of Sophorae Fructus and its processed products can be recognized by the naked eye. Conclusions The characteristic chromatogram of multiple indicators and chromatic value identification method established in this study has vital significance for to the quality control and overall evaluation of Sophorae Fructus and its processed products.