基于UHPLC-Q-Orbitrap HRMS和HPLC-DAD法研究不同干燥方式对马蓝叶化学成分的影响

目的 研究阴干、晒干、真空冷冻干燥、热风干燥4种干燥方式对马蓝Baphicacanthus cusia叶化学成分的影响，寻找差异成分，并建立HPLC-DAD同时定量分析5种吲哚类生物碱成分的方法，以期为建立规范的马蓝叶干燥方式提供理论依据。方法 利用UHPLC-Q-Orbitrap HRMS对4种干燥处理的马蓝叶进行定性分析，并结合热图聚类分析（heat map clustering analysis，HCA）、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）筛选差异成分。结果 共鉴定出67个共有化合物。HCA和PCA将阴干和热风干燥归为一类。OPLS-DA筛选出14个差异成分，多为生物碱类，且呈现出不同的变化规律。HPLC-DAD结果表明，不同干燥方式马蓝叶中的5种吲哚类生物碱含量存在明显差异。其中，热风干燥样品的靛蓝含量最高，靛玉红含量最低；阴干样品的靛红、色胺酮、靛玉红含量最高。结论 不同的干燥方式对马蓝叶的品质有明显影响。热风干燥和晒干有利于吲哚苷水解合成靛蓝，但靛红和靛玉红的含量较低。而阴干和真空冷冻干燥样品的靛蓝含量较低，而靛玉红含量较高。阴干和热风干燥能显著提高马蓝叶药效成分的总含量。建议在初加工马蓝叶时使用阴干或热风干燥，为进一步探究马蓝叶的产地加工方式提供了数据支持，同时也为评估马蓝叶的质量提供了技术支持。

Effects of different drying methods on chemical composition of Baphicacanthus cusia leaves based on UHPLC-Q-Orbitrap HRMS and HPLC-DAD methods

Objective The effects of four drying methods by drying in the shade, sun drying, vacuum freeze-drying, and hot air drying on the chemical components of Malan (Baphicacanthus cusia) leaves were studied to searched for the differential compounds, and a method for simultaneous quantitative analysis of five indole alkaloids was established by HPLC-DAD, in order to provide theoretical basis for establishing standardized drying methods of B. cusia leaves. Methods UHPLC-Q-Orbitrap HRMS was used to qualitatively analyze the B. cusia leaves with four drying methods, and heat map clustering analysis (HCA), principal component analysis (PCA) and orthogonal partial least square-discriminant analysis (OPLS-DA) were used to screen the differential compounds. Results A total of 67 common compounds were identified. Heat map clustering analysis (HCA) and PCA analysis classified the drying in the shade and the hot air drying in one class. OPLS-DA screened 14 differential components, most of which were alkaloids, and showed different change rules. The results of HPLC-DAD showed that the contents of five indole alkaloids in B. cusia leaves were significantly different by different drying methods. Among them, the hot-air drying samples had the highest indigo content and the lowest indirubin content. The drying in the shade samples had the highest content of isatin, tryptanthrin and indirubin. Conclusion Different drying methods have a significant impact on the quality of B. cusia leaves. Hot air drying and sun drying favor the hydrolysis of indican to synthesize indigo, but the content of isatin and indirubin is lower. Drying in the shade and vacuum freeze-dried samples had a lower indigo content, while indirubin a higher content. Drying in the shade and hot air drying significantly increased the total content of the B. cusia leaves efficacy components. It is suggested to use drying in the shade and hot air drying in the initial processing of the B. cusia leaves, which provides data support for further study of the processing methods of the B. cusia leaves, and also provide technical support for evaluating the quality of the B. cusia leaves.