We aimed to establish a quantitative analysis method of six constituents (5-caffeoylquinic acid, 3-caffeoylquinic acid, 4-caffeoylquinic acid, 1,3-dicaffeoylquinic acid, 3,4-dicaffeoylquinic acid, and 4,5-dicaffeoylquinic acid) in Artemisia capillaris (Yinchen) and its decoction by using HPLC coupled with DAD. Besides, the transformation paths of the six constituents were analyzed in decoction preparation processing. The analytical method was fully validated in terms of linearity, sensitivity, precision, repeatability, and recovery and applied to assess the transformation trend and quantitative analysis of the six constituents in Yinchen decoction. The contents of six constituents varied greatly in Yinchen herb and Yinchen decoction, and there were inextricable internal relationships between them. Presumably 3-caffeoylquinic acid was isomerized to generate 5-caffeoylquinic acid and 4-caffeoylquinic acid. Similarly, 1,3-dicaffeoylquinic acid and 3,4-dicaffeoylquinic acid were produced by isomerization of 4,5-dicaffeoylquinic acid. In conclusion, this study provides a chemical basis for quality control of Yinchen decoction, and the changes of selected markers in decoction could give us some novel perspectives to study the relationship between substances and drug efficacy.

中文翻译：

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HPLC-DAD定量分析茵陈中六种酚酸及其在煎剂制备过程中的转化途径。

我们旨在建立一种定量分析六种成分（5-咖啡酰奎尼酸，3-咖啡酰奎尼酸，4-咖啡酰奎尼酸，1,3-二咖啡酰奎尼酸，3,4-二咖啡酰奎尼酸和4,5-二咖啡酰奎尼酸）的定量分析方法。毛蒿（Yinchen）及其水煎液，采用HPLC与DAD联用。此外，还对汤剂制备过程中六种成分的转化路径进行了分析。该分析方法在线性，灵敏度，精密度，重复性和回收率方面均得到充分验证，并用于评估银尘汤中六种成分的转化趋势和定量分析。银chen药草和银chen汤中六种成分的含量差异很大，两者之间有着千丝万缕的内在联系。大概3-咖啡酰基奎宁酸被异构化以产生5-咖啡酰基奎宁酸和4-咖啡酰基奎宁酸。类似地，通过4，5-二咖啡酰基奎宁酸的异构化来制备1，3-二咖啡酰基奎宁酸和3，4-二咖啡酰基奎宁酸。结论，