Abstract: HPLC fingerprint of different processed products of Rehmannia glutinosa （fresh Rehmannia glutinosa, Rehmannia glutinosa tablets, raw Rehmannia glutinosa, and cooked Rehmannia glutinosa） was established and the content of 11 indicator components was determined. 11 common peaks were identified, and principal component analysis （PCA） and cluster analysis （HCA） were combined to analyze the trend of chemical composition changes during the processing, laying a foundation for the quality evaluation and pharmacologica research of different processed products of Rehmannia glutinosa. The results showed that the method of combining HPLC fingerprint with multi indicator component content determination was suitable for the HPLC fingerprint analysis of different processed products of Rehmannia glutinosa. PCA and HCA results showed that cooked Rehmannia glutinosa was significantly different from fresh Rehmannia glutinosa, Rehmannia glutinosa tablets, and raw Rehmannia glutinosa. Fresh Rehmannia glutinosa and Rehmannia glutinosa tablets were classified into two categories in PCA, while fresh Rehmannia glutinosa and Rehmannia glutinosa tablets were clustered into one category in HCA; the linear relationship between the 11 indicator components was good, with R²≥0.999 5. The variation trends of the content of the 11 indicator components were different. The method of combining HPLC fingerprint with multi indicator component content determination reflected the chemical composition changes during the processing of Rehmannia glutinosa, which was suitable for quality evaluation of Rehmannia glutinosa at different stages of processing, laying a research foundation for pharmacological and pharmacological research and the discovery of quality markers.

Key words: Rehmannia glutinosa Libosch., processing, HPLC, fingerprint, content determination, pattern recognition