ABSTRACT
OBJECTIVE：To compare the che mical composition differences of raw and fried processed Glycyrrhiza uralensis ， and provide reference for clarifying the regularity of chemical composition change before and after processing and material basis of differential use of raw and fried G. uralensis . METHODS ：UPLC-Q-TOF-MS technology was used to detect the composition of raw and fried G. uralensis . By comparing the retention time ，relative molecular weight and other information of the compounds with the databases such as METLIN ，Agilent MassHunter PCDL Manager off-line component identification workstation and references ，the chemical compositions of the compounds were preliminarily identified. Principal component analysis （PCA）method was used to observe the overall distribution trend of samples. Orthogonal partial least square （OPLS-DA）method was used to screen differential compounds [VIP ＞1.0 and | P（corr）|≥0.5 as criteria] and analyze the content changes of differential compounds. RESULTS ：A total of 31 common compounds were preliminarily identified from the raw and fried G. uralensis . PCA analysis showed that raw and fried G. uralensis could be separated well. OPLS-DA analysis result showed that 15 characteristic differential compounds were screened out from raw and fried G. uralensis ，including 13 flavonoids and 2 coumarins；the contents of 8 flavonoids compounds such as licoflavone A ，glycyrrhizin and glabridin and so on in G. uralensis were significantly increased （P＜0.05 or P＜0.01）， while the contents of 5 flavonoids components such as glycyrrhizinol ，glycyrin A and 2 coumarins components such as 2′-4′-trihydroxy-5-methoxy-3-coumarim and hedysarimcoumestan B were significantly decreased （P＜0.05） after honey-fried processing. CONCLUSIONS ：Before and after processing ，there are obvious differences between some flavonoids and coumarins ， which may be the main material basis for differential use of raw and honey-fried G. uralensis .