Study on quality evaluation of fresh Leonurus japonicus Houtt.based on fingerprint and component determination of leonurine hydrochloride and stachydrine hydrochloride
Objective To establish a method for the determination of the index components and fingerprint of fresh Leonurus japonicus,and to comprehensively evaluate the overall quality of fresh L.japonicus from different origins and different harvest dates in combination with the drug safety index.Method A total of 23 batches of fresh L.japonicus in different regions were collected,the fingerprints,stachydrine hydrochloride content,5 kinds of leonurine hydrochloride content,heavy metals and harmful elements content and 33 prohibited pesticide residues of each batch were determined,and the data of each index component were analyzed by chemical pattern recognition such as principal component analysis(PCA),hierarchical cluster analysis(HCA),orthogonal partial least squares discriminant analysis(OPLS-DA)and entropy weight TOPSIS method,at the same time,fresh L.japonicus from three regions at different harvest times were collected,and determined the fingerprints,stachydrine hydrochloride content and leonurine hydrochloride content,and analyzed the changes of chemical components of fresh L.japonicus.Result The established fingerprint spectrum of fresh L.japonicus was calibrated with 15 peaks,and 6 peaks were identified,which were peak 2(neochlorogenic acid),peak 4(chlorogenic acid),peak 8(leonurus hydrochloride),peak 12(rutin),peak 13(isoquercetin),and peak 15(tiliroside).There were some differences in fingerprints and content of index components of different batches of fresh L.japonicus,the similarity between the 23 batches of fresh L.japonicus and the control characteristic chromatography was greater than 0.9,the fluctuation range of leonurine hydrochloride content was 0.17 to 0.78 mg·g-1,and the fluctuation range of stachydrine hydrochloride content was 0.71 to 5.82 mg·g-1,the contents of lead,cadmium,arsenic,mercury and copper met the general limit requirements for heavy metals and harmful elements in the Pharmacopoeia,and 33 prohibited pesticide residues were not detected.PCA and HCA could aggregate 23 batches of fresh L.japonicus into three categories,and the harvest time had a great impact on the overall quality of fresh L.japonicus,OPLS-DA screened out that the content of leonurine hydrochloride and the peak areas of peaks 1,5,7,and 8 the main factors affecting the quality of fresh L.japonicus.The entropy weight TOPSIS method showed that the quality of fresh L.japonicus at seedling stage was better,the content of leonurine hydrochloride stachydrine hydrochloride and the peak areas of peak 2-5,peak 10-12 and peak 14 of fresh L.japonicus at different harvest times showed a downward trend,the peak areas of peak 6,7,9,13 and 15 first increased and then decreased,and the peak area of peak 1 showed a fluctuating trend.Conclusion The method of establishing the fingerprint and content determination method of fresh L.japonicus was highly precise,reproducible and the results were stable and reliable,the results of comprehensive quality evaluation and the variation of chemical composition in different harvest periods can provide a reference for the comprehensive evaluation and control of the quality of fresh L.japonicus.