Qualitative and quantitative evaluation of Flos Puerariae by using chemical fingerprint in combination with chemometrics method

Abstract In order to better control the quality of Flos Puerariae (FP), the qualitative and quantitative analysis were initially performed by using chemical fingerprint and chemometrics methods in this study. Firstly, the fingerprint of FP was developed by HPLC and the chemical markers were screened out by similarity analysis (SA), hierarchical clustering analysis (HCA), principal components analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA). Next, the chemical constituents in FP were profiled and identified by HPLC coupled to Fourier transform ion cyclotron resonance mass spectrometer (HPLC-FT-ICR MS). Then, the characteristic constituents in FP were quantitatively analyzed by HPLC. As a result, 31 common peaks were assigned in the fingerprint and 6 of them were considered as qualitative markers. A total of 35 chemical constituents were detected by HPLC-FT-ICR MS and 16 of them were unambiguously identified by comparing retention times, UV absorption wavelength, accurate mass and MS/MS data with reference substances. Subsequently, the contents of glycitin, genistin, tectoridin, glycitein, genistein and tectorigenin in 13 batches of FP were detected, ranging from 0.4438 mg/g to 11.06 mg/g, 0.955 mg/g to 1.726 mg/g, 9.81 mg/g to 57.22 mg/g, 3.349 mg/g to 41.60 mg/g, 0.3576 mg/g to 0.989 mg/g and 2.126 mg/g to 9.99 mg/g, respectively. In conclusion, fingerprint analysis in combination with chemometrics methods could discover chemical markers for improving the quality control standard of FP. It is expected that the strategy applied in this study will be valuable for further quality control of other traditional Chinese medicines (TCMs).