Quality evaluation of isatis root based on fingerprint chromatography and chemometrics
Objective:To establish an HPLC fingerprint for Isatis root(Radix Isatidis),determine the content of(R,S)-goitrin,uridine,guanosine,and adenosine in it,and analyze the quality of Isatis root samples by combining with che-mometrics to provide a basis for its quality control.Methods:An HPLC fingerprint and content determination method were established.Column:Agilent ZORBAX SB-C18(250 mm×4.6 mm,5 µm).Mobile phase:water(A)-methanol(B)for gradient elution in a flow rate of 0.8 ml/min.Column temperature:30℃.Determine wavelength:254 nm.Injec-tion volume:10µl.Similarity evaluation,hierarchical cluster analysis(HCA),principal component analysis(PCA)and orthogonal partial least squares discriminant analysis(OPLS-DA)were used to analyze Isatis root samples from differ-ent regions.Correlation analysis was conducted by Pearson correlation analysis on the content of the 4 components,which are(R,S)-goitrin,uridine,guanosine,and adenosine.Results:The established fingerprint is with a similarity of 0.924~1.000 and 18 common peaks marked,confirming the 4 components,which are(R,S)-goitrin,uridine,guanosine,and adenosine.Correlations were found among the contents of these 4 components.In 36 batches of samples,the con-tent ranges were as follows:(R,S)-goitrin,0.148 9%~0.562 5%;uridine,0.035 2%~0.260 1%;guanosine,0.015 0%~0.240 5%;adenosine,0.008 0%~0.080 2%.HCA clustered the 36 batches of sampels into 4 categories,which closely related to their geographic origins.PCA extracted four principal components,with a cumulative contribution rate of 82.649%.OPLS-DA identified 5 components with significant contributions.Conclusion:The fingerprint analysis method established in this study carries high reliability,and the methodological validation meets the required stan-dards.The combination of fingerprint chromatography and chemometric analysis accurately reflects the quality differ-ences in Isatis root samples,providing a reference for further research on its quality control.