Discrimination of three medicinal materials from the Citrus genus by HPLC fingerprint coupled with two complementary software.

Introduction: Pericarpium Citri Reticulatae, Pericarpium Citri Reticulatae Viride and Fructus Aurantii come from the fruit of Citrus genus and possess analogous pharmacological activities. Either two or three of them are often present in one preparation. However, there is no standard method to differentiate the three herbal medicines for quality control.

Objective: To develop a fingerprint method for authentication of these three herbal medicines by HPLC.

Methodology: Methanol extracts were analysed by HPLC, with a mobile phase of 0.1% phosphoric acid in water (A) and acetonitrile (B) in a gradient programme. The flow rate was set at 0.8 mL/min and UV detection at 320 nm. Principal component analysis and similarity evaluation were employed to analyse the chromatographic dataset.

Results: The chromatograms of 20 Pericarpium Citri Reticulatae, 13 Pericarpium Citri Reticulatae Viride and 15 Fructus Aurantii samples from diverse habitats had 13 peaks in common, and showed one peak characteristic for Pericarpium Citri Reticulatae Viride and two peaks characteristic for Fructus Aurantii. Furthermore, it was possible to differentiate the three medicines by a 'fingerprint region'. The difference between Pericarpium Citri Reticulatae and Fructus Aurantii was much bigger than that between Pericarpium Citri Reticulatae and Pericarpium Citri Reticulatae Viride, as could be shown by calculation of common peak ratio and variation peak ratio.

Conclusion: A reliable HPLC fingerprint method coupled with principal component analysis and similarity evaluation was developed and showed substantial differentiation power for the three medicines.