Establishment of HPLC fingerprint of Rehmanniae Radix and its HPLC-ESI-MS analysis / 中草药

ABSTRACT

Objective: To establish a quality assessment method for Rehmanniae Radix based on HPLC fingerprint and qualitatively analyze the chemical constituents by HPLC-ESI-MS. Methods: The methanol extract of Rehmanniae Radix by ultrasonication was separated on an Agilent Extend C18 column (250 mm × 4.6 mm, 5 μm) with gradient elution. The mobile phase consisted of acetonitrile-0.1% phosphoric acid. The detection wavelength was 215 nm. The similarity evaluation of 15 batches of Rehmanniae Radix from different sources was carried out by the "Similarity Evaluation System for Chromatographic Fingerprints of TCM" (Chinese Pharmacopoeia Commission, version 2004A). Ultra high-performance liquid chromatography coupled with linear ion trap-Orbitrap mass spectrometer (UPLC-LTQ-Orbitrap MS) was used to characterize the chemical constituents of the methanol extract of Rehmanniae Radix. Results: The chromatographic fingerprints of 15 batches of Rehmanniae Radix were generated with 10 common peaks. The similarity scores between each material batch and the reference fingerprint ranged from 0.910-0.982. A total of 67 components were putatively identified along with six unknown components via referring to reference components and literatures and analyzing MS/MS data. Conclusion: The established method of fingerprint is specific and can be a reliable method used for quality assessment of Rehmanniae Radix.