Determination Of Paeoniflorin And Albiflorin And Metabolism Of Paeoniflorin And Total Paeony Glycosides In Rats

Paeoniflorin and the albiflorin were determined in Radix Paeoniae Rubra. High-performance liquid chromatography coupled with photodiode array detection and evaporative light scattering detection (HPLC-DAD-ELSD) was established to determine paeoniflorin and albiflorin simultaneously in Radix Paeoniae Rubra from 9 different sources. The assay was performed on a DiamonsilTM C19 (4.6 mm×250 mm, 5 μm) column by a gradient elution program with acetonitrile and aqueous formic acid (0.05% v/v) as mobile phase at a flow rate of 1.0 mL/min. The detection wavelength of DAD was 230 nm and the evaporator tube temperature of ELSD was set at 110℃ with the nebulizing gas flow rate of 3 L/min. The temperature of column was kept at 30 ℃. The linear ranges of paeoniflorin and albiflorin were within 0.050-1.510 mg/mL and 1.007～5.035 mg/mL. The recoveries of paeoniflorin and albiflorin were 96.2%～102.9% and 95.0%～102.4%, respectively, while the RSD of them were 0.2%～2.5%. This method was quick, simple, accurate and specific. It could be used for the quality control of Radix Paeoniae Rubra. The proposed approach was expected as a powerful tool for the quality control of Radix Paeoniae Rubra.LC-MS technique was used to investigate the metabolism in rats of paeoniflorin. Rats were gived of total glucosides of peaony and paeoniflorin to for intragastric administration, and then samples of plasma, urine and faeces were collected, respectively. A simple, sensitive and specific high performance liquid chromatography/Fourier transform ion cyclotron resonance mass spectrometer method(HPLC-FT-ICR)has been developed for the mass spectrometry detection of these samples. The samples were contained the blank drug administration group, the reference substance of paeoniflorin and total glucosides of peaony, and the plasma, urine and faeces of paeoniflorin and total glucosides of peaony. We got the exact molecular weight and retention time of possible metabolites. A high performance liquid chromatography/quadrupole tandem time-of-flight mass spectrometry (HPLC-Q-TOF MS) method was established for rapid global quality evaluation of possible metabolites. We got 45 metabolites from metabolites of paeoniflorin, which contain 9 identified metabolites,2 new metabolites, and 34 undetermined compounds. We found 11 metabolites in plasma, which contain 1 identified metabolites. We found 17 metabolites in urine, which contain 5 identified metabolites,1 new metabolites. We found 18 metabolites in feces, which contain 4 identified metabolites,1 new metabolites. Identified compounds include phenol glucuronide, paeonimetabolin Ⅰ glucuronide isomer Ⅰ, paeonimetabolin Ⅰ glucuronide isomer Ⅱ, C10H14O3 sulfate, O-paeonimetabolin Ⅱ glucoside, C10H14O3 glucuronide, C8H8O3 glucuronide and 4-O-methyldesbenzoylpaeoniflorin. TPG metabolites had the same 38 metabolites compared with paeoniflorin monomer administration, and there were 7 compounds not among in TPG metabolites. Paeoniflorin metabolic reactions in the body were mainly oxidation, reduction, hydrolysis, and open-loop binding reactions. Metabolites were mainly combination of sulfuric acid and glucuronide in urine and faeces. TPG metabolites were varied from monomer paeoniflorin administration, and it might be that the monomers had mutual influence in the metabolism. The results possibly provided a reference for clinical applications and security and metabolic mechanism of TPG.