LC-MS/MS analysis and pharmacokinetic study on five bioactive constituents of Tanreqing injection in rats / 中国天然药物

Tanreqing injection (TRQ), a well-known traditional Chinese medicine formula, is commonly used to treat respiratory diseases. In the present study, a rapid, selective, and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated to simultaneously determinate the plasma contents of 5 major constituents of TRQ, including chlorogenic acid (CHA), caffeic acid (CFA), baicalin (BA), ursodeoxycholic acid (UDCA) and chenodeoxycholic acid (CDCA) in rats after intravenous administration of TRQ. Chromatographic separation was performed on an Agilent Zorbax SB-C column (3.5 μm, 100 mm × 2.1 mm), with acetonitrile and 0.1% aqueous formic acid as mobile phase at a flow rate of 0.3 mL·min. The calibration curves were linear over the ranges of 27.0-13 333.0 ng·mL for CFA, 30.0-14 933.0 ng·mL for CHA, 50.0-50 333.0 ng·mL for BA, 550.0-55 000.0 ng·mL for UDCA, and 480.0-48 000.0 ng·mL for CDCA, respectively. Intra- and inter-day precisions (relative standard deviations, RSDs) were from 3.11% to 14.08%. The extraction recoveries were greater than 71% and accuracy (relative recovery) was from 89% to 137% for all analytes, except endogenous bile acids. This validated method was successfully applied to the first pharmacokinetic study of CFA, CHA, BA, UDCA and CDCA in rat plasma after intravenous administration of TRQ.

Metabolite profiling of Zi-Shen pill in rat biological specimens by UPLC-Q-TOF/MS / 中国天然药物

This study aimed to profile the chemical constituents of Zi-Shen pill (ZSP) and its metabolites in plasma, urine, and prostate tissue, after administration into rats. Based on the chromatographic retention behavior, fragmentation patterns of chemical components, published literatures, and literature databases, an UPLC-Q-TOF/MS (LC-TOF/MS) method was established to identify the components of ZSP and its metabolites in biological samples. A total of 101 compounds were identified and tentatively characterized from the ZSP, including alkaloids, xanthones, and timosaponins. Except for 33 prototype components, 22 metabolites were detected in the plasma, urine, and prostate, and mainly came from Phellodendri Amurensis Cortex and Anemarrhenae Rhizoma. It was found that glucuronidation and sulfation were the major metabolic processes of xanthones, while oxidation, demethylation, and glucuronidation were the major metabolic pathways of alkaloids. In summary, the present study provided important chemical information on the metabolism of ZSP, indicating that alkaloids might be able to be absorbed into the prostate. The results provided a basis for further studies of the mechanisms of action for ZSP.

An HPLC-MS/MS method for the quantitative determination of platycodin D in rat plasma and its application to the pharmacokinetics of Platycodi Radix extract / 中国天然药物

AIMS@#To develop an HPLC-MS/MS method for the quantification of platycodin D (PD) in rat plasma, and to acquire the main pharmacokinetic parameters of PD after oral administration of pure PD or of Platycodi Radix extract (PRE) containing PD.@*METHOD@#Plasma samples were pretreated with solid-phase extraction using an Oasis® HLB SPE cartridge. Madecassoside was used as the internal standard (IS). Chromatographic separation was achieved on an ODS column (100 mm × 2.1 mm i.d., 3.5 μm) with a mobile phase consisting of acetonitrile/water (30 : 70, V/V) containing 0.1 mmol·L(-1) ammonium acetate at a flow rate of 0.25 mL·min(-1). The detection was performed on a triple quadruple tandem mass spectrometer using an electrospray ionization (ESI) source with a chromatographic run time of 3.0 min. The detection was operated by multiple reaction monitoring (MRM) of the transitions of m/z 1 223.6→469.2 for PD and of m/z 973.6→469.2 for madecassoside (IS), respectively.@*RESULTS@#The calibration curve was linear from 5 to 2 000 ng·mL(-1) (r(2) >0.99) with a lower limit of quantification (LLOQ) of 5 ng·mL(-1). The intra- and inter-day precision (relative standard deviation, RSD) values were below 15% and the accuracy (relative error, RE) was from -15% to +15% at three quality control (QC) levels. Plasma concentrations of PD were determined for 24 h after i.v. administration of PD, and oral administration of PD and PRE, respectively. The absolute oral bioavailability of PD in rats was found to be (0.48 ± 0.19)% when administered PD, and to be (1.81 ± 0.89)% when administered PRE.@*CONCLUSION@#The developed HPLC-MS/MS method was successfully applied to assess the pharmacokinetic parameters and oral bioavailability of PD in rats after administration of PD and Platycodi Radix extract.

Fingerprint analysis of Zhimu-Huangbai herb pair and simultaneous determination of its alkaloids, xanthone glycosides and steroidal saponins by HPLC-DAD-ELSD / 中国天然药物

AIM@#To develop and validate a high performance liquid chromatography (HPLC) coupled with diode array and evaporative light scattering detectors (DAD-ELSD) method for the quantitative determination and fingerprint analysis of ten active constituents in three chemical classes (namely, xanthone glycosides, steroidal saponins, and alkaloids) in Zhimu-Huangbai herb pair (ZB).@*METHOD@#Chromatographic separation was performed on a Diamonsil C18 column (4.6 mm × 250 mm, 5 μm, Dikma) by gradient elution using acetic acid in acetonitrile solution at a flow rate of 1.0 mL·min(-1) at 260 nm. The drift tube temperature of ELSD was set to 60 °C and nebulizer gas pressure was 4.0 Bar. Method validation was performed to assure its linearity, limits of detection and quantification, precision, repeatability, stability, and accuracy.@*RESULTS@#The HPLC-DAD-ELSD method allowed the quantification of ten compounds (phellodendrine, jatrorrhizine, palmatine, berberine, neomangiferin, mangiferin, timosaponin E-I, timosaponin B-II, timosaponin B, and timosaponin A-III), and was successfully applied to fingerprint analysis for ten batches of ZB samples.@*CONCLUSION@#This was the first time to apply the combination of DAD and ELSD for the simultaneous determination of ten active ingredients in ZB. The results showed that the combination of quantitative analysis for marker ingredients and chemical fingerprint for the TCM herb pair provides a potentially powerful, widely introduced, and internationally accepted strategy for assessment of complex TCM formulas.