LC-electrolyte switch in a contiguous time segments to analyze multi-components: Simultaneous determination of phenolic acids and iridoids in rat plasma after inhalation administration of Reduning aerosol.

The optimization of electrolytes, kinds and concentrations, in mobile phase for multiple constituents analyzing using high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS) was usually compromised to ensure good LC separation of partial components. However, the compromised electrolytes could lead to ionization suppression of some of the analytes. To solve the compromise of electrolytes within various components, taking phenolic acids and iridoids as a case, we used electrolyte switch in contiguous running time segments of UPLC-ESI-MS/MS to ensure chromatographic separation of chlorogenic acid, neochlorogenic acid and cryptochlorogenic acid and improve the response of geniposide. Then the method was applied for pharmacokinetic study of the four components in rat after inhaling Reduning aerosol for the first time. The complete separation of the three chlorogenic acid isomers was achieved and the LLOQs of neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid, and geniposide were 1, 1, 3, and 0.2 ng/mL, respectively. In conclusion, we developed a sensitive and time-saving LC-MS/MS method for the quantitative analysis of chlorogenic acid, neochlorogenic acid, cryptochlorogenic acid, and geniposide in rat plasma, and this method appears to be useful for pharmacokinetic studies of Reduning aerosol. The method provided a sight to alleviate compromise of electrolytes in mobile phase for HPLC-ESI-MS in analyzing multi-components.

Yang W ，Wang S ，Zhang G ，Wu S ，Chen T ，Wang Q ，Wei M ，Cheng W ，Gao Y ，Li Y ，Ye Z ... -  《-》

Simultaneous determination of neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid and geniposide in rat plasma by UPLC-MS/MS and its application to a pharmacokinetic study after administration of Reduning injection.

A simple, specific and sensitive ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was established and validated for simultaneous determination of neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid and geniposide in rat plasma using puerarin as an internal standard (IS). Plasma samples were pretreated by a one-step direct protein precipitation procedure with acetonitrile after acidified using as little as 50 μL plasma. Chromatographic separation was performed on an Acquity BEH C18 column (100 × 2.1 mm, 1.7 µm) at a flow rate of 0.2 mL/min by a gradient elution, using 0.2% acetic acid-methanol as mobile phase. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring via electrospray ionization source with negative ion mode. Calibration curves showed good linearity (r > 0.995) over wide concentration ranges. The intra- and inter-day precisions were <15%, and the accuracy was within ±8.0%. The validated method was successfully applied to a pharmacokinetic study of the four bioactive components in rats after intravenous administration of Reduning injection.

Wang Y ，Wen J ，Zheng W ，Zhao L ，Fu X ，Wang Z ，Xiong Z ，Li F ，Xiao W ... -  《-》

Simultaneous determination of four phenolic acids and seven alkaloids in rat plasma after oral administration of traditional Chinese medicinal preparation Jinqi Jiangtang Tablet by LC-ESI-MS/MS.

A rapid, sensitive and selective high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the simultaneous determination of four phenolic acids (neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid and ferulic acid) and seven alkaloids (berberine, epiberberine, coptisine, magnoflorine, berberubine, palmatine and jatrorrhizine) in rat plasma. After mixing with the internal standards tetrahydropalmatine (IS1) and rosmarinic acid (IS2), plasma samples were pretreated by protein precipitation using acetonitrile. The HPLC analysis was performed on an Agilent Eclipse plus C18 (4.6 mm×100 mm, 1.8 μm) column with mobile phase consisting of 0.1% formic acid aqueous solution and acetonitrile at a flow rate of 0.3 mL min(-1). The detection was accomplished for the analytes and internal standards using positive electrospray ionization for the alkaloids and negative electrospray ionization for the phenolic acids in multiple-reaction monitoring mode. The method showed a good linearity over a wide concentration range (r(2)>0.99). The lower limit of quantification of seven alkaloids was lower than 2 ng mL(-1) and that of four phenolic acids was less than 20 ng mL(-1). The developed method was applied to the pharmacokinetic study of 11 components after oral administration of traditional Chinese medicinal preparation Jinqi Jiangtang Tablet in rats.

Chang YX ，Ge AH ，Yu XA ，Jiao XC ，Li J ，He J ，Tian J ，Liu W ，Azietaku JT ，Zhang BL ，Gao XM ... -  《-》

UPLC-MS/MS determination and gender-related pharmacokinetic study of five active ingredients in rat plasma after oral administration of Eucommia cortex extract.

Eucommiae cortex (EC), the bark of Eucommia ulmoides Oliv., has been traditionally used to treat many diseases in China for more than 2000 years. The pharmacological effects are primarily attributed to the presence of lignans, iridoids and phenolics, which are main active ingredients in EC. First, to investigate the active ingredients that can be absorbed into the rat plasma according to which ingredients exhibit significant correlation of drug concentration-time curve. Second, to establish an efficient ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) method for simultaneous determination of ingredients absorbed in rat plasma. Finally, to investigate gender effect on the pharmacokinetics of the ingredients absorbed in male and female rats plasma after oral administration with EC extract. 18 ingredients from EC were detected by UPLC-MS/MS, 9 out of 18 ingredients were absorbed into rat plasma. And 5 ingredients exhibit significant correlation of drug concentration-time curve. They were pinoresinol di-O-β-d-glucopyranoside (PDG), geniposide (GE), geniposidic acid (GA), aucubin (AN) and chlorogenic acid (CA). The analytes were extracted from rat plasma via a simple protein precipitation procedure and osalmid was used as the internal standard. Chromatographic separation was achieved on a Waters ACQUITY HSS T3 column (2.1mm×100mm, 1.8μm) using a gradient elution program with acetonitrile and 0.1% formic acid water as the mobile phase, with a flow rate of 0.3mLmin(-1). The detection was performed on a triple-quadrupole tandem mass spectrometer by multiple reactions monitoring (MRM) mode in a positive ion mode via electrospray ionization (ESI). The transition monitored were /z 683.00[M+H](+)→235.10 for PDG, / z 389.00[M+H](+)→208.80 for GE, m/z 375.00[M+H](+)→194.79 for GA, m/z 364.00[M+NH4](+)→148.81 for AN, m/z 355.10[M+H](+)→162.84 for CA and m/z 230.03[M+H](+)→120.77 for internal standard. The developed method showed good linearity over a wide concentration range, the lower limits of quantification and higher accuracy and precision for determination of the 5 analytes. Then the method was applied to study the pharmacokinetics in rats, and the results indicated that there were significant differences in pharmacokinetic parameters of the analytes between the male and female rats, and absorptions of these analytes in male group were all significantly higher than those in female group. This study established an efficient, sensitive and selective UPLC-MS/MS method for simultaneous determination of the five ingredients in rat plasma, and it could be successfully applied to the comparative pharmacokinetic studies in male and female rats after oral administration with EC extract.

Hu F ，An J ，Li W ，Zhang Z ，Chen W ，Wang C ，Wang Z ... -  《-》

Simultaneous determination of caffeic acid derivatives by UPLC-MS/MS in rat plasma and its application in pharmacokinetic study after oral administration of Flos Lonicerae-Fructus Forsythiae herb combination.

The current study aims to investigate the pharmacokinetic study of eight caffeic acid derivatives (forsythoside A, isoforsythoside, forsythoside B, neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid, 3,5-dicaffeoylquinic acid and 3,4-dicaffeoylquinic acid) following oral administration of Flos Lonicerae-Fructus Forsythiae herb combination in rats. A rapid and sensitive ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed to determine the eight caffeic acid derivatives simultaneously in rat plasma. After mixing with the internal standard (IS) tinidazole, plasma samples were pretreated by liquid-liquid extraction with n-butyl alcohol/ethyl acetate (7:3, v/v). The separation was performed on an Acquity UPLC HSS T3 C18 column (100mm×2.1mm, 1.8μm) at a flow rate of 0.4mLmin(-1), and acetonitrile/methanol (4:1, v/v)-0.4% formic acid was used as mobile phase. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) via electrospray ionization (ESI) source with positive and negative ionization modes. All calibration curves had good linearity (r>0.991) over the concentration ranges of 1.097-2246ngmL(-1) for neochlorogenic acid, 6.535-6692ngmL(-1) for chlorogenic acid, 2.103-2153ngmL(-1) for cryptochlorogenic acid, 0.5058-129.5ngmL(-1) for 3,5-dicaffeoylquinic acid, 0.3205-82.05ngmL(-1) for 3,4-dicaffeoylquinic acid, 1.002-512.8ngmL(-1) for isoforsythoside, 0.4795-982.1ngmL(-1) for forsythoside A and 0.7587-776.9ngmL(-1) for forsythoside B, respectively. The intra- and inter-batch precisions were all within 15% and the accuracy (relative error, RE%) all ranged from 85.68% to 114.7%. It was shown from pharmacokinetic parameters that the rank order of AUC0-t, Cmax and T1/2k for phenolic acids was chlorogenic acid>neochlorogenic acid≥cryptochlorogenic acid>3,4-dicaffeoylquinic acid≥3,5-dicaffeoylquinic acid (most of them had significant differences), which corresponded to their administration dosages to rats, but that of MRT0-t and T1/2z were opposite. Besides, the AUC0-t, Cmax, MRT and T1/2z except T1/2k of isoforsythoside and forsythoside B had no significant difference, compared to that of forsythoside A though their administration dosages were significantly lower than that of forsythoside A. All results showed that the method was applied to the pharmacokinetic study of the eight caffeic acid derivatives in rat plasma successfully after oral administration of Flos Lonicerae-Fructus Forsythiae herb combination, and there were significant differences of caffeic acid derivatives even isomers in the pharmacokinetic parameters.

Zhou W ，Shan J ，Wang S ，Ju W ，Meng M ，Cai B ，Di L ... -  《-》