A sensitive and enantioselective vancomycin chiral stationary phase high-performance liquid chromatography–tandem mass spectrometry method was developed for the determination of trantinterol enantiomers in human plasma. Baseline resolution was achieved using the vancomycin chiral stationary phase known as Chirobiotic V with polar ionic mobile phase consisting of acetonitrile–methanol (60:40, v/v) containing 0.01% ammonia and 0.02% acetic acid at a flow rate of 1.0 mL/min. Waters Oasis HLB C18 solid phase extraction cartridges were used in the sample preparation of trantinterol samples from plasma. The detection was performed on a triple-quadrupole tandem mass spectrometer by multiple reaction monitoring mode via electrospray ionization. The calibration curve was linear in a concentration range from 0.0606 to 30.3 ng/mL in plasma, with the lower limit of quantification of 0.0606 ng/mL. The intra- and interday precision (relative standard deviation) values were within 9.7% and the accuracy (relative error) was from −6.6 to 7.2% at all quality control levels. The method was successfully applied to a study of stereoselective pharmacokinetics in human. Chirality 27:327–331, 2015.© 2015 Wiley Periodicals, Inc.

The chiral inversion and pharmacokinetics of two enantiomers of trantinterol, a new β₂ agonist, were studied in rats dosed (+)- or (−)-trantinterol separately. Plasma concentrations of (+)- and (−)-trantinterol were measured by chiral stationary phase liquid chromatography tandem mass spectroscopy (LC-MS/MS). The apparent inversion ratio was calculated as the ratio of AUC_0-t of (−)-trantinterol or (+)-trantinterol inverted from their antipodes to the sum of the AUC_0-t of (−)- and (+)-trantinterol. Following single intravenous administration, both given enantiomers declined in similar plasma concentrations, suggesting that the two enantiomers have approximately the same disposition kinetics by the route of intravenous administration. However, after single oral administration, plasma concentrations of uninverted (−)-trantinterol at many timepoints were significantly higher than those of uninverted (+)-trantinterol, suggesting that the two enantiomers undergo apparently different absorption or metabolism after oral administration. Significant bidirectional chiral inversion occurred after intravenous and oral administration of (+)- or (−)-trantinterol. After dosing with optically pure enantiomer, the concentration of the administered enantiomer predominated in vivo. The AUC_0-36 of (+)-trantinterol after intravenous and oral dosing of (−)-trantinterol were 16.6 ± 5.2 and 33.3 ± 16%, respectively of those of total [(+) + (−)] trantinterol. The AUC_0-36 of (−)-trantinterol after intravenous and oral dosing of (+)-trantinterol were 19.6 ± 8.8 and 37.9 ± 4.5%, respectively, of those of total [(−) + (+)] trantinterol. After intravenous administration of (+)- and (−)-trantinterol the chiral inversion ratios of the two enantiomers were not significantly different and similar results were found for oral administration. The extent of chiral inversion after intravenous administration was apparently lower, indicating that the bidirectional chiral inversion was not only systemic but also presystemic. Chirality 25:934–938, 2013.© 2013 Wiley Periodicals, Inc.

A simple, sensitive, and rapid method for determination of L-trantinterol in rat plasma was developed for the first time by using LC coupled to MS/MS based on chiral stationary phase. A baseline separation of the enantiomers of trantinterol was achieved on a Chirobiotic V column, using a mixture of acetonitrile–methanol–ammonia–acetic acid (80:20:0.01:0.02, v/v/v/v) as the mobile phase. The detection was performed on a triple-quadrupole tandem mass spectrometer by multiple reaction monitoring mode via ESI. The calibration curve was linear in concentration range from 0.270 to 108 ng/mL in plasma with the lower limit of quantification of 0.270 ng/mL. The intra- and interday precision (relative standard deviation) values were within 10.9% and the accuracy (relative error) was from 2.6 to 9.2% at all quality control levels. The method has been successfully applied to a study of L-trantinterol pharmacokinetics in rats.

High-speed counter-current chromatography (HSCCC) was successfully applied for the preparative separation and purification of alkaloids from Corydalis bungeana Turcz. (Kudiding in Chinese) for the first time. After the measurement of partition coefficient of seven target alkaloids in the nine two-phase solvent systems composed of CHCl₃–MeOH–(0.1 M; 0.2 M; 0.3 M) HCl (4:1.5:2; 4:2:2; 4:3:2, v/v), CHCl₃–MeOH–0.2 M HCl (4:2:2, v/v) and CHCl₃–MeOH–0.3 M HCl (4:3:2, v/v) were finally selected for the HSCCC separation using the first upper phase as the stationary phase and the stepwise elution of the two lower mobile phases. Consequently, sanguinarine (10 mg), corynoline (25 mg), protopine (20 mg), corynoloxine (18 mg), and 12-hydroxycorynoline (8 mg) were obtained from 200 mg of crude alkaloid extracts with purities of 94–99% as determined by HPLC. Their chemical structures were characterized on the basis of ¹H-NMR, ¹³C-NMR, and LC-ESI-Q-TOF-MS/MS analyses.

Introduction – Chiisanogenin existing in many Acanthopanax species has been reported to possess anti-inflammatory, antibacterial and antiplatelet aggregatory activities.

Objective – To develop and validate a rapid and sensitive ultra performance liquid chromatography-tandem mass spectrometry method for the determination of chiisanogenin in rat plasma and to investigate its pharmacokinetics after oral administration of chiisanogenin or the extract of Acanthopanax sessiliflorus fruits.

Methodology – The sample pretreatment involved a one-step extraction of 0.2 mL plasma with diethyl ether. Acetaminophen was used as the internal standard. The separation was carried out on an ACQUITY UPLC™ BEH C₁₈ column with a mobile phase of acetonitrile-5 mM ammonium acetate (90:10, v/v) at a flow rate of 0.2 mL/min. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) mode via electrospray ionization (ESI) source.

Results – A high sample throughput was achieved with an analysis time of 1.1 min per sample. The calibration curve was linear (r² ≥ 0.99) over the concentration range of 5–500 ng/mL with a lower limit of quantification (LLOQ) of 5 ng/mL. The intra-day and inter-day precision (relative standard deviation, R.S.D.) values were below 11% and the accuracy (relative error, R.E.) was within 8% at all three quality control (QC) levels.

Conclusion – The method was successfully applied to the pharmacokinetic study of chiisanogenin in rat after oral administration of chiisanogenin and the extract of Acanthopanax sessiliflorus fruits. Other constituents in the extract affected the pharmacokinetic behavior of chiisanogenin. Copyright © 2010 John Wiley & Sons, Ltd.

The enantioselective pharmacokinetics of tenatoprazole were studied in Wistar rats after the administration of a single oral dose of rac-tenatoprazole. Serial plasma samples were collected; and the pharmacokinetic behavior of each enantiomer was characterized using a sequential achiral and chiral liquid chromatographic method. Tenatoprazole was extracted from a small aliquot of plasma (100 μl) by one-step extraction using hexane-dichloromethane-isopropanol (20:10:1, v/v/v) as extract solvent. Plasma drug concentration–time data were analyzed for each enantiomer by using a noncompartmental method. The AUC_0−∞ and C_max values of (+)-tenatoprazole were significantly greater than those of (−)-tenatoprazole (P < 0.001). The mean AUC_0−∞ value of (+)-tenatoprazole was 7.5 times greater than that of (−)-tenatoprazole after oral administration of rac-tenatoprazole to rats at a dose of 5 mg/kg. There are also significant differences in t_1/2 and CL/F (P < 0.01and P < 0.001, respectively) values between enantiomers. This study suggests that the pharmacokinetics of tenatoprazole are enantioselective in rats. Chirality, 2008. © 2009 Wiley-Liss, Inc.

A new and accurate HPLC method using sulfobutylether-beta-cyclodextrin (SBE-beta-CD) as chiral mobile phase additive (CMPA) was developed and validated for the determination of R-(+)pantoprazole in S-(–)pantoprazole. The influences of type and concentration of CD, ACN content and buffer pH of mobile phase on the resolution and retention of enantiomers were investigated. A baseline resolution of pantoprazole enantiomers was achieved on a Spherigel C18 column (150 mm×4.6 mm, 5 μm) using ACN and 10 mM phosphate buffer (pH 2.5) containing 10 mM SBE-beta-CD (15:85 v/v) as mobile phase with a flow rate of 0.9 mL/min at 20°C. The detection wavelength was set at 290 nm. The method was extensively validated in terms of accuracy, precision and linearity according to the International Conference on Harmonisation (ICH) guidelines and proved to be robust. The LOD and LOQ for R-(+)pantoprazole were 0.2 and 0.5 μg/mL, respectively, with 5 μL injection volume. A good linear relationship was obtained in the concentration range of 0.5–6.0 μg/mL with r² >0.999 for R-(+)pantoprazole. The percentage recovery of the R-(+)pantoprazole ranged from 92.1 to 101.2 in bulk drug of S-(–)pantoprazole. The method is capable of determining a minimum limit of 0.05% w/w of R-enantiomer in S-(–)pantoprazole bulk samples.

The simultaneous capillary electrophoretic enantioseparation of adrenergic β₂-agonists enantiomers (trantinterol, mabuterol, clenbuterol, bambuterol) was studied with β-cyclodextrin, ethyl-β-CD, methyl-β-CD, hydroxypropyl-β-CD, and hydroxyethyl-β-CD as chiral selector. The type and concentration of the chiral selector and buffer pH played a very important role in the enantioseparation of the analyzed compounds. Hydroxypropyl-β-CD was found to be the most effective complexing agent and allowed excellent chiral/achiral resolutions compared to the other CDs. The simultaneous enantioseparation of four β₂-agonists was achieved using 100 mM citric acid–10 mM Na₂HPO₄ buffer at pH 2.5 containing 120 mM hydroxypropyl-β-CD with an applied voltage of 20 kV. Method validation in terms of repeatability, linearity, and limits of detection and quantification was performed. The effect of structural features of analytes on R_s and t_m was studied. Complexation binding constants for the interactions between the four compounds and three different CDs were evaluated for elucidating the enantioseparation mechanism. It was found that very small differences in the chemical structure of the analytes resulted in significant changes in stereoselective recognition.