A Rapid and Sensitive UPLC-MS/MS Method for Quantification of Bruceantinol in Rat Plasma and Its Application to a Pharmacokinetic Study.

Bruceantinol (BOL), a quassinoid compound isolated from the fruits of Brucea javanica, has been reported to have cytotoxic and antibacterial effects. In this study, a rapid, sensitive, and specific ultra-performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS) method was developed for the quantitative determination of BOL in rat plasma. The samples were treated by simple liquid-liquid extraction with ethyl acetate and separated on an UPLC BEH C18 column (2.1 mm × 50 mm) using a 3-min gradient elution scheme, which consists of water (0.1% v/v, formic acid) and methanol (0.1%, v/v, formic acid) to achieve the separation of BOL and sinomenine (IS) with high selectivity. The electrospray ionization source was used in positive ion mode; the multiple reaction monitoring quantified the target fragment ions m/z 629.6 → 569.5 for BOL and m/z 330.5 → 207.3 for IS. This work was evaluated with regards to the specificity, extraction recovery, matrix effect, linearity, accuracy, precision, stability, and dilution integrity. This approach was used to examine the pharmacokinetics of BOL in rats after oral (0.3 mg/kg) and intravenous (0.15 mg/kg) administration. BOL presented fast excretion and very low oral bioavailability.

HPLC-MS/MS method for bioavailability study of bruceines D & E in rat plasma.

Bruceines D and E are quassinoids from seeds of Brucea javanica (L.) Merr. exhibiting hypoglycemia effect. The crude drug is used as a traditional medicine by diabetes patients. The aim of this study is to understand the bioavailability and pharmacokinetics of both the bruceines D & E. A rapid and sensitive HPLC-MS/MS method was developed and validated for the quantification of both quassinoids, bruceines D & E in rat plasma. Both the bruceines D & E were separated with the Zorbax SBC-18 column with gradient elution and mobile phase system of acetonitrile and deionized water with 0.1% formic acid at a flow rate of 0.5mL/min. Analytes were detected in multiple reaction monitoring (MRM) mode with electrospray positive ionization. The quassinoids, namely bruceines D & E were detected with transitions of m/z 411.2→393.2 and m/z 395.2→377.2, respectively. Another quassinoid, eurycomanone was used as the internal standard with transition of m/z 409.2→391.2. The method was validated and conformed to the regulatory requirements. The validated method was applied to pharmacokinetic and bioavailability studies in rats. The pharmacokinetic study indicated both bruceine D and E were rapidly absorbed into the circulation system and reached its peak concentration at 0.54±0.34h and 0.66±0.30h, respectively. Bruceine E was eliminated slower than Bruceine D with t1/2 value almost increased two-fold compared to Bruceine D. In conclusion, a rapid, selective and sensitive HPLC-MS/MS method was developed for the simultaneous determination of both the bruceines D and E in rat plasma. Both bruceines D and E displayed poor oral bioavailability.

Determination of eurycomanone in rat plasma using hydrophilic interaction liquid chromatography-tandem mass spectrometry for pharmacokinetic study.

In this study, a rapid, sensitive, and reliable hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS) method for the determination of eurycomanone in rat plasma was developed and validated. Plasma samples were pretreated with a protein precipitation method and quercitrin was used as an internal standard (IS). A HILIC silica column (2.1 × 100 mm, 3 µm) was used for hydrophilic-based chromatographic separation, using the mobile phase of 0.1% formic acid with acetonitrile in gradient elution at a flow rate of 0.25 mL/min. Precursor-product ion pairs for multiple-reaction monitoring were m/z 409.1 → 391.0 for eurycomanone and m/z 449.1 → 303.0 for IS. The linear range was 2-120 ng/mL. The intra- and inter-day accuracies were between 95.5 and 103.4% with a precision of <4.2%. The developed method was successfully applied to the pharmacokinetic analysis of eurycomanone in rat plasma after oral dosing with pure compound and E. longifolia extract. The Cmax and AUC0-t , respectively, were 40.43 ± 16.08 ng/mL and 161.09 ± 37.63 ng h/mL for 10 mg/kg eurycomanone, and 9.90 ± 3.97 ng/mL and 37.15 ± 6.80 ng h/mL for E. longifolia extract (2 mg/kg as eurycomanone). The pharmacokinetic results were comparable with each other, based on the dose as eurycomanone.

Development and validation of liquid chromatography combined with tandem mass spectrometry methods for the quantitation of simalikalactone E in extracts of Quassia amara L. and in mouse blood.

INTRODUCTION: Simalikalactone E (SkE) from Quassia amara, has been proved to be a valuable anti-malarial and anti-cancer compound. As SkE is very scarce, methods of quantitation are needed in order to optimise its isolation process and to determine pharmacokinetic data. OBJECTIVE: To validate methods using liquid chromatography coupled to mass spectrometry for the quantitation of SkE in plant extracts and in biological fluids. METHODS: High- and ultrahigh-performance liquid chromatography (UHPLC) coupled to ion trap mass spectrometry (MS) with single ion monitoring detection and to triple quadrupole-linear ion trap tandem mass spectrometry with multiple reaction monitoring detection methods were developed. Validation procedure was realised according to the International Conference on Harmonisation guideline. Methanol extracts of dried Quassia amara leaves, and mouse-blood samples obtained after various routes of administration, were analysed for SkE. RESULTS: Methods were validated and gave similar results regarding the content of SkE expressed per kilogram of dry leaves in the traditional decoction (160 ± 12 mg/kg) and in the methanol extract (93 ± 2 mg/kg). The recovery of the analyte from mouse blood ranged from 80.7 to 119.8%. Simalikalactone E was only detected using UHPLC-MS/MS (0.2 ± 0.03 mg/L) in mouse blood after intravenous injection: none was detected following intraperitoneal or oral gavage administration of SkE. CONCLUSION: The LC-MS methods were used for the quantitation of SkE in plant extracts and in mouse blood. These methods open the way for further protocol optimisation of SkE extraction and the determination of its pharmacokinetic data.