Stereoselective liquid chromatographic determination of 1′‐oxobufuralol and 1′‐hydroxybufuralol in rat liver microsomal fraction using hollow‐fiber liquid‐phase microextraction for sample preparation

Barth, Thiago; Simões, Rodrigo Almeida; Pupo, Mônica Tallarico; Okano, Laura Tiemi; Bonato, Pierina Sueli

doi:10.1002/jssc.201100464

Cited by 8 publications

(4 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A mobile phase of methanol and 1.5% acetic acid at a ratio of 10:90 (v/v) was used at a flow rate of 1 ml/min. BF and 19-OH-BF were determined as reported by Barth et al (2011) and Mankowski (1999) with slight modifications. Briefly, BF and 19-OH-BF were monitored by UV detection at Fig.…”

Section: Methodsmentioning

confidence: 99%

Pharmacokinetics and Differential Regulation of Cytochrome P450 Enzymes in Type 1 Allergic Mice

et al. 2016

View full text Add to dashboard Cite

Type 1 allergic diseases are characterized by elevated production of specific immunoglobulin E (IgE) for each antigen and have become a significant health problem worldwide. This study investigated the effect of IgE-mediated allergy on drug pharmacokinetics. To further understand differential suppression of hepatic cytochrome P450 (P450) activity, we examined the inhibitory effect of nitric oxide (NO), a marker of allergic conditions. Seven days after primary sensitization (PS7) or secondary sensitization (SS7), hepatic CYP1A2, CYP2C, CYP2E1, and CYP3A activities were decreased to 45%-75% of the corresponding control; however, CYP2D activity was not downregulated. PS7 and SS7 did not change the expression levels of five P450 proteins. Disappearance of CYP1A2 and CYP2D substrates from the plasma was not significantly different between allergic mice and control mice. In contrast, the area under the curve of a CYP1A2-mediated metabolite in PS7 and SS7 mice was reduced by 50% of control values. Total clearances of a CYP2E1 substrate in PS7 and SS7 mice were significantly decreased to 70% and 50% respectively, of the control without altering plasma protein binding. Hepatic amounts of CYP1A2 and CYP2E1 substrates were enhanced by allergic induction, being responsible for each downregulated activity. NO scavenger treatment completely improved the downregulated P450 activities. Therefore, our data suggest that the onset of IgE-mediated allergy alters the pharmacokinetics of major P450-metabolic capacity-limited drugs except for CYP2D drugs. NO is highly expected to participate in regulatory mechanisms of the four P450 isoforms.

show abstract

Section: Methodsmentioning

confidence: 99%

Pharmacokinetics and Differential Regulation of Cytochrome P450 Enzymes in Type 1 Allergic Mice

et al. 2016

View full text Add to dashboard Cite

show abstract

“…In addition, it should be strongly immobilized in the pores of the hollow fiber, and should provide appropriate extraction selectivity. Considering these characteristics, octanol was selected as organic solvent . In three‐phase systems, the use of strong acids as acceptor phase results in better recoveries for basic analytes, due to the efficient analyte protonation at low pH values.…”

Section: Resultsmentioning

confidence: 99%

Combination of hollow‐fiber liquid‐phase microextraction and capillary electrophoresis for pioglitazone and its main metabolites determination in rat liver microsomal fraction

Calixto

Bonato

2013

Electrophoresis

View full text Add to dashboard Cite

Pioglitazone (PGZ), a thiazolidinedione antidiabetic agent, is reported as a potent and selective activator of peroxisome proliferator-activated receptor γ (PPAR γ). This drug has been widely prescribed for the treatment of Type 2 diabetes mellitus. In this regard, this manuscript presents, for the first time, an alternative electrophoretic method for PGZ and its main metabolites determination in rat liver microsomal fraction. The electrophoretic analyses were performed using an uncoated fused-silica capillary of 50 μm id, 48 cm in total length and 40 cm in effective length, and 50 mmol/L sodium phosphate buffer solution (pH 2.5). All experiments were carried out under the normal mode. The capillary temperature was set at 35°C and a constant voltage of +30 kV was applied during the analyses. Samples were introduced into the capillary by hydrodynamic injection (50 mbar, 15 s) and detection was performed at 190 nm. The sample preparation procedure, based on hollow-fiber liquid-phase microextraction, was optimized using multifactorial experiments. Next, the following optimal condition was established: sample agitation at 1500 rpm, extraction for 15 min, 0.01 mol/L hydrochloric acid as acceptor phase, 1-octanol as organic phase, and donor phase pH adjustment to 6.0. The method demonstrated LOQs of 200 ng/mL. Additionally, it was linear over the concentration range of 200-25,000 ng/mL for PGZ and 200-2000 ng/mL for the metabolites. Finally, the validated method was employed to study the in vitro metabolism of PGZ using rat liver microsomal fraction.

show abstract

“…Therefore, to determine the elution order of DPZ metabolites, a combination of chromatographic and CD methods was used [25,26]. Hence, the CD spectra of 5-ODD and 6-ODD enantiomers were compared with the CD spectra of DPZ enantiomers.…”

Section: Elution Order Determinationmentioning

confidence: 99%

Chiral HPLC analysis of donepezil, 5-O-desmethyl donepezil and 6-O-desmethyl donepezil in culture medium: application to fungal biotransformation studies

et al. 2012

Self Cite

View full text Add to dashboard Cite

An high performance liquid chromatography (HPLC) method for the enantioselective determination of donepezil (DPZ), 5-O-desmethyl donepezil (5-ODD), and 6-O-desmethyl donepezil (6-ODD) in Czapek culture medium to be applied to biotransformation studies with fungi is described for the first time. The HPLC analysis was carried out using a Chiralpak AD-H column with hexane/ethanol/methanol (75:20:5, v/v/v) plus 0.3 % triethylamine as mobile phase and UV detection at 270 nm. Sample preparation was carried out by liquid-liquid extraction using ethyl acetate as extractor solvent. The method was linear over the concentration range of 100-10,000 ng mL(-1) for each enantiomer of DPZ (r ≥ 0.9985) and of 100-5,000 ng mL(-1) for each enantiomer of 5-ODD (r ≥ 0.9977) and 6-ODD (r ≥ 0.9951). Within-day and between-day precision and accuracy evaluated by relative standard deviations and relative errors, respectively, were lower than 15 % for all analytes. The validated method was used to assess DPZ biotransformation by the fungi Beauveria bassiana American Type Culture Collection (ATCC) 7159 and Cunninghamella elegans ATCC 10028B. Using the fungus B. bassiana ATCC 7159, a predominant formation of (R)-5-ODD was observed while for the fungus C. elegans ATCC 10028B, DPZ was biotransformed to (R)-6-ODD with an enantiomeric excess of 100 %.

show abstract

Stereoselective liquid chromatographic determination of 1′‐oxobufuralol and 1′‐hydroxybufuralol in rat liver microsomal fraction using hollow‐fiber liquid‐phase microextraction for sample preparation

Cited by 8 publications

References 22 publications

Pharmacokinetics and Differential Regulation of Cytochrome P450 Enzymes in Type 1 Allergic Mice

Pharmacokinetics and Differential Regulation of Cytochrome P450 Enzymes in Type 1 Allergic Mice

Combination of hollow‐fiber liquid‐phase microextraction and capillary electrophoresis for pioglitazone and its main metabolites determination in rat liver microsomal fraction

Chiral HPLC analysis of donepezil, 5-O-desmethyl donepezil and 6-O-desmethyl donepezil in culture medium: application to fungal biotransformation studies

Contact Info

Product

Resources

About