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Thomas A, Thevis M. Stereoisomers in sports drug testing: Analytical strategies and applications. J Chromatogr A 2022; 1674:463154. [DOI: 10.1016/j.chroma.2022.463154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 05/12/2022] [Accepted: 05/16/2022] [Indexed: 10/18/2022]
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2
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Borgna F, Deberle LM, Busslinger SD, Tschan VJ, Walde LM, Becker AE, Schibli R, Müller C. Preclinical Investigations to Explore the Difference between the Diastereomers [ 177Lu]Lu-SibuDAB and [ 177Lu]Lu-RibuDAB toward Prostate Cancer Therapy. Mol Pharm 2022; 19:2105-2114. [PMID: 35544699 DOI: 10.1021/acs.molpharmaceut.1c00994] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
[177Lu]Lu-Ibu-DAB-PSMA, a radioligand modified with ibuprofen as the albumin binder, showed higher accumulation in PSMA-positive tumors of mice than the clinically used [177Lu]Lu-PSMA-617 but lower retention in non-targeted tissues than previously developed albumin-binding PSMA radioligands. The aim of this study was to investigate whether the stereochemistry of the incorporated ibuprofen affects the radioligand's in vitro and in vivo properties and to select the more favorable radioligand for further development. For this purpose, SibuDAB and RibuDAB containing (S)- and (R)-ibuprofen, respectively, were synthesized and labeled with lutetium-177. In vitro, the two isomers had similar properties; however, [177Lu]Lu-SibuDAB showed increased binding to mouse and human plasma proteins (91 ± 1 and 88 ± 2%, respectively) compared to [177Lu]Lu-RibuDAB (75 ± 2 and 79 ± 2%, respectively). In vivo, [177Lu]Lu-SibuDAB was metabolically more stable than [177Lu]Lu-RibuDAB with ∼90 vs ∼67% intact radioligand detected in the blood at 4 h post injection (p.i.). In line with the lower albumin-binding affinity, the blood clearance of [177Lu]Lu-RibuDAB in mice was considerably faster [27% of injected activity (% IA), 1 h p.i.] than for [177Lu]Lu-SibuDAB (50% IA, 1 h p.i.). Time-dependent biodistribution studies performed in tumor-bearing athymic nude mice showed high PSMA-specific tumor uptake for both isomers. A twofold increased area under the curve (AUC0→8d) of the blood retention was determined for [177Lu]Lu-SibuDAB as compared to [177Lu]Lu-RibuDAB, whereas the kidney AUC0→8d value of [177Lu]Lu-SibuDAB was only half as high as for [177Lu]Lu-RibuDAB. As a result, a more favorable tumor-to-kidney AUC0→8d ratio was obtained for [177Lu]Lu-SibuDAB, which was also visualized on SPECT/CT images. Based on its improved kidney clearance and higher metabolic stability, [177Lu]Lu-SibuDAB was selected as the more favorable radioligand. Therapy studies performed with [177Lu]Lu-SibuDAB (5 MBq/mouse) demonstrated the anticipated therapeutic superiority over the current gold-standard [177Lu]Lu-PSMA-617 (5 MBq/mouse). The significantly increased survival time of mice treated with [177Lu]Lu-SibuDAB as compared to those injected with [177Lu]Lu-PSMA-617 justifies further development of this novel radioligand toward clinical application.
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Affiliation(s)
- Francesca Borgna
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, Villigen-PSI 5232, Switzerland
| | - Luisa M Deberle
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, Villigen-PSI 5232, Switzerland
| | - Sarah D Busslinger
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, Villigen-PSI 5232, Switzerland
| | - Viviane J Tschan
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, Villigen-PSI 5232, Switzerland
| | - Laura M Walde
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, Villigen-PSI 5232, Switzerland
| | - Anna E Becker
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, Villigen-PSI 5232, Switzerland
| | - Roger Schibli
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, Villigen-PSI 5232, Switzerland.,Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich 8093, Switzerland
| | - Cristina Müller
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, Villigen-PSI 5232, Switzerland.,Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich 8093, Switzerland
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Cutolo G, Shankar SN, Pratt MR. Your mother was right, washing matters: An alkyne-analog of ibuprofen reveals unwanted reactivity of aromatic compounds with proteins during copper-catalyzed click chemistry. Bioorg Med Chem Lett 2021; 48:128260. [PMID: 34265422 DOI: 10.1016/j.bmcl.2021.128260] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 07/06/2021] [Accepted: 07/08/2021] [Indexed: 10/20/2022]
Abstract
Bioorthogonal chemistry, in particular the copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC), has enabled the robust identification of covalent protein targets of probes and drugs. Ibuprofen is commonly used pain and fever reducer and is sold as an enantiomeric racemate. Interestingly, the stereoisomers can be enzymatically converted through an ibuprofen-CoA thioester intermediate, which might non-specifically react with protein nucleophiles. Here, we use an alkyne-analog of ibuprofen to make two discoveries. First, we find that ibuprofen likely does not result in notable chemical labeling of proteins. However, we secondly find that aromatic compounds can react with proteins during the CuAAC reaction unless they are appropriately washed out of the mixture. This second discovery of false positive labeling has important technical implications for the application of this approach.
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Affiliation(s)
- Giuliano Cutolo
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, United States
| | - Sahiti N Shankar
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, United States
| | - Matthew R Pratt
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, United States; Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, United States.
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The investigation on ibuprofen methyl ester isomerization as a fundamental stage in the preparation of antipyretic medicine (R)-ibuprofen: a computational insight. Theor Chem Acc 2020. [DOI: 10.1007/s00214-020-02618-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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5
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Hadidi S, Shiri F, Norouzibazaz M. A computational study on phenibut lactamization mechanism and the pH effects on the process. Theor Chem Acc 2020. [DOI: 10.1007/s00214-020-02617-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Hadidi S, Shiri F, Norouzibazaz M. An investigation of pregabalin lactamization process and effect of various pH on reaction: A computational insight. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2020.128048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Hadidi S, Shiri F, Norouzibazaz M. Theoretical mechanistic insight into the gabapentin lactamization by an intramolecular attack: Degradation model and stabilization factors. J Pharm Biomed Anal 2020; 178:112900. [PMID: 31629973 DOI: 10.1016/j.jpba.2019.112900] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 09/02/2019] [Accepted: 09/28/2019] [Indexed: 10/25/2022]
Abstract
PURPOSE Gabapentin is degraded directly into a high toxicity form known as gabapentin lactam (gaba-L) with a maximizing desire in mild pH and low humidity. This study reports the lactamization process of gabapentin, along with a detailed analysis of the energy landscape, geometry, and thermodynamic and kinetic preference of the process. To investigate the effect of the acidic/basic conditions on the energy landscape, the energy profiles were investigated for both protonation and deprotonation forms of gabapentin. METHODS All the calculations were performed by using the density functional theory (DFT) and the G4MP2 levels of theory in the conductor-like polarizable continuum model, CPCM, and water as the solvent. RESULTS The lactamization process is an intramolecular cyclization which results in formation of gabapentin-lactam. The chemically intact gabapentin exists in two forms of a stable, R, and a relatively disordered form, R*. The conversion of stable crystalline form R to the intact unstable isomer R* is considered as the primary step in the gabapentin degradation. The results exhibited that near the unstable geometry, R*, a transition state (TS), is 41.3 kcal/mol higher in energy than the optimized ground state, R* (4.1 kcal/mol). From the intrinsic reaction coordinates (IRC) computations, it can be concluded that this transition state led to the unstable R* in one direction and to gabapentin-lactam in the other. CONCLUSIONS The thermodynamic stability of the lactam form (-13.63 kcal/mol) clarifies the more thermal stability of gaba-L than its related gabapentin form and the experimental preference for the lactamization. The corresponding energy profile on protonation/deprotonation forms of gabapentin indicates the pH-dependent of the process and the rate reduction in out of the mild pH.
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Affiliation(s)
- Saba Hadidi
- Department of Inorganic Chemistry, Faculty of Chemistry, Razi University, Kermanshah, Iran; Medical Biology Research Center (MBRC) Kermanshah University of Medical Sciences, Kermanshah, Iran.
| | - Farshad Shiri
- Department of Inorganic Chemistry, Faculty of Chemistry, Razi University, Kermanshah, Iran; Medical Biology Research Center (MBRC) Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Mohammadsaleh Norouzibazaz
- Nano Science and Technology Research Center, Razi University, Kermanshah, Iran; Department of Organic Chemistry, Faculty of Chemistry, Razi University, Kermanshah, Iran
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Pal M, Easton NM, Yaphe H, Bearne SL. Potent dialkyl substrate-product analogue inhibitors and inactivators of α-methylacyl-coenzyme A racemase from Mycobacterium tuberculosis by rational design. Bioorg Chem 2018; 77:640-650. [PMID: 29502025 DOI: 10.1016/j.bioorg.2018.01.041] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 01/28/2018] [Accepted: 01/30/2018] [Indexed: 12/15/2022]
Abstract
Rational approaches for the design of enzyme inhibitors furnish powerful strategies for developing pharmaceutical agents and tools for probing biological mechanisms. A new strategy for the development of gem-disubstituted substrate-product analogues as inhibitors of racemases and epimerases is elaborated using α-methylacyl-coenzyme A racemase from Mycobacterium tuberculosis (MtMCR) as a model enzyme. MtMCR catalyzes the epimerization at C2 of acyl-CoA substrates, a key step in the metabolism of branched-chain fatty acids. Moreover, the human enzyme is a potential target for the development of therapeutic agents directed against prostate cancer. We show that rationally designed, N,N-dialkylcarbamoyl-CoA substrate-product analogues inactivate MtMCR. Binding greatly exceeds that of the substrate, (S)-ibuprofenoyl-CoA, up to ∼250-fold and is proportional to the alkyl chain length (4-12 carbons) with the N,N-didecyl and N,N-didodecyl species having competitive inhibition constants with values of 1.9 ± 0.2 μM and 0.42 ± 0.04 μM, respectively. The presence of two decyl chains enhanced binding over a single decyl chain by ∼204-fold. Overall, the results reveal that gem-disubstituted substrate-product analogues can yield extremely potent inhibitors of an epimerase with a capacious active site.
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Affiliation(s)
- Mohan Pal
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Nicole M Easton
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Hannah Yaphe
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Stephen L Bearne
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada; Department of Chemistry, Dalhousie University, Halifax, NS B3H 4R2, Canada.
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de Bruin N, Ferreirós N, Schmidt M, Hofmann M, Angioni C, Geisslinger G, Parnham MJ. Mutual inversion of flurbiprofen enantiomers in various rat and mouse strains. Chirality 2018; 30:632-641. [DOI: 10.1002/chir.22826] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 01/10/2018] [Accepted: 01/10/2018] [Indexed: 12/17/2022]
Affiliation(s)
- Natasja de Bruin
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Research Center for Translational Medicine and Pharmacology TMP; Industriepark Höchst; Frankfurt am Main Germany
| | - Nerea Ferreirós
- Pharmazentrum Frankfurt/ZAFES; Institute of Clinical Pharmacology, Goethe-University Frankfurt; Frankfurt am Main Germany
| | - Mike Schmidt
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Research Center for Translational Medicine and Pharmacology TMP; Industriepark Höchst; Frankfurt am Main Germany
| | - Martine Hofmann
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Research Center for Translational Medicine and Pharmacology TMP; Industriepark Höchst; Frankfurt am Main Germany
| | - Carlo Angioni
- Pharmazentrum Frankfurt/ZAFES; Institute of Clinical Pharmacology, Goethe-University Frankfurt; Frankfurt am Main Germany
| | - Gerd Geisslinger
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Research Center for Translational Medicine and Pharmacology TMP; Industriepark Höchst; Frankfurt am Main Germany
- Pharmazentrum Frankfurt/ZAFES; Institute of Clinical Pharmacology, Goethe-University Frankfurt; Frankfurt am Main Germany
| | - Michael John Parnham
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Research Center for Translational Medicine and Pharmacology TMP; Industriepark Höchst; Frankfurt am Main Germany
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11
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León-González M, Rosales-Conrado N. Determination of ibuprofen enantiomers in breast milk using vortex-assisted matrix solid-phase dispersion and direct chiral liquid chromatography. J Chromatogr A 2017; 1514:88-94. [DOI: 10.1016/j.chroma.2017.07.072] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 07/19/2017] [Accepted: 07/20/2017] [Indexed: 11/30/2022]
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12
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Przejczowska-Pomierny K, Włodyka M, Cios A, Wyska E. Enantioselective analysis of ibuprofen enantiomers in mice plasma and tissues by high-performance liquid chromatography with fluorescence detection: Application to a pharmacokinetic study. Chirality 2017; 29:500-511. [DOI: 10.1002/chir.22715] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Revised: 04/23/2017] [Accepted: 04/26/2017] [Indexed: 11/10/2022]
Affiliation(s)
| | - Monika Włodyka
- Department of Pharmacokinetics and Physical Pharmacy; Jagiellonian University Medical College; Cracow Poland
| | - Agnieszka Cios
- Department of Pharmacokinetics and Physical Pharmacy; Jagiellonian University Medical College; Cracow Poland
| | - Elżbieta Wyska
- Department of Pharmacokinetics and Physical Pharmacy; Jagiellonian University Medical College; Cracow Poland
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Ikuta H, Kawase A, Iwaki M. Stereoselective Pharmacokinetics and Chiral Inversion of Ibuprofen in Adjuvant-induced Arthritic Rats. Drug Metab Dispos 2016; 45:316-324. [PMID: 27927688 DOI: 10.1124/dmd.116.073239] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 12/01/2016] [Indexed: 11/22/2022] Open
Abstract
2-Arylpropionic acid (2-APA) nonsteroidal anti-inflammatory drugs are commonly used in racemic mixtures (rac) for clinical use. 2-APA undergoes unidirectional chiral inversion of the in vivo inactive R-enantiomer to the active S-enantiomer. Inflammation causes the reduction of metabolic activities of drug-metabolizing enzymes such as cytochrome P450 (P450) and UDP-glucuronosyltransferase. However, it is unclear whether inflammation affects the stereoselective pharmacokinetics and chiral inversion of 2-APA such as ibuprofen (IB). We examined the effects of inflammation on the pharmacokinetics of R-IB and S-IB after intravenous administration of rac-IB, R-IB, and S-IB to adjuvant-induced arthritic (AA) rats, an animal model of inflammation. The plasma protein binding of rac-IB, glucuronidation activities for R-IB and S-IB, and P450 contents of liver microsomes in AA rats were determined. Total clearance (CLtot) of IB significantly increased in AA rats, although the glucuronidation activities for IB, and P450 contents of liver microsomes decreased in AA rats. We presumed that the increased CLtot of IB in AA rats was caused by the elevated plasma unbound fraction of IB due to decreased plasma albumin levels in AA rats. Notably, CLtot of R-IB but not S-IB significantly increased in AA rats after intravenous administration of rac-IB. These results suggested that AA could affect drug efficacies after stereoselective changes in the pharmacokinetics of R-IB and S-IB.
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Affiliation(s)
- Hiroyuki Ikuta
- Department of Pharmacy, Faculty of Pharmacy, Kindai University, Higashi-osaka, Osaka, Japan
| | - Atsushi Kawase
- Department of Pharmacy, Faculty of Pharmacy, Kindai University, Higashi-osaka, Osaka, Japan
| | - Masahiro Iwaki
- Department of Pharmacy, Faculty of Pharmacy, Kindai University, Higashi-osaka, Osaka, Japan
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Pal M, Khanal M, Marko R, Thirumalairajan S, Bearne SL. Rational design and synthesis of substrate-product analogue inhibitors of α-methylacyl-coenzyme A racemase from Mycobacterium tuberculosis. Chem Commun (Camb) 2016; 52:2740-3. [PMID: 26759836 DOI: 10.1039/c5cc08096g] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
2,2-Bis(4-isobutylphenyl)propanoyl-CoA and 2,2-bis(4-t-butylphenyl)propanoyl-CoA are rationally designed, gem-disubstituted substrate-product analogues that competitively inhibit α-methylacyl-coenzyme A racemase from Mycobacterium tuberculosis with Ki values of 16.9 ± 0.6 and 21 ± 4 μM, respectively, exceeding the enzyme's affinity for the substrate by approximately 5-fold.
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Affiliation(s)
- Mohan Pal
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada.
| | - Mandar Khanal
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada.
| | - Ryan Marko
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada.
| | - Srinath Thirumalairajan
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada.
| | - Stephen L Bearne
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada. and Department of Chemistry, Dalhousie University, Halifax, NS B3H 4R2, Canada
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Khramtsova EA, Sosnovsky DV, Ageeva AA, Nuin E, Marin ML, Purtov PA, Borisevich SS, Khursan SL, Roth HD, Miranda MA, Plyusnin VF, Leshina TV. Impact of chirality on the photoinduced charge transfer in linked systems containing naproxen enantiomers. Phys Chem Chem Phys 2016; 18:12733-41. [PMID: 27098151 DOI: 10.1039/c5cp07305g] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The model reaction of photoinduced donor-acceptor interaction in linked systems (dyads) has been used to study the comparative reactivity of a well-known anti-inflammatory drug, (S)-naproxen (NPX) and its (R)-isomer. (R)- or (S)-NPX in these dyads is linked to (S)-N-methylpyrrolidine (Pyr) using a linear or cyclic amino acid bridge (AA or CyAA), to give (R)-/(S)-NPX-AA-(S)-Pyr flexible and (R)-/(S)-NPX-CyAA-(S)-Pyr rigid dyads. The donor-acceptor interaction is reminiscent of the binding (partial charge transfer, CT) and electron transfer (ET) processes involved in the extensively studied inhibition of the cyclooxygenase enzymes (COXs) by the NPX enantiomers. Besides that, both optical isomers undergo oxidative metabolism by enzymes from the P450 family, which also includes ET. The scheme proposed for the excitation quenching of the (R)- and (S)-NPX excited state in these dyads is based on the joint analysis of the chemically induced dynamic nuclear polarization (CIDNP) and fluorescence data. The (1)H CIDNP effects in this system appear in the back electron transfer in the biradical-zwitterion (BZ), which is formed via dyad photoirradiation. The rate constants of individual steps in the proposed scheme and the fluorescence quantum yields of the local excited (LE) states and exciplexes show stereoselectivity. It depends on the bridge's length, structure and solvent polarity. The CIDNP effects (experimental and calculated) also demonstrate stereodifferentiation. The exciplex quantum yields and the rates of formation are larger for the dyads containing (R)-NPX, which let us suggest a higher contribution from the CT processes with the (R)-optical isomer.
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Affiliation(s)
- E A Khramtsova
- Institute of Chemical Kinetics and Combustion SB RAS, Institutskaya st., 3, 630090 Novosibirsk, Russia.
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Camphanic acid chloride: a powerful derivatization reagent for stereoisomeric separation and its DMPK applications. Bioanalysis 2015; 7:3005-17. [DOI: 10.4155/bio.15.219] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background: Camphanic acid chloride has proven to be an efficient chiral derivatization reagent for determination of stereoisomers. Results: The utility of chemical derivatization of various stereoisomers containing hydroxy functional groups with camphanic acid chloride in the presence or absence of a base is highlighted. This procedure is shown to be relatively simple, fast and a cost-effective method of separating racemic drugs and stereoisomeric metabolites in biological matrices. Camphanic derivatives contain two additional chirogenic centers, which are found to enhance stereoisomeric separation on both traditional and chiral stationary phases. Conclusion: Four methodologies described herein for separation of multiple stereoisomers in biological samples confirm camphanic acid chloride to be a powerful chiral reagent for stereoisomeric resolution for drug metabolism and PK applications.
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Zapata-Escobar A, Manrique-Moreno M, Guerra D, Hadad CZ, Restrepo A. A combined experimental and computational study of the molecular interactions between anionic ibuprofen and water. J Chem Phys 2014; 140:184312. [DOI: 10.1063/1.4874258] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
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Qin F, Wang X, Jing L, Pan L, Cheng M, Sun G, Li F. Bidirectional Chiral Inversion of Trantinterol Enantiomers After Separate Doses to Rats. Chirality 2013; 25:934-8. [DOI: 10.1002/chir.22236] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Accepted: 07/25/2013] [Indexed: 11/11/2022]
Affiliation(s)
- Feng Qin
- Department of Analytical Chemistry, School of Pharmacy; Shenyang Pharmaceutical University; Shenyang People's Republic of China
| | - Xintao Wang
- Department of Analytical Chemistry, School of Pharmacy; Shenyang Pharmaceutical University; Shenyang People's Republic of China
| | - Lijuan Jing
- Department of Analytical Chemistry, School of Pharmacy; Shenyang Pharmaceutical University; Shenyang People's Republic of China
| | - Li Pan
- Department of Pharmaceutical Chemistry, School of Pharmaceutical Engineering; Shenyang Pharmaceutical University; Shenyang People's Republic of China
| | - Maosheng Cheng
- Department of Pharmaceutical Chemistry, School of Pharmaceutical Engineering; Shenyang Pharmaceutical University; Shenyang People's Republic of China
| | - Guoxiang Sun
- Department of Analytical Chemistry, School of Pharmacy; Shenyang Pharmaceutical University; Shenyang People's Republic of China
| | - Famei Li
- Department of Analytical Chemistry, School of Pharmacy; Shenyang Pharmaceutical University; Shenyang People's Republic of China
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Lloyd MD, Yevglevskis M, Lee GL, Wood PJ, Threadgill MD, Woodman TJ. α-Methylacyl-CoA racemase (AMACR): Metabolic enzyme, drug metabolizer and cancer marker P504S. Prog Lipid Res 2013; 52:220-30. [DOI: 10.1016/j.plipres.2013.01.001] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Revised: 01/14/2013] [Accepted: 01/15/2013] [Indexed: 10/27/2022]
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Pshenichnyuk SA, Modelli A. Electron attachment to antipyretics: possible implications of their metabolic pathways. J Chem Phys 2012; 136:234307. [PMID: 22779593 DOI: 10.1063/1.4727854] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The empty-level structures and formation of negative ion states via resonance attachment of low-energy (0-15 eV) electrons into vacant molecular orbitals in a series of non-steroidal anti-inflammatory drugs (NSAIDs), namely aspirin, paracetamol, phenacetin, and ibuprofen, were investigated in vacuo by electron transmission and dissociative electron attachment (DEA) spectroscopies, with the aim to model the behavior of these antipyretic agents under reductive conditions in vivo. The experimental findings are interpreted with the support of density functional theory calculations. The negative and neutral fragments formed by DEA in the gas phase display similarities with the main metabolites of these commonly used NSAIDs generated in vivo by the action of cytochrome P450 enzymes, as well as with several known active agents. It is concluded that xenobiotic molecules which possess pronounced electron-accepting properties could in principle follow metabolic pathways which parallel the gas-phase dissociative decay channels observed in the DEA spectra at incident electron energies below 1 eV. Unwanted side effects as, e.g., hepatoxicity or carcinogenicity produced by the NSAIDs under study in human organism are discussed within the "free radical model" framework, reported earlier to describe the toxic action of the well-known model toxicant carbon tetrachloride.
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Affiliation(s)
- Stanislav A Pshenichnyuk
- Institute of Molecule and Crystal Physics, Ufa Research Centre, Russian Academy of Sciences, Prospekt Oktyabrya 151, 450075 Ufa, Russia.
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Laplante SR, D Fader L, Fandrick KR, Fandrick DR, Hucke O, Kemper R, Miller SPF, Edwards PJ. Assessing atropisomer axial chirality in drug discovery and development. J Med Chem 2011; 54:7005-22. [PMID: 21848318 DOI: 10.1021/jm200584g] [Citation(s) in RCA: 492] [Impact Index Per Article: 37.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Steven R Laplante
- Department of Chemistry, Boehringer Ingelheim (Canada) Ltd., 2100 Cunard Street, Laval, Quebec, H7S 2G5, Canada.
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22
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Liu Y, Han P, Li XY, Shih K, Gu JD. Enantioselective degradation and unidirectional chiral inversion of 2-phenylbutyric acid, an intermediate from linear alkylbenzene, by Xanthobacter flavus PA1. JOURNAL OF HAZARDOUS MATERIALS 2011; 192:1633-1640. [PMID: 21794984 DOI: 10.1016/j.jhazmat.2011.06.088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 06/10/2011] [Accepted: 06/29/2011] [Indexed: 05/31/2023]
Abstract
Microbial degradation of the chiral 2-phenylbutyric acid (2-PBA), a metabolite of surfactant linear alkylbenzene sulfonates (LAS), was investigated using both racemic and enantiomer-pure compounds together with quantitative stereoselective analyses. A pure culture of bacteria, identified as Xanthobacter flavus strain PA1 isolated from the mangrove sediment of Hong Kong Mai Po Nature Reserve, was able to utilize the racemic 2-PBA as well as the single enantiomers as the sole source of carbon and energy. In the presence of the racemic compounds, X. flavus PA1 degraded both (R) and (S) forms of enantiomers to completion in a sequential manner in which the (S) enantiomer disappeared much faster than the (R) enantiomer. When the single pure enantiomer was supplied as the sole substrate, a unidirectional chiral inversion involving (S) enantiomer to (R) enantiomer was evident. No major difference was observed in the degradation intermediates with either of the individual enantiomers when used as the growth substrate. Two major degradation intermediates were detected and identified as 3-hydroxy-2-phenylbutanoic acid and 4-methyl-3-phenyloxetan-2-one, using a combination of liquid chromatography-mass spectrometry (LC-MS), and (1)H and (13)C nuclear magnetic resonance (NMR) spectroscopy. The biochemical degradation pathway follows an initial oxidation of the alkyl side chain before aromatic ring cleavage. This study reveals new evidence for enantiomeric inversion catalyzed by pure culture of environmental bacteria and emphasizes the significant differences between the two enantiomers in their environmental fates.
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Affiliation(s)
- Yishan Liu
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China
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23
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Cardellina JH, Vieira RC, Eccard V, Skerry J, Montgomery V, Campbell Y, Roxas-Duncan V, Leister W, LeClair CA, Maloney DJ, Padula D, Pescitelli G, Khavrutskii I, Hu X, Wallqvist A, Smith LA. Separation of Betti Reaction Product Enantiomers: Absolute Configuration and Inhibition of Botulinum Neurotoxin A. ACS Med Chem Lett 2011; 2:396-401. [PMID: 22102940 DOI: 10.1021/ml200028z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The racemic product of the Betti reaction of 5-chloro-8-hydroxyquinoline, benzaldehyde and 2-aminopyridine was separated by chiral HPLC to determine which enantiomer inhibited botulinum neurotoxin serotype A. When the enantiomers unexpectedly proved to have comparable activity, the absolute structures of (+)-(R)-1 and (-)-(S)-1 were determined by comparison of calculated and observed circular dichroism spectra. Molecular modeling studies were undertaken in an effort to understand the observed bioactivity and revealed different ensembles of binding modes, with roughly equal binding energies, for the two enantiomers.
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Affiliation(s)
- John H. Cardellina
- Division of Integrated Toxicology, U.S. Army Medical Research Institute for Infectious Diseases, Frederick, Maryland, United States
| | - Rebecca C. Vieira
- Division of Integrated Toxicology, U.S. Army Medical Research Institute for Infectious Diseases, Frederick, Maryland, United States
| | - Vanessa Eccard
- Division of Integrated Toxicology, U.S. Army Medical Research Institute for Infectious Diseases, Frederick, Maryland, United States
| | - Janet Skerry
- Division of Integrated Toxicology, U.S. Army Medical Research Institute for Infectious Diseases, Frederick, Maryland, United States
| | - Vicki Montgomery
- Division of Integrated Toxicology, U.S. Army Medical Research Institute for Infectious Diseases, Frederick, Maryland, United States
| | - Yvette Campbell
- Division of Integrated Toxicology, U.S. Army Medical Research Institute for Infectious Diseases, Frederick, Maryland, United States
| | - Virginia Roxas-Duncan
- Division of Integrated Toxicology, U.S. Army Medical Research Institute for Infectious Diseases, Frederick, Maryland, United States
| | - William Leister
- NIH Chemical Genomics Center, National Human Genome Research Institute, NIH, 9800 Medical Center Drive, MSC 3370, Bethesda, Maryland, United States
| | - Christopher A. LeClair
- NIH Chemical Genomics Center, National Human Genome Research Institute, NIH, 9800 Medical Center Drive, MSC 3370, Bethesda, Maryland, United States
| | - David J. Maloney
- NIH Chemical Genomics Center, National Human Genome Research Institute, NIH, 9800 Medical Center Drive, MSC 3370, Bethesda, Maryland, United States
| | - Daniele Padula
- Department of Chemistry, University of Pisa, Pisa, Italy
| | | | - Ilja Khavrutskii
- Biotechnology High Performance Computer Software Application Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Frederick, Maryland, United States
| | - Xin Hu
- Biotechnology High Performance Computer Software Application Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Frederick, Maryland, United States
| | - Anders Wallqvist
- Biotechnology High Performance Computer Software Application Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Frederick, Maryland, United States
| | - Leonard A. Smith
- Office of Chief Scientist, U.S. Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, United States
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24
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Lin W, Hayakawa T, Yanaguimoto H, Kuzuba M, Obara T, Ding G, Cui F, Inotsume N. Pharmacokinetic interaction of ibuprofen enantiomers in rabbits. J Pharm Pharmacol 2010; 56:317-21. [PMID: 15025856 DOI: 10.1211/0022357022845] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Abstract
The potential interaction between two ibuprofen enantiomers was studied after intravenous administration of R-(–)-, S-(+)- and racemic ibuprofen to rabbits. The total body clearance values calculated by compartmental model analysis (0.65+0.21 for R-(–)-ibuprofen and 0.63+0.34 for S-(+)-ibuprofen) after intravenous administration of the racemate of ibuprofen were significantly smaller than those of individual enantiomers (0.95+0.23 for R-(–)-ibuprofen and 1.03+0.23 for S-(+)-ibuprofen), indicating that the enantiomer–enantiomer interaction results in a mutual inhibition. The enantiomeric interaction in the pharmacokinetic behaviour of ibuprofen after racemic administration is considered to be a result of an alteration in the metabolic or excretion phase (or both) rather than stereoselective protein binding in the systemic distribution.
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Affiliation(s)
- Wenhui Lin
- Department of Pharmacology and Therapeutics, Hokkaido College of Pharmacy, Katsuraoka, Otaru 047-0264, Japan
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25
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Ding G, Liu Y, Sun J, Takeuchi Y, Toda T, Hayakawa T, Fukushima S, Kishimoto S, Lin W, Inotsume N. Effect of absorption rate on pharmacokinetics of ibuprofen in relation to chiral inversion in humans. J Pharm Pharmacol 2010; 59:1509-13. [DOI: 10.1211/jpp.59.11.0007] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Abstract
The effect of absorption rate on the pharmacokinetics of ibuprofen enantiomers was investigated in 12 healthy Han Chinese male volunteers following oral administration of immediate-release (IR) and sustained-release (SR) preparations containing racemic ibuprofen (rac-ibuprofen). The area under the curve of the plasma concentration-time curve (AUC; (mean ± s.d.) values for rac-ibuprofen were 192.90 ± 43.47 for the SR preparation and 195.90 ± 31.69 μg h mL−1 for the IR preparation. AUC values for the enantiomers after administration of the SR formulation were 55.38 ± 17.79 and 92.51 ± 30.68 μg h mL−1 for R- and S-ibuprofen, respectively, and were 65.94 ± 20.06 and 100.81 ± 32.28 μg h mL−1 for R- and S-ibuprofen after administration of the IR preparation. These values did not differ significantly. Cmax values were significantly decreased with the SR preparation: 25.11 ± 5.71, 12.24 ± 3.79 and 12.38 ± 3.55 μg mL−1 for rac-, R-, and S-ibuprofen, respectively, after administration of the SR preparation, vs 46.21 ± 8.20, 20.82 ± 5.90 and 23.46 ± 7.30 μg mL−1 for rac-, R-, and S-ibuprofen, respectively, after administration of the IR preparation. Mean residence time was significantly increased: 7.01 ± 1.29, 5.52 ± 1.25 and 7.04 ± 1.30 h for rac-, R-, and S-ibuprofen, respectively, after administration of the SR preparation vs 4.34 ± 0.89, 3.43 ± 0.64 and 4.51 ± 0.79 h for rac-, R-, and S-ibuprofen, respectively, after administration of the IR preparation. AUC values for S-ibuprofen were significantly larger than those for R-ibuprofen in both preparations, indicating unidirectional chiral inversion. The S/R ratio of serum concentrations of enantiomers was 1.78-fold higher at 6 h after administration of the SR preparation compared with the IR preparation (P < 0.01).
These results indicate that ibuprofen undergoes pre-systemic chiral inversion in parallel with a systemic process and that the clinical effects of rac-ibuprofen in humans depend on the absorption rate.
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Affiliation(s)
- Guohua Ding
- Department of Pharmacy, Heilongjiang Provincial Second Hospital, 159 Diduan Street, Harbin, Heilongjiang 150010, China
| | - Yang Liu
- Department of Pharmacy, Heilongjiang Provincial Second Hospital, 159 Diduan Street, Harbin, Heilongjiang 150010, China
| | - Jiewen Sun
- Department of Pharmacy, Heilongjiang Provincial Second Hospital, 159 Diduan Street, Harbin, Heilongjiang 150010, China
| | - Yuriko Takeuchi
- Division of Pharmacotherapy, Hokkaido Pharmaceutical University School of Pharmacy, 7-1 Katsuraoka, Otaru 047-0264, Japan
| | - Takaki Toda
- Division of Pharmacotherapy, Hokkaido Pharmaceutical University School of Pharmacy, 7-1 Katsuraoka, Otaru 047-0264, Japan
| | - Toru Hayakawa
- Division of Pharmacotherapy, Hokkaido Pharmaceutical University School of Pharmacy, 7-1 Katsuraoka, Otaru 047-0264, Japan
| | - Shoji Fukushima
- Department of Pharmaceutics, Faculty of Pharmaceutical Sciences, Kobe Gakuin University, 1-1-3 Koutou, Chuo-ku, Kobe 650-8586, Japan
| | - Shuichi Kishimoto
- Department of Pharmaceutics, Faculty of Pharmaceutical Sciences, Kobe Gakuin University, 1-1-3 Koutou, Chuo-ku, Kobe 650-8586, Japan
| | - Wenhui Lin
- Department of Pharmaceutics, Faculty of Pharmaceutical Sciences, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Nobuo Inotsume
- Division of Pharmacotherapy, Hokkaido Pharmaceutical University School of Pharmacy, 7-1 Katsuraoka, Otaru 047-0264, Japan
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26
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Ouazia D, Bearne SL. A continuous assay for alpha-methylacyl-coenzyme A racemase using circular dichroism. Anal Biochem 2009; 398:45-51. [PMID: 19854148 DOI: 10.1016/j.ab.2009.10.039] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2009] [Revised: 10/20/2009] [Accepted: 10/21/2009] [Indexed: 12/22/2022]
Abstract
alpha-Methylacyl-coenzyme A racemase (AMACR) catalyzes the epimerization of (2R)- and (2S)-methyl branched fatty acyl-coenzyme A (CoA) thioesters. AMACR is a biomarker for prostate cancer and a putative target for the development of therapeutic agents directed against the disease. To facilitate development of AMACR inhibitors, a continuous circular dichroism (CD)-based assay has been developed. The open reading frame encoding AMACR from Mycobacterium tuberculosis (MCR) was subcloned into a pET15b vector, and the enzyme was overexpressed and purified using metal ion affinity chromatography. The rates of MCR-catalyzed epimerization of either (2R)- or (2S)-ibuprofenoyl-CoA were determined by following the change in ellipticity at 279nm in the presence of octyl-beta-d-glucopyranoside (0.2%). MCR exhibited slightly higher affinity for (2R)-ibuprofenoyl-CoA (K(m)=48+/-5microM, k(cat)=291+/-30s(-1)), but turned over (2S)-ibuprofenoyl-CoA (K(m)=86+/-6microM, k(cat)=450+/-14s(-1)) slightly faster. MCR expressed as a fusion protein bearing an N-terminal His(6)-tag had a catalytic efficiency (k(cat)/K(m)) that was reduced 22% and 47% in the 2S-->2R and 2R-->2S directions, respectively, relative to untagged enzyme. The continuous CD-based assay offers an economical and efficient alternative method to the labor-intensive, fixed-time assays currently used to measure AMACR activity.
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Affiliation(s)
- Dahmane Ouazia
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada B3H 1X5
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27
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Clayden J, Moran W, Edwards P, LaPlante S. The Challenge of Atropisomerism in Drug Discovery. Angew Chem Int Ed Engl 2009; 48:6398-401. [DOI: 10.1002/anie.200901719] [Citation(s) in RCA: 503] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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28
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Clayden J, Moran W, Edwards P, LaPlante S. Atropisomerie als Herausforderung in der Medikamentenentwicklung. Angew Chem Int Ed Engl 2009. [DOI: 10.1002/ange.200901719] [Citation(s) in RCA: 147] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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29
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Escuder-Gilabert L, Martínez-Gómez MA, Villanueva-Camañas RM, Sagrado S, Medina-Hernández MJ. Microseparation techniques for the study of the enantioselectivity of drug-plasma protein binding. Biomed Chromatogr 2009; 23:225-38. [DOI: 10.1002/bmc.1134] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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30
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Darley DJ, Butler DS, Prideaux SJ, Thornton TW, Wilson AD, Woodman TJ, Threadgill MD, Lloyd MD. Synthesis and use of isotope-labelled substrates for a mechanistic study on human alpha-methylacyl-CoA racemase 1A (AMACR; P504S). Org Biomol Chem 2008; 7:543-52. [PMID: 19156321 DOI: 10.1039/b815396e] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Alpha-Methylacyl-CoA racemase (AMACR) is an important enzyme for the metabolism of branched-chain lipids and drugs. The enzyme is over-expressed in prostate and other cancers. AMACR 1A, the major splice variant, was purified from recombinant E. coli cells as a His-tag protein. Purified enzyme catalysed chiral inversion of both S- and R-2-methyldecanoyl-CoA, with an equilibrium constant of 1.09 +/- 0.14 (2S/2R). Reactions with (2)H-labelled substrate showed that loss of the alpha-proton was a prerequisite for chiral inversion. Reactions conducted in (2)H(2)O indicated that reprotonation was not stereospecific. These results are the first mechanistic study on any recombinant mammalian alpha-methylacyl-CoA racemase.
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Affiliation(s)
- Daniel J Darley
- Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath, BA2 7AY, United Kingdom
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31
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Hao H, Wang G, Sun J. Enantioselective Pharmacokinetics of Ibuprofen and Involved Mechanisms. Drug Metab Rev 2008; 37:215-34. [PMID: 15747501 DOI: 10.1081/dmr-200047999] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Although dexibuprofen (S-ibuprofen) was marketed in Austria and Switzerland, the racemate at various formulations is still extensively used worldwide, and there are no indications that the racemate will be replaced by the single enantiomer. Thus, elucidation of the characteristics and involved mechanisms of the chiral pharmacokinetics of racemic ibuprofen is of special importance for the understanding of the pharmacological and toxicological consequences, and for prediction of the clinically potential drug interactions and influence of the pathological states. Stereoselective pharmacokinetics and metabolism are common features for chiral nonsteroidal antiinflammatory drugs (NSAIDs) and especially for 2-arylpropionic acid derivatives characterized with a chiral center adjacent to the carboxyl group. Although the enantioselective pharmacokinetic characteristics of different NSAIDs should be treated case by case, they share similar mechanisms underlying the protein binding, metabolism and chiral inversion. Ibuprofen was the most extensively researched drug in terms of chiral characteristics and mechanisms. Therefore, elucidation of the mechanisms derived from research on ibuprofen may provide better understanding and prediction of other chiral drugs. This article attempts to elucidate the chiral pharmacokinetics and involved mechanisms of ibuprofen in comparison with other NSAIDs based on recent developments. Topics on history of ibuprofen, enantioselective analysis method, absorption, protein binding, conventional metabolism, metabolic chiral inversion, gene polymorphism, and biochemical developments were included. It is worth mentioning that some underlying biochemical mechanisms, especially for the metabolic chiral inversion and ethnic differences still remain to be seen. Further research is required to develop human-resourced researching model and to provide more evidence concerning the site of inversion, species variation, CYP450 gene polymorphisms, and biochemical mechanisms.
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Affiliation(s)
- Haiping Hao
- Key Lab of Drug Metabolism & Pharmacokinetics, China Pharmaceutical University, Nanjing, China
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32
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33
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Lloyd MD, Darley DJ, Wierzbicki AS, Threadgill MD. Alpha-methylacyl-CoA racemase--an 'obscure' metabolic enzyme takes centre stage. FEBS J 2008; 275:1089-102. [PMID: 18279392 DOI: 10.1111/j.1742-4658.2008.06290.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Branched-chain lipids are important components of the human diet and are used as drug molecules, e.g. ibuprofen. Owing to the presence of methyl groups on their carbon chains, they cannot be metabolized in mitochondria, and instead are processed and degraded in peroxisomes. Several different oxidative degradation pathways for these lipids are known, including alpha-oxidation, beta-oxidation, and omega-oxidation. Dietary branched-chain lipids (especially phytanic acid) have attracted much attention in recent years, due to their link with prostate, breast, colon and other cancers as well as their role in neurological disease. A central role in all the metabolic pathways is played by alpha-methylacyl-CoA racemase (AMACR), which regulates metabolism of these lipids and drugs. AMACR catalyses the chiral inversion of a diverse number of 2-methyl acids (as their CoA esters), and regulates the entry of branched-chain lipids into the peroxisomal and mitochondrial beta-oxidation pathways. This review brings together advances in the different disciplines, and considers new research in both the metabolism of branched-chain lipids and their role in cancer, with particular emphasis on the crucial role played by AMACR. These recent advances enable new preventative and treatment strategies for cancer.
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Affiliation(s)
- Matthew D Lloyd
- Department of Pharmacy & Pharmacology, Medicinal Chemistry, University of Bath, Claverton Down, Bath, UK.
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34
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Ali I, Gupta VK, Aboul-Enein HY, Singh P, Sharma B. Role of racemization in optically active drugs development. Chirality 2007; 19:453-63. [PMID: 17393472 DOI: 10.1002/chir.20397] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
U.S. Food and Drug Administration issues certain guidelines for marketing of optically active drugs as some enantiomers racemize into human body, leading to the generation of other antipodes, which may be toxic or ballast to the human beings. Moreover, racemization reduces the administrated dosage concentration as optically active enantiomer converted into its inactive counter part. Therefore, the study of racemization of such type of drugs is an important and urgent need of today. This article describes in vitro and in vivo racemization of optically active drugs. The racemization process of various optically active drugs has been discussed considering the effect of different variables i.e. pH, temperature, concentration of the drug, ionic concentration, etc. Attempts have also been made to discuss the mechanisms of racemization. Besides, efforts have been made to suggest the safe dosages of such type of drugs too.
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Affiliation(s)
- Imran Ali
- Department of Chemistry, Faculty of Natural Sciences, Jamia Millia Islamia University, Jamia Nagar, New Delhi, India
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35
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Trejtnar F, Král R, Pávek P, Wsól V. Stereoselective pharmacokinetics and metabolism of flobufen in guinea pigs. Chirality 2003; 15:724-9. [PMID: 12923810 DOI: 10.1002/chir.10288] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Stereoselective aspects of pharmacokinetics and metabolism of a chiral nonsteroidal antiinflammatory drug, flobufen, 4-(2', 4'-difluorobiphenyl-4-yl)-2-methyl-4-oxobutanoic acid, were studied in male guinea pigs after p.o. administration of racemic flobufen (rac-flobufen) at a dose of 10 mg/kg. Blood samples were collected at intervals over 16 h after the administration of rac-flobufen for the quantification of flobufen enantiomers and their respective metabolites in plasma by chiral high-performance liquid chromatography (HPLC). Compartmental pharmacokinetic analysis was used to determine pharmacokinetic parameters of R- and S-flobufen. The plasma concentrations of the S- and R-enantiomers differed significantly during the experimental period. The S/R-enantiomeric ratio in 7plasma reached a maximum value of 10.1 at 240 min postdose. The oral clearance value of R-flobufen was five times higher than S-flobufen. The other pharmacokinetic parameters (K(e), T(1/2), V(SS)/F, MRT) of the enantiomers also differed substantially. All four stereoisomers of the dihydrometabolite of flobufen were detected in plasma with varying concentrations. Metabolite 17203 [4-(2,4-difluorophenyl)-phenylacetic acid] exhibited a relatively longer residence time compared to that noted for the enantiomers of the parent compound. Pharmacokinetics of the flobufen enantiomers were stereoselective in guinea pigs. The metabolism of flobufen was complex. However, metabolite 17203 seemed to be the main metabolite of flobufen that may be responsible for its relatively long-lasting antiphlogistic and immunomodulatory effects.
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Affiliation(s)
- Frantisek Trejtnar
- Charles University in Prague, Faculty of Pharmacy, Department of Pharmacology and Toxicology, Hradec Králové, Czech Republic.
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36
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Mukherji M, Schofield CJ, Wierzbicki AS, Jansen GA, Wanders RJA, Lloyd MD. The chemical biology of branched-chain lipid metabolism. Prog Lipid Res 2003; 42:359-76. [PMID: 12814641 DOI: 10.1016/s0163-7827(03)00016-x] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Mammalian metabolism of some lipids including 3-methyl and 2-methyl branched-chain fatty acids occurs within peroxisomes. Such lipids, including phytanic and pristanic acids, are commonly found within the human diet and may be derived from chlorophyll in plant extracts. Due to the presence of a methyl group at its beta-carbon, the well-characterised beta-oxidation pathway cannot degrade phytanic acid. Instead its alpha-methylene group is oxidatively excised to give pristanic acid, which can be metabolised by the beta-oxidation pathway. Many defects in the alpha-oxidation pathway result in an accumulation of phytanic acid, leading to neurological distress, deterioration of vision, deafness, loss of coordination and eventual death. Details of the alpha-oxidation pathway have only recently been elucidated, and considerable progress has been made in understanding the detailed enzymology of one of the oxidative steps within this pathway. This review summarises these recent advances and considers the roles and likely mechanisms of the enzymes within the alpha-oxidation pathway.
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Affiliation(s)
- Mridul Mukherji
- The Oxford Centre for Molecular Sciences & The Dyson Perrins Laboratory, South Parks Road, Oxford OX1 3QY, UK
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37
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Doki K, Hayakawa T, Lin W, Yanaguimoto H, Ding G, Inotsume N. Effects of absorption rate on the pre-systemic chiral inversion of ibuprofen in rabbits. J Pharm Pharmacol 2003; 55:1091-7. [PMID: 12956898 DOI: 10.1211/0022357021404] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
The chiral inversion kinetics of ibuprofen was evaluated after intraduodenal administration of racemic ibuprofen in conventional powder form and sustained-released granules compared with intravenous administration in rabbits. The AUC ratios of the S-(+) and R-(-) enantiomers remained almost constant values with time up to 2 h after administration of sustained-release formulation, while those after administration of the powder increased with time. R-(-) enantiomer to S-(+) enantiomer inversion ratios after intraduodenal administration of the powder form and the sustained-release form, and after intravenous injection were calculated to be 1.63, 1.94 and 1.19, respectively, indicating that pharmacological effects may depend on the absorption rate in rabbits.
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Affiliation(s)
- Kosuke Doki
- Department of Pharmacology and Therapeutics, Hokkaido College of Pharmacy, 7-1 Katsuraoka, Otaru 047-0264, Hokkaido, Japan
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Abstract
In order to enable detailed studies of free fatty acid (FFA) metabolism, we recently introduced a method for the evaluation of tissue-specific FFA metabolism in vivo. The method is based on the simultaneous use of 14C-palmitate (14C-P) and the non-beta-oxidizable FFA analogue, [9,10-3H]-(R)-2-bromopalmitate (3H-R-BrP). Indices of total FFA utilization and incorporation into storage products are obtained from tissue concentrations of 3H and 14C, respectively, following intravenous administration of 3H-R-BrP and 14C-P and their disappearance from plasma into tissues. This review covers the basis for, and developments in, the methodology, as well as some of the applications to date. In the rat, the method has been used to characterize tissue-specific alterations in FFA metabolism in various situations, including skeletal muscle contraction, fasting, hyperinsulinemia, and various pharmacological manipulations. The results of all these studies clearly demonstrate tissue-level control of FFA utilization and metabolic fate, refuting the traditional view that FFA utilization is simply supply-driven. Recent developments enable the simultaneous evaluation of both tissue-specific FFA and glucose metabolism by integrating the use of 2-deoxyglucose and stable isotope-labeled glucose tracers. In conclusion, the 3H-R-BrP methodology, especially in combination with other tracers, represents a powerful tool for elucidation of tissue-specific fatty acid metabolism in vivo.
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Wsól V, Král R, Skálová L, Szotáková B, Trejtnar F, Flieger M. Stereospecificity and stereoselectivity of flobufen metabolic profile in male rats in vitro and in vivo: phase I of biotransformation. Chirality 2002; 13:754-9. [PMID: 11746815 DOI: 10.1002/chir.10005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Flobufen (F) is the original nonsteroidal antiinflammatory drug (NSAID) containing two enantiomers. The aim of this investigation was to elucidate the biotransformation pathway of F at chiral level in phase I of biotransformation. Stereoselectivity and stereospecificity of the respective enzymes were studied in male rats in vitro (microsomal and cytosolic fractions, hepatocytes suspension) and in vivo. The rac-F, (+)-R-F and (-)-S-F were used as substrates. Amounts of F enantiomers, 4-dihydroflobufen diastereoisomers (DHF) and other metabolites (M-17203, UM) were determined with a chiral HPLC method in two chromatographic runs on R,R-ULMO and allyl-terguride bonded columns. Stereoselective biotransformation of the two enantiomers of F was observed at all tested levels and significant bidirectional chiral inversion of enantiomers of F was observed in hepatocytes. Mean enantiomeric ratios of F concentrations (S-/R-), after rac-F incubations, ranging from 1.09 in cytosolic fraction to 18.23 in hepatocytes. Stereospecificity of the respective F reductases was also observed. (2R;4S)-DHF and (2S;4S)-DHF are the principal metabolites of F in microsomes and hepatocytes. Neither DHF diastereoisomers nor M-17203 were found in cytosolic fraction. Only the nonchiral metabolite, M-17203, was found in all urine and feces samples after oral administration of F.
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Affiliation(s)
- V Wsól
- Department of Biochemical Sciences, Faculty of Pharmacy, Charles University, Hradec Králové, Czech Republic.
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40
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Abstract
Doses of racemic ibuprofen ranging from 5 to 20 mg/kg body weight were administered intravenously (i.v.) and orally to broiler chickens and plasma concentration-time profiles for both ibuprofen enantiomers were determined. The absorption of ibuprofen was evaluated after a bolus administration of a commercially available suspension into the crop and proventriculus, respectively. An enterohepatic circulation as described for other nonsteroidal anti-inflammatory drugs (NSAIDs) in other species could be suggested for both enantiomers after i.v. and oral administration. Significantly higher area under the curve (AUC) values for S(+)-ibuprofen compared with R(-)-ibuprofen were collected after crop and proventriculus administration. Several factors could be responsible for the significant differences in AUC values between both enantiomers.
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Affiliation(s)
- B Vermeulen
- Laboratory of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Ghent University, Harelbekestraat 72, B-9000 Gent, Belgium
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Vermeulen B, Remon JP. Validation of a high-performance liquid chromatographic method for the determination of ibuprofen enantiomers in plasma of broiler chickens. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 2000; 749:243-51. [PMID: 11145061 DOI: 10.1016/s0378-4347(00)00428-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To characterise the pharmacokinetic properties of each enantiomer of ibuprofen in broiler chickens, a stereospecific HPLC method based on a alpha1-acid glycoprotein bonded chiral stationary phase has been validated. S-(+)-naproxen was used as internal standard. Enantiomers of ibuprofen and S-(+)-naproxen were baseline separated using a mobile phase consisting of 0.1 M phosphate buffer pH = 7 and 0.4% 2-propanol. The method is precise, specific, accurate and reproducible. Recoveries were higher than 80% and the limits of quantification for R-(-)- and S-(+)-ibuprofen were 1.16 and 1.37 microg ml(-1), respectively. The method seemed suitable for the pharmacokinetic studies of ibuprofen in chickens.
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Affiliation(s)
- B Vermeulen
- Laboratory of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Ghent University, Gent, Belgium
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Abstract
The R enantiomers of some of the 2-arylpropionic acid non-steroidal antiinflammatory drugs (NSAIDs) are known to undergo metabolic chiral inversion to their more pharmacologically active antipodes. This process is drug and species dependent and usually unidirectional. The S to R chiral inversion, on the other hand, is rare and has been observed, in substantial extents, only for ibuprofen in guinea pigs and 2-phenylpropionic acid in dogs. After i.p. administration of single doses of racemic ketoprofen or its optically pure enantiomers to male CD-1 mice and subsequent study of the concentration time-course of the enantiomers, we noticed substantial chiral inversion in both directions. Following racemic doses, no stereoselectivity in the plasma-concentration time courses was observed. After dosing with optically pure enantiomer, the concentration of the administered enantiomer predominated during the absorption phase. During the terminal elimination phase, however, the enantiomers had the same concentrations. Our observation is suggestive of a rapid and reversible chiral inversion for ketoprofen enantiomers in mice.
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Affiliation(s)
- F Jamali
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Canada
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Jamali F, Lovlin R, Corrigan BW, Davies NM, Aberg G. Stereospecific pharmacokinetics and toxicodynamics of ketorolac after oral administration of the racemate and optically pure enantiomers to the rat. Chirality 2000; 11:201-5. [PMID: 10079499 DOI: 10.1002/(sici)1520-636x(1999)11:3<201::aid-chir5>3.0.co;2-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
To determine the stereospecific pharmacokinetics and gastrointestinal permeability (GI) changes (surrogate measures of toxicity) in the rat following oral administration of S, R, and racemic ketorolac (KT), optically pure enantiomers (S and R 2.5 mg/kg), and racemic KT (5 mg/kg) were administered orally to male Sprague-Dawley rats and plasma samples were collected for 6 h post-dose for pharmacokinetic assessments. KT-induced changes in GI permeability were assessed using sucrose and 51Cr-EDTA as markers of gastroduodenal and distal intestinal permeability, respectively. After the racemate, R-KT was predominant in plasma (AUC S/R, 0.45). No significant differences in pharmacokinetic indices were evident following administration of the racemate as compared with individual enantiomers. In plasma, there was only negligible S-KT after administration of R-KT. After S-KT, on the other hand, AUC of R-KT was found to be 6.7% of that of S-KT. Both permeability markers showed considerable interanimal variability. Gastroduodenal permeability was significantly increased from baseline by the racemate but not by either of the two enantiomers administered alone. Permeability to 51Cr-EDTA was not significantly increased above baseline for any of the treatments. The plasma concentration of R-KT found after administration of S-KT may be from the < 2% chiral impurity which appears magnified due to its slower clearance as compared with its antipode. There is no evidence of a pharmacokinetic interaction between the enantiomers. Since 2.5 mg/kg S-KT is somewhat less toxic on the gastroduodenum than 5 mg/kg racemate, it may be a safer alternative to the latter, at least in the rat model.
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Affiliation(s)
- F Jamali
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Canada.
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Abstract
Stereoselectivity of the pharmacokinetics of the nonsteroidal anti-inflammatory drug flobufen, 4-(2', 4'-difluorobiphenyl-4-yl)-2-methyl-4-oxobutanoic acid, was studied in male Wistar rats after intravenous administration. Pharmacokinetic parameters and chiral inversion of flobufen enantiomers were studied after a bolus injection of the racemate and individual enantiomers (5 mg/kg). Determinations of the enantiomers in rat plasma were performed using chiral HPLC (terguride column). After i.v. administration of flobufen racemate, plasma levels of R-enantiomer decreased more rapidly. The S-/R-enantiomer ratio of AUCs after rac-flobufen was 13.3. The total plasma clearance value of S-flobufen was more than 10-fold lower than R-flobufen. The other pharmacokinetic parameters of the enantiomers were also significantly different. While only traces of R-enantiomer (less than 1%) were detected in rat plasma after S-flobufen administration, considerable conversion to the S-enantiomer was found after injection of R-flobufen (R-enantiomer AUC/S-enantiomer AUC = 0.52). The results indicate substantial stereoselectivity in the disposition of flobufen enantiomers in the rat, which is, at least in part, attributed to chiral bioconversion.
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Affiliation(s)
- F Trejtnar
- Charles University, Prague, Faculty of Pharmacy, Department of Pharmacology and Toxicology, Department of Biochemical Sciences, Hradec Kralove, Czech Republic.
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Sevoz C, Rousselle C, Benoît E, Buronfosse T. In vitro study of fenoprofen chiral inversion in rat: comparison of brain versus liver. Xenobiotica 1999; 29:1007-16. [PMID: 10574682 DOI: 10.1080/004982599238074] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The extent and the overall stereoselectivity of the combined steps involved in the chiral inversion of fenoprofen, a non-steroidal anti-inflammatory drug, was investigated in rat brain microsomes and cytosol. Results were compared with those obtained with the same liver subcellular compartments. Brain microsomes catalysed the stereoselective activation of the R(-)-enantiomer to its coenzyme A thioester with a specific activity approximately 10-fold less than that obtained with liver microsomes. Rat brain microsomes and cytosol mediated the racemization and hydrolysis of both R(-)- and S( + )-fenoprofenoyl-CoA. In brain fractions the epimerase activity was lower than in liver, whereas the hydrolysis process appeared more efficient. Thus, the data indicated that the three-step mechanism occurred in brain subcellular compartments leading to a minor chiral inversion of fenoprofen compared with that in liver.
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Affiliation(s)
- C Sevoz
- Unité associée de Toxicologie et Métabolisme Comparés des Xénobiotiques DGER-INRA, Ecole Nationale Vétérinaire de Lyon, France
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Oakes ND, Kjellstedt A, Forsberg GB, Clementz T, Camejo G, Furler SM, Kraegen EW, Ölwegård-Halvarsson M, Jenkins AB, Ljung B. Development and initial evaluation of a novel method for assessing tissue-specific plasma free fatty acid utilization in vivo using (R)-2-bromopalmitate tracer. J Lipid Res 1999. [DOI: 10.1016/s0022-2275(20)33520-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Knights KM. Role of hepatic fatty acid:coenzyme A ligases in the metabolism of xenobiotic carboxylic acids. Clin Exp Pharmacol Physiol 1998; 25:776-82. [PMID: 9784915 DOI: 10.1111/j.1440-1681.1998.tb02152.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
1. Formation of acyl-coenzymes (Co)A occurs as an obligatory step in the metabolism of a variety of endogenous substrates, including fatty acids. The reaction is catalysed by ATP-dependent acid:CoA ligases (EC 6.2.1.1-2.1.3; AMP forming), classified on the basis of their ability to conjugate saturated fatty acids of differing chain lengths, short (C2-C4), medium (C4-C12) and long (C10-C22). The enzymes are located in various cell compartments (cytosol, smooth endoplasmic reticulum, mitochondria and peroxisomes) and exhibit wide tissue distribution, with highest activity associated with liver and adipose tissue. 2. Formation of acyl-CoA is not unique to endogenous substrates, but also occurs as an obligatory step in the metabolism of some xenobiotic carboxylic acids. The mitochondrial medium-chain CoA ligase is principally associated with metabolism via amino acid conjugation and activates substrates such as benzoic and salicylic acids. Although amino acid conjugation was previously considered an a priori route of metabolism for xenobiotic-CoA, it is now recognized that these highly reactive and potentially toxic intermediates function as alternative substrates in pathways of intermediary metabolism, particularly those associated with lipid biosyntheses. 3. In addition to a role in fatty acid metabolism, the hepatic microsomal and peroxisomal long-chain-CoA-ligases have been implicated in the formation of the acyl-CoA thioesters of a variety of hypolipidaemic and peroxisome proliferating agents (e.g. clofibric acid) and of the R(-)-enantiomers of the commonly used 2-arylpropionic acid non-steroidal anti-inflammatory drugs (e.g. ibuprofen). In vitro kinetic studies using rat hepatic microsomes and peroxisomes have alluded to the possibility of xenobiotic-CoA ligase multiplicity. Although cDNA encoding a long-chain ligase have been isolated from rat and human liver, there is currently no molecular evidence of multiple isoforms. The gene has been localized to chromosome 4 and homology searches have revealed a significant similarity with enzymes of the luciferase family. 4. Increasing recognition that formation of a CoA conjugate increases chemical reactivity of xenobiotic carboxylic acids has led to an awareness that the relative activity, substrate specificity and intracellular location of the xenobiotic-CoA ligases may explain differences in toxicity. 5. Continued characterization of the human xenobiotic-CoA ligases in terms of substrate/inhibitor profiles and regulation, will allow a greater understanding of the role of these enzymes in the metabolism of carboxylic acids.
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Affiliation(s)
- K M Knights
- Department of Clinical Pharmacology, School of Medicine, Faculty of Health Sciences, Flinders University of South Australia, Australia.
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Itoh T, Saura Y, Tsuda Y, Yamada H. Stereoselectivity and enantiomer-enantiomer interactions in the binding of ibuprofen to human serum albumin. Chirality 1997; 9:643-9. [PMID: 9366025 DOI: 10.1002/(sici)1520-636x(1997)9:7<643::aid-chir1>3.0.co;2-8] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Binding of ibuprofen (IB) enantiomers to human serum albumin (HSA) was studied using a chiral fluorescent derivatizing reagent, which enabled the measurement of IB enantiomers at a concentration as low 5 x 10(-8) M. Scatchard analyses revealed that there were two classes of binding sites for both enantiomers. For the high affinity site, the number of the binding sites was one for both enantiomers, and the binding constant of R-IB was 2.3-fold greater than that of S-IB. The difference in the affinity at the high affinity site may result in the stereoselective binding of IB enantiomers at therapeutic concentrations. It was confirmed that the high affinity site of IB enantiomers is Site II (diazepam binding site) by using site marker ligands. Also, significant enantiomer-enantiomer interactions were observed in the binding. The binding data were quantitatively analyzed and a binding model with an assumption of competitive interactions only at the high affinity site simulated the binding characteristics of IB enantiomers fairly well.
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Affiliation(s)
- T Itoh
- Department of Pharmacokinetics and Biopharmaceutics, School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan.
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49
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Tan SC, Jackson SH, Swift CG, Hutt AJ. Stereospecific analysis of the major metabolites of ibuprofen in urine by sequential achiral-chiral high-performance liquid chromatography. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1997; 701:53-63. [PMID: 9389338 DOI: 10.1016/s0378-4347(97)00338-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A sequential achiral-chiral HPLC method has been developed for the stereospecific analysis of the two major urinary metabolites of ibuprofen, namely hydroxyibuprofen and carboxyibuprofen. Achiral analysis was carried out using a Partisil column (250x4.6 mm, 5 microm) and a mobile phase of hexane:ethanol (98.2:1.8, v/v) containing trifluoroacetic acid (TFA; 0.05%, v/v) at a flow-rate of 2.0 ml/min. The HPLC eluate containing the two metabolites was separately collected, evaporated under nitrogen and the residue dissolved in the mobile phase used for chiral chromatography. Chiral-phase analysis was carried out using a Chiralpak AD CSP (250x4.6 mm, 10 microm) with a mobile phase of hexane:ethanol (92:8, v/v) containing TFA (0.05%, v/v) at a flow-rate of 1.0 ml/min. In both assays the analytes were quantified by ultraviolet detection at a wavelength of 220 nm. Modification of the mobile-phase composition allowed the resolution of all six analytes in a single chromatographic run but with an increase in run time and consequent band broadening. The analytical method described allows the direct quantitation of the stereoisomers of both metabolites of ibuprofen in urine following the administration of therapeutic doses of the racemic drug to man.
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Affiliation(s)
- S C Tan
- Department of Pharmacy, King's College London, UK
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50
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Enantiospecific analysis of ibuprofen by high performance liquid chromatography: Determination of free and total drug enantiomer concentrations in serum and urine. Chromatographia 1997. [DOI: 10.1007/bf02490926] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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