1
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Ramig K, Greer EM, Szalda DJ, Karimi S, Ko A, Boulos L, Gu J, Dvorkin N, Bhramdat H, Subramaniam G. NMR Spectroscopic and Computational Study of Conformational Isomerism in Substituted 2-Aryl-3H-1-benzazepines: Toward Isolable Atropisomeric Benzazepine Enantiomers. J Org Chem 2013; 78:8028-36. [DOI: 10.1021/jo4013089] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Keith Ramig
- Department of Natural Sciences, Baruch College of the City University of New York,
17 Lexington Avenue, New York, New York 10010, United States
| | - Edyta M. Greer
- Department of Natural Sciences, Baruch College of the City University of New York,
17 Lexington Avenue, New York, New York 10010, United States
| | - David J. Szalda
- Department of Natural Sciences, Baruch College of the City University of New York,
17 Lexington Avenue, New York, New York 10010, United States
| | - Sasan Karimi
- Department of Chemistry, Queensborough Community College of the City University of New York, 222-05 56th Avenue, Bayside, New York 11364, United States
| | - Allen Ko
- Department of Natural Sciences, Baruch College of the City University of New York,
17 Lexington Avenue, New York, New York 10010, United States
| | - Laura Boulos
- Department of Natural Sciences, Baruch College of the City University of New York,
17 Lexington Avenue, New York, New York 10010, United States
| | - Jiansan Gu
- Department of Natural Sciences, Baruch College of the City University of New York,
17 Lexington Avenue, New York, New York 10010, United States
| | - Nathan Dvorkin
- Department of Natural Sciences, Baruch College of the City University of New York,
17 Lexington Avenue, New York, New York 10010, United States
| | - Hema Bhramdat
- Department of Chemistry and Biochemistry, Queens College of the City University of New York,
65-30 Kissena Boulevard, Flushing, New York 11367, United States
| | - Gopal Subramaniam
- Department of Chemistry and Biochemistry, Queens College of the City University of New York,
65-30 Kissena Boulevard, Flushing, New York 11367, United States
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2
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Interactions of acidic pharmaceuticals with human serum albumin: insights into the molecular toxicity of emerging pollutants. Amino Acids 2012; 43:1419-29. [DOI: 10.1007/s00726-012-1215-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Accepted: 01/02/2012] [Indexed: 11/27/2022]
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3
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Decorte E, Toso R, Fajdiga T, Comisso G, Moimas F, Sega A, Sunjić V, Lisini A. Chiral 1,4-benzodiazepines. XII. Conformation in a solution of 7-chloro-5-phenyl-3(S)methyl-1,3-dihydro-2H-1,4-benzodiazepine. J Heterocycl Chem 2009. [DOI: 10.1002/jhet.5570200534] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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4
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Organogold complexes probe a large β-barrel cavity for human serum α1-acid glycoprotein. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2008; 1784:1106-14. [DOI: 10.1016/j.bbapap.2008.03.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2008] [Revised: 03/20/2008] [Accepted: 03/24/2008] [Indexed: 11/22/2022]
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5
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Pistolozzi M, Bertucci C. Species-dependent stereoselective drug binding to albumin: A circular dichroism study. Chirality 2008; 20:552-8. [DOI: 10.1002/chir.20521] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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6
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Fitos I, Visy J, Zsila F, Mády G, Simonyi M. Conformation selectivity in the binding of diazepam and analogues to α1-acid glycoprotein. Bioorg Med Chem 2007; 15:4857-62. [PMID: 17507228 DOI: 10.1016/j.bmc.2007.04.060] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2006] [Revised: 04/19/2007] [Accepted: 04/27/2007] [Indexed: 11/30/2022]
Abstract
Diazepam, a 1,4-benzodiazepine lacking chiral centre, exists in an equimolar mixture of two chiral conformers. Induced circular dichroism spectra for the binding of diazepam and its 3,3-dimethyl substituted analogues to alpha1-acid glycoprotein (AGP) revealed that opposite to human serum albumin, AGP preferably binds the P-conformers. Accordingly, slightly favoured binding of (R)-enantiomers of 3-alkyl derivatives having P-conformation was found. In case of 3-acyloxy derivatives, however, AGP preferably binds the (S)-enantiomers. Studies with the separated genetic variants of AGP proved similar binding affinities, but markedly different conformation selectivities. For diazepam bound by the F1-S variant, a P/M selectivity of about 2 could be estimated.
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Affiliation(s)
- Ilona Fitos
- Department of Molecular Pharmacology, Institute of Biomolecular Chemistry Chemical Research Center, Hungarian Academy of Sciences, PO Box 17, H-1525 Budapest, Hungary.
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7
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Ascoli GA, Domenici E, Bertucci C. Drug binding to human serum albumin: abridged review of results obtained with high-performance liquid chromatography and circular dichroism. Chirality 2007; 18:667-79. [PMID: 16823814 DOI: 10.1002/chir.20301] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The drug binding to plasma and tissue proteins are fundamental factors in determining the overall pharmacological activity of a drug. Human serum albumin (HSA), together with alpha1-acid glycoprotein (AGP), are the most important plasma proteins, which act as drug carriers, with drug pharmacokinetic implications, resulting in important clinical impacts for drugs that have a relatively narrow therapeutic index. This review focuses on the combination of biochromatography and circular dichroism as an effective approach for the characterization of albumin binding sites and their enantioselectivity. Furthermore, their applications to the study of changes in the binding properties of the protein arising by the reversible or covalent binding of drugs are discussed, and examples of physiological relevance reported. Perspectives of these studies reside in supporting the development of new drugs, which require miniaturization to facilitate the screening of classes of compounds for their binding to the target protein, and a deeper characterization of the mechanisms involved in the molecular recognition processes.
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Affiliation(s)
- Giorgio A Ascoli
- Krasnow Institute for Advanced Study and Psychology Department, George Mason University, Fairfax, VA, USA
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8
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Fedurcová A, Lehotay J, Liptaj T, Prónayová N, Čižmárik J. HPLC Separation of Diazepam Conformers Coupled with Off‐Line NMR Experiment. J LIQ CHROMATOGR R T 2007. [DOI: 10.1080/10826070600598852] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Andrea Fedurcová
- a Department of Analytical Chemistry, Faculty of Chemical and Food Technology , Slovak University of Technology , Bratislava, Slovakia
| | - Jozef Lehotay
- a Department of Analytical Chemistry, Faculty of Chemical and Food Technology , Slovak University of Technology , Bratislava, Slovakia
| | - Tibor Liptaj
- b Central Laboratory, Faculty of Chemical and Food Technology , Slovak University of Technology , Bratislava, Slovakia
| | - Nad'a Prónayová
- b Central Laboratory, Faculty of Chemical and Food Technology , Slovak University of Technology , Bratislava, Slovakia
| | - Jozef Čižmárik
- c Department of Pharmaceutical Chemistry, Faculty of Pharmacy , Commenius University , Bratislava, Slovakia
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9
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Avdagić A, Lesac A, Majer Z, Hollòsi M, Šunjić V. Lipase-Catalyzed Acetylation of 3-Substituted 2,3-Dihydro-1H-1,4-benzodiazepin-2-ones: Effect of temperature and conformation on enantioselectivity and configuration. Helv Chim Acta 2004. [DOI: 10.1002/hlca.19980810558] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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10
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Baczek T, Kaliszan R. Quantitative structure/retention relationships in affinity chromatography. JOURNAL OF BIOCHEMICAL AND BIOPHYSICAL METHODS 2001; 49:83-98. [PMID: 11694274 DOI: 10.1016/s0165-022x(01)00190-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Affinity chromatography (AC) followed by quantitative structure/retention relationships (QSRR) analysis provides information on both the analytes and the macromolecules forming the stationary phases. QSRR equations derived for test series of analytes (often drugs) are interpreted in terms of structural requirements of the specific binding sites on macromolecules. Chromatographically demonstrated differences in analyte/macromolecule interactions may be relevant to molecular pharmacology and rational drug design. Multiple regression analysis of appropriately designed sets of affinity-chromatographic data may help increase the speed and efficiency of search as for new drugs and reduce the need for in vivo screening. Specific high-performance affinity-chromatographic separations can be optimized by rational selection of chiral columns, the characteristics of which are provided by QSRR.
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Affiliation(s)
- T Baczek
- Department of Biopharmaceutics and Pharmacodynamics, Medical University of Gdańsk, Gen. J. Hallera 107, 80-416 Gdańsk, Poland
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11
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Modulation of chromatographic performances of HSA-based HPLC column by reversible binding of lithocholic acid. Chromatographia 2001. [DOI: 10.1007/bf02491614] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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12
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Yoshida H, Kohno Y, Endo H, Ohmi N, Fukushima K, Suwa T, Hayashi M. Stereoselective disposition and chiral inversion of KE-298, a new antirheumatic drug, in rats. Chirality 2000; 9:22-8. [PMID: 9094199 DOI: 10.1002/(sici)1520-636x(1997)9:1<22::aid-chir5>3.0.co;2-i] [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: 02/04/2023]
Abstract
The present study was an attempt to elucidate the relationship between stereoselective pharmacokinetics and protein binding of KE-298 and its active metabolites, deacetyl-KE-298 (M-1) and S-methyl-KE-298 (M-2). Metabolic chiral inversion was also investigated. The levels of unchanged KE-298 in plasma after oral administration of (+)-(S)-KE-298 to rats were lower than those of (-)-(R)-KE-298, whereas the levels of M-1 and M-2 after administration of (+)-(S)-KE-298 were higher than after (-)-(R)-KE-298. In vitro, rat plasma protein binding of (+)-(S)-KE-298 was lower than that of (-)-(R)-KE-298. In contrast, the binding of (+)-(S)-M-1 and (+)-(S)-M-2 was higher than that of (-)-(R)-M-1 and (-)-(R)-M-2. Displacement studies revealed that the (+)-(S) and (-)-(R)- enantiomers of KE-298 and their metabolites bound to the warfarin binding site on rat serum albumin. These results suggested that the stereoselective plasma levels in KE-298 and its metabolites were closely related to enantiomeric differences in protein binding attributed to quantitative differences in binding to albumin rather than to the different binding sites. Unidirectional chiral inversion was detected after oral administration of either (-)-(R)-KE-298 or (-)-(R)-M-2 to rats both yielding (+)-(S)-M-2.
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Affiliation(s)
- H Yoshida
- Department of Drug Metabolism, Taisho Pharmaceutical Co., Ltd., Saitama, Japan
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13
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Abstract
Systematic ab initio calculations were performed to investigate the ring inversion process of various 1,4-diazepines including diazepam, N(1)-desmethyldiazepam, and 3-methyl-N(1)-desmethyldiazepam. The diazepine ring adopts a shape of a boat; owing to asymmetric substitution two such boats are possible in mirror image relation to each other. In the present study both structural and solvent effects were investigated on the energetics of ring inversion of nine diazepine derivatives. The calculated ring inversion barriers for diazepam (17.6 kcal/mol) and N(1)-desmethyldiazepam (10.9 kcal/mol) are in good agreement with the corresponding experimental data. In the cases of diazepam and N(1)-desmethyldiazepam, the calculated minimum energy path of the ring inversion is asymmetric contrary to the fact that the terminals (M and P conformers) are equienergetic.
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Affiliation(s)
- B Paizs
- Institute of Chemistry, Chemical Research Center, Hungarian Academy of Sciences, P.O. Box 17, 1525 Budapest, Hungary.
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14
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Abstract
1. Many drugs used to treat psychiatric disorders contain a chiral center or a center of unsaturation and are marketed as a mixture of the resultant enantiomers or geometric isomers, respectively. These enantiomers or geometric isomers may differ markedly with regard to their pharmacodynamic and/or pharmacokinetic properties. 2. Examples of the effects of chiral centers or geometric centers on such properties are given for drugs from the following classes: antidepressants (tricyclics, selective serotonin reuptake inhibitors, monoamine oxidase inhibitors, viloxazine, bupropion, trazodone, mianserin, venlaflaxine); benzodiazepines, zoplicone, and antipsychotics. 3. As described in this review, there are several notable examples of psychiatric drugs currently available where the individual enantiomers or geometric isomers differ considerably with regard to factors such as effects on amine transport systems, interactions with receptors and metabolizing enzymes, and clearance rates from the body. Indeed, relatively recent developments in analytical and preparative resolution of racemic and geometric drug mixtures and increased interest in developing new drugs which interact with specific targets, which have been described in detail at the molecular level, have resulted in increased emphasis on stereochemistry in drug development.
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Affiliation(s)
- R M Lane
- Pfizer Inc., New York, New York 10017-5755, USA
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15
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Kaliszan R. Retention data from affinity high-performance liquid chromatography in view of chemometrics. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1998; 715:229-44. [PMID: 9792513 DOI: 10.1016/s0378-4347(98)00175-3] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
A combination of affinity chromatography and chemometrics is demonstrated to provide information on drug analytes and on biomacromolecules forming stationary phases, which is of relevance to molecular pharmacology and to rational drug design. The approach can also be applied to elucidate the molecular mechanism of enantioseparation on natural biopolymer stationary phases. Affinity high-performance liquid chromatographic data, which were determined on silica-based human serum albumin, alpha1-acid glycoprotein, keratin, collagen, melanin and amylose tris(3,5-dimethylphenylcarbamate) stationary phases, are discussed. Quantitative structure-retention relationships (QSRRs) derived for test series of drug analytes are interpreted in terms of structural requirements of specific binding sites on biomacromolecules. A means to quantify the differences in drug-biomacromolecule binding among the members of analyte families is demonstrated based on hydrophobicity and structural descriptors from molecular modeling. Chemometric processing of appropriately designed sets of affinity chromatographic data may increase the speed and efficiency of a search for new drugs, providing at the same time a chance to reduce the number of in vivo screenings. It can also be of help in rational selection of chiral columns for specific analytical separations.
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Affiliation(s)
- R Kaliszan
- Medical University of Gdańsk, Department of Biopharmaceutics and Pharmacodynamics, Poland
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Ascoli GA, Bertucci C, Salvadori P. Ligand binding to a human serum albumin stationary phase: use of same-drug competition to discriminate pharmacologically relevant interactions. Biomed Chromatogr 1998; 12:248-54. [PMID: 9787894 DOI: 10.1002/(sici)1099-0801(199809/10)12:5<248::aid-bmc742>3.0.co;2-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A technique based on a human serum albumin (HSA) stationary phase high-pressure liquid chromatography (HPLC) has been successfully used for the past few years to characterize the interactions between HSA and new substrates. Immobilized HSA conserves the binding properties of the protein in solution, allowing fast and reliable analyses of binding interactions. Nevertheless, clear evidence that all binding mechanisms of HSA-HPLC are pharmacologically relevant is so far lacking. In particular, non-stoichiometric interactions of injected ligands with stationary phase components such as silica and the amino acid medium (other than protein binding areas) might interfere with the correlation between chromatographic retention and HSA binding. Here we present a quantitative method to distinguish between the molecular interactions of a ligand with binding areas of potential pharmacological interest and other, non-saturable binding mechanisms. Such a method, based on HPLC same-ligand displacement, is simple and reliable, as confirmed by in situ protein denaturation. Consequently, we were able to distinguish between different types of competitions detected in the co-binding of two drugs to HSA.
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Affiliation(s)
- G A Ascoli
- Centro Studio C.N.R. Macromolecole Stereordinate ed Otticamento Attive, Università di Pisa, Italy
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17
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Salvadori P, Bertucci C, Ascoli G, Uccello-Barretta G, Rossi E. Direct resolution, characterization, and stereospecific binding properties of an atropisomeric 1,4-benzodiazepine. Chirality 1997; 9:495-505. [PMID: 9329179 DOI: 10.1002/(sici)1520-636x(1997)9:5/6<495::aid-chir16>3.0.co;2-j] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The chromatographic resolution of 7-chloro-1,3-dihydro-1-(1,1-dimethylethyl)-5- (2-fluorophenyl)-2H-1,4-benzodiazepin-2-on (7), the 2'-fluoro, N1-tertbutyl analogue of diazepam, was attained on both analytical and preparative (mgs) scales, by using several chiral stationary phases (CSPs). The stereochemistry of this compound was characterized by means of 1H-NMR Nuclear Overhauser Effect (NOE) analysis. The single enantiomers of 7 were tested for their configuration and stereochemical stability by circular dichroism (CD), and their interaction with the central nervous system (CNS) benzodiazepine receptor was assayed, showing a significant difference in their binding affinities. Protein binding studies with human serum albumin (HSA, the main benzodiazepine carrier in human plasma) immobilized on a silica stationary phase revealed that HSA also preferentially binds one stereoisomer of 7. However, both on line CD detection and stereospecific interaction with other common drugs clearly demonstrated that the stereoselectivity of immobilized HSA for 7 is opposite to that for all the other studied benzodiazepines. In addition, HSA stereoselectivity for 7 is opposite to CNS receptor binding stereoselectivity for the same compound. Such HSA anomalous stereoselectivity for 7 was also confirmed in aqueous buffer solution by competitive displacement studies. Compared to other chiral 1,4-benzodiazepines, compound 7 thus shows several anomalous binding properties: HSA and the CNS receptor demonstrated opposite enantioselective discrimination; HSA has reversed enantioselectivity for compound 7; and HSA stereospecifically binds the low-affinity enantiomer.
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Affiliation(s)
- P Salvadori
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Italy
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18
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Abstract
Several benzodiazepines were enantioresolved on a new carbohydrate chiral stationary phase based on maltooligosaccharides. The role of organic modifier, ionic strength, pH and temperature are examined and the results are discussed. In general, selectivity and retention were found to decrease with increasing organic modifier concentration. The appearance of two peaks for diazepam suggests that the reported separations are based on separation of conformers and was supported using circular dichroism detection. Counterintuitively, resolution and enantioselectivity were found to improve with increasing temperatures.
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Affiliation(s)
- A M Stalcup
- Department of Chemistry, University of Hawaii-Manoa Honolulu 96822, USA
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19
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Simonyi M. The concept of chiral conformers and its significance in molecular pharmacology. ADVANCES IN DRUG RESEARCH 1997. [DOI: 10.1016/s0065-2490(97)80005-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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20
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Ascoli G, Bertucci C, Salvadori P. Stereospecific and competitive binding of drugs to human serum albumin: a difference circular dichroism approach. J Pharm Sci 1995; 84:737-41. [PMID: 7562415 DOI: 10.1002/jps.2600840615] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Simultaneous binding of two drugs to human serum albumin (HSA) was investigated by difference circular dichroism (delta CD) spectroscopy. Phenylbutazone and diazepam were chosen as specific markers for binding areas I (cumarines) and II (indoles), respectively, and their stereospecific interactions with protein were selectively characterized. Displacers were drugs known to specifically bind to areas I (salicylate) and II (racemic ibuprofen). The results indicate two different interaction mechanisms: a direct competition one (diazepam-ibuprofen and phenylbutazone-salicylate) and an indirect competition one (diazepam-salicylate and phenylbutazone-ibuprofen). The two major binding areas on HSA are distinct, but not independent, entities. Finally, the dissociation constants of marker ligands and competitors complexed to HSA were determined by quantitative analysis of CD data.
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Affiliation(s)
- G Ascoli
- Scuola Normale Superiore, Pisa, Italy
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21
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Vestemar V, Medic-Saric M, Rendic S. Binding of (+)- and (-)-isomers and racemate of etomoxir to human serum albumin and effect of stearic acid and stanozolol. J Pharm Sci 1994; 83:485-90. [PMID: 8046600 DOI: 10.1002/jps.2600830408] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Binding of (+)- and (-)-isomers and the racemate of sodium 2[6-(4-chlorophenoxy)-hexyl]-oxiran-2-carboxylate dihydrat (etomoxir) to the human serum albumin (HSA) was studied by the gel filtration method. The experimental results are presented graphically using the method of Scatchard. Measurements revealed the following data on the binding: (a) for either of the isomers there are two independent and nonequivalent classes of binding sites on the HSA molecule; (b) the binding constants calculated for both isomers were of the same order of magnitude (K1/n approximately 20 x 10(5) L.mol-1 for the concentration range 3.48-4.0 x 10(-5) mol.L-1, and K2/n approximately 2 x 10(5) L.mol-1 for the concentration range 4.28-10 x 10(-5) mol.L-1, for the high and low affinity binding sites, respectively); (c) statistically significant difference (p < or = 0.05) between the low affinity binding constant estimated for the (+)-isomer K2 = 1.9 +/- 0.1 x 10(5) L.mol-1) compared with the constants evaluated for the (-)-isomer and racemic etomoxir (2.6 +/- 0.1 and 2.9 +/- 0.2 x 10(5) L.mol-1, respectively); and (d) both isomers are bound into a high extent to the HSA molecule (i.e., at a ligand concentration of 3.48 x 10(-5) mol.L-1, the percent of binding was approximately 95% for the compound tested. When plotting the percent binding (% Cb) against the total concentration (Ctot), a statistically significant difference (p < or = 0.05) was obtained between the slope of the straight line for the (+)-isomer and those for other two compounds.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- V Vestemar
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy and Biochemistry, University of Zagreb, Croatia
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22
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Lévai A, Ott J, Snatzke G. Oxazepines and thiazepines, XXVIII Circular dichroism of optically active 2,3-dihydro-2-methyl-1,5-benzoxazepin-4(5H)-ones. MONATSHEFTE FUR CHEMIE 1993. [DOI: 10.1007/bf00808510] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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23
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Chosson E, Uzan S, Gimenez F, Wainer IW, Farinotti R. Influence of specific albumin ligand markers used as modifiers on the separation of benzodiazepine enantiomers by chiral liquid chromatography on a human serum albumin column. Chirality 1993; 5:71-7. [PMID: 8102067 DOI: 10.1002/chir.530050206] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Specific ligand markers for the various binding sites of human serum albumin (HSA) have been described in the literature. Some of these markers (medium chain fatty acids, warfarin, digoxin, and bilirubin) were used as mobile phase modifiers. Using a high performance liquid chromatographic (HPLC) column containing HSA as stationary phase, their influence was investigated on the separation in this phase of the enantiomers of three benzodiazepines (temazepam, oxazepam, and lorazepam). Displacement effects were observed with medium chain fatty acids. This influence was proportional to the chain length and to the concentration of acid. Allosteric cooperative effects were noted with digoxin for the three benzodiazepines. Both displacement and cooperative effects were observed with warfarin. Stereoselectivity was decreased for temazepam and oxazepam and increased for lorazepam.
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Affiliation(s)
- E Chosson
- Unité de Dosage de Médicaments, Hôpital Pitié Salpetriere, Paris, France
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24
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Stereoselectivity of the binding of drugs by blood plasma proteins (review). Pharm Chem J 1990. [DOI: 10.1007/bf00767020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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25
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Simonyi M, Maksay G, Kovács I, Tegyey Z, Párkányi L, Kálmán A, Ötvös L. Conformational recognition by central benzodiazepine receptors. Bioorg Chem 1990. [DOI: 10.1016/0045-2068(90)90010-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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26
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Fitos I, Visy J, Magyar A, Kajtár J, Simonyi M. Stereoselective effect of warfarin and bilirubin on the binding of 5-(o-chlorophenyl)-1,3-dihydro-3-methyl-7-nitro-2H-1,4-benzodiazepin-2- one enantiomers to human serum albumin. Chirality 1990; 2:161-6. [PMID: 1979230 DOI: 10.1002/chir.530020307] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The binding of the title benzodiazepine enantiomers and its modulation by warfarin and bilirubin were studied by chromatography on human serum albumin (HSA) immobilized on Sepharose 4B, and also by a combination of ultrafiltration and circular dichroism (UF-CD) methods. In the absence of warfarin and bilirubin the binding of the benzodiazepine was not stereoselective. (S)-Benzodiazepine and (S)-warfarin mutually increased the binding of each other, while the binding of (R)-benzodiazepine was preferentially enhanced on HSA saturated with bilirubin.
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Affiliation(s)
- I Fitos
- Central Research Institute for Chemistry, Hungarian Academy of Sciences, Budapest
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27
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Martens J, Bhushan R. Importance of enantiomeric purity and its control by thin-layer chromatography. J Pharm Biomed Anal 1990; 8:259-69. [PMID: 2094425 DOI: 10.1016/0731-7085(90)80035-n] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Methods for the direct resolution of enantiomers are important and are necessary for pharmaceutical and biomedical analysis, synthetic and mechanistic studies and various other fields. The present paper deals with the results of recent approaches, such as ligand exchange, ion exchange and steric interactions, providing direct resolution of enantiomers of a variety of compounds by thin-layer chromatography. General aspects of various methods for analysis of enantiomeric purity and resolution have been compared.
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Affiliation(s)
- J Martens
- Fachbereich Chemie, Universität Oldenburg, FRG
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Domenici E, Bertucci C, Salvadori P, Motellier S, Wainer IW. Immobilized serum albumin: rapid HPLC probe of stereoselective protein-binding interactions. Chirality 1990; 2:263-8. [PMID: 2083149 DOI: 10.1002/chir.530020412] [Citation(s) in RCA: 98] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A human serum albumin-based HPLC chiral stationary phase (HSA-CSP) has been examined as a tool to investigate binding of chiral drugs to HSA and drug-drug protein-binding interactions. Rac-oxazepam hemisuccinate (OXH) was used as a model compound and the chromatographic retention (k') of its enantiomers was determined after addition of displacers to the mobile phase. Compounds known to bind at the same site as OXH and at different sites were tested for their displacing capacities. Competitive binding interactions between the OXH enantiomers and displacers in the mobile phase were reflected by decreases in the k's of (R)- and (S)-OXH. The results indicate that retention on the HSA-CSP accurately reflects binding to native HSA and the technique can determine enantioselective and competitive binding interactions at specific sites on HSA. The HSA-CSP was also able to recognize separate binding areas for (S)- and (R)-OXH.
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Affiliation(s)
- E Domenici
- Dipartimento di Chimica e Chimica Industriale, Universita di Pisa, Italy
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29
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Bertucci C, Domenici E, Salvadori P. Stereochemical features of 1,4-benzodiazepin-2-ones bound to human serum albumin: difference CD and UV studies. Chirality 1990; 2:167-74. [PMID: 2252845 DOI: 10.1002/chir.530020308] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The stereochemistry of an achiral (Diazepam) and two chiral (3-methyl and 3-succinyloxy substituted) 1,4-benzodiazepin-2-ones interacting with human serum albumin (HSA) has been investigated by making use of difference absorption (UV) and circular dichroism (CD) spectroscopies. Evidence is obtained for a higher affinity with HSA for one of the two possible conformations of the seven-membered benzodiazepine ring. The red shift revealed by the absorption difference spectrum between the free and the bound drug accounts for the CD difference spectra observed.
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Affiliation(s)
- C Bertucci
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Italy
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30
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Oxazepines and thiazepines, XX: CD-spectra of optically active 2-phenyl-2,3-dihydro-1,5-benzothiazepin-4(5H)-ones and related 3-phenylthio-3-phenyl-propionic acid derivatives, and X-ray diffraction of one phenylethylamide. MONATSHEFTE FUR CHEMIE 1989. [DOI: 10.1007/bf00808769] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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31
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Coutts RT, Baker GB. Implications of chirality and geometric isomerism in some psychoactive drugs and their metabolites. Chirality 1989; 1:99-120. [PMID: 2701850 DOI: 10.1002/chir.530010204] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Many drugs contain a chiral centre, or such a centre is introduced during metabolism of the drug in man and in animals. If a single chiral centre is present, the drug will normally exist as a mixture of two enantiomers, of which one may have quite different pharmacologic and/or toxic effects than the other. Chiral drugs that are used in psychiatry, and some other pharmacologically related drugs are identified, and the implications of the presence of one or two chiral centres in these drugs are discussed. Differences in pharmacologic properties of drug and metabolite enantiomers are identified and discussed. Also reviewed are the properties of some drugs used in psychiatry that both are chiral and display geometric isomerism.
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Affiliation(s)
- R T Coutts
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Canada
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32
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Abstract
1. Various drugs of neuropsychopharmacological importance contain one or more chiral centres, or centres of asymmetry are introduced during drug metabolism. 2. A drug or drug metabolite with one asymmetric centre exists in two enantiomeric forms, of which usually only one possesses the desired pharmacological activity. The other enantiomer may be inert, or possess an undesired activity. 3. In certain circumstances it is appropriate to administer the racemic drug (mixture of enantiomers), while on other occasions only the pure enantiomer which possesses the desired activity should be given. 4. Drugs employed in psychiatry that contain centres of asymmetry, or are metabolized to pharmacologically active chiral products are identified and implications of chirality are discussed.
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Affiliation(s)
- R T Coutts
- PMHAC Research Unit, Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Canada
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Abstract
Many drugs have one or more asymmetric centers and are administered as a racemate containing an equal mixture of enantiomers with different pharmacologic properties, routes, and rates of disposition in humans. For example, S-warfarin is more potent than R-warfarin, and is metabolized by different pathways. The S-enantiomer is primarily oxidized, and the R-enantiomer is metabolized by both oxidation and reduction. Nevertheless, because of the difficulty in separating and analyzing individual enantiomers, most pharmacokinetic and pharmacodynamic studies on drugs have been performed without considering the stereochemical factors. This is unfortunate, because a nonstereoselective approach to the study of chiral drugs precludes insight into potential valuable information that may be relevant to drug development and evaluation. On the other hand, when the pharmacologic properties (including activity, disposition, and interaction with the other enantiomer) of enantiomers have been defined, manipulation of the enantiomeric ratio or use of the pure enantiomer can be pursued to optimize therapeutic efficacy.
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Affiliation(s)
- Y W Lam
- Department of Pharmacology, University of Texas Health Science Center, San Antonio 78284-7765
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Puzicha G, L�vai A, Szil�gyi L. Oxazepines and thiazepines. XIX Synthesis of optically active 2,3-dihydro-1,5-benzothiazepin-4(5H)-ones. MONATSHEFTE FUR CHEMIE 1988. [DOI: 10.1007/bf00810103] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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35
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Fitos I, Simonyi M, Tegyey Z, Kajtár M, Otvös L. Binding of 3-alkyl-1,4-benzodiazepin-2-one stereoisomers to human serum albumin. Arch Pharm (Weinheim) 1986; 319:744-9. [PMID: 3778156 DOI: 10.1002/ardp.19863190811] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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36
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Fitos I, Tegyey Z, Simonyi M, Sjöholm I, Larsson T, Lagercrantz C. Stereoselective binding of 3-acetoxy-, and 3-hydroxy-1,4-benzodiazepine-2-ones to human serum albumin. Selective allosteric interaction with warfarin enantiomers. Biochem Pharmacol 1986; 35:263-9. [PMID: 3942599 DOI: 10.1016/0006-2952(86)90524-1] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Stereoselective binding of oxazepam, lorazepam, temazepam and methyl lorazepam as well as of their acetates to human serum albumin was investigated by different techniques. The 2'-chlorine and the N(1)-methyl substitution exert opposite effects on the antipodes. Enantiomers of oxazepam acetate (OAc) and lorazepam acetate (LAc) displace diazepam. Allosteric interactions with warfarin were manifested by either mutually increased or decreased binding depending on the structure of benzodiazepine and on the configuration of both benzodiazepine and warfarin. The most remarkable effect could be observed in the simultaneous binding of (S)-lorazepam acetate and (S)-warfarin.
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Simonyi M, Fitos I, Visy J. Chirality of bioactive agents in protein binding storage and transport processes. Trends Pharmacol Sci 1986. [DOI: 10.1016/0165-6147(86)90276-2] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Simonyi M, Fitos I. Stereoselective binding of a 2,3-benzodiazepine to human serum albumin. Effect of conformation on tofizopam binding. Biochem Pharmacol 1983; 32:1917-20. [PMID: 6882467 DOI: 10.1016/0006-2952(83)90058-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The binding of Tofizopam enantiomers to human serum albumin has been investigated by ultrafiltration and affinity chromatography. In solution, Tofizopam molecules exist in two conformations which slowly interconvert into each other. Both conformers of (R)-Tofizopam have the same binding constant of 4.8 X 10(3) M-1. The binding of the (S)-enantiomer, however, depends on the conformation. The minor and major (S)-conformers were characterized by association constants of 2.3 X 10(3) and 15.1 X 10(3) M-1, respectively. Thus, the stereoselectivity of binding differs for the two conformations of the enantiomers. Kinetic parameters for the interconversion of conformations have been determined. Tofizopam displaces both bound diazepam and warfarin.
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Fitos I, Simonyi M, Tegyey Z, Otvös L, Kajtár J, Kajtár M. Resolution by affinity chromatography: stereoselective binding of racemic oxazepam esters to human serum albumin. J Chromatogr A 1983; 259:494-8. [PMID: 6863427 DOI: 10.1016/s0021-9673(01)88039-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Simonyi M, Fitos I, Tegyey Z, Otvös L. Stationary ultrafiltration: a radio-tracer technique for studying stereoselective binding of racemic ligands. Biochem Biophys Res Commun 1980; 97:1-7. [PMID: 7458928 DOI: 10.1016/s0006-291x(80)80125-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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43
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Konował A, Snatzke G, Alebić-Kolbah T, Kajfez F, Rendić S, Sunjić V. General approach to chiroptical characterization of binding of prochiral and chiral 1,4-benzodiazepin-2-ones to human serum albumin. Biochem Pharmacol 1979; 28:3109-13. [PMID: 518709 DOI: 10.1016/0006-2952(79)90620-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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