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Haouas A, Mtiraoui H, Bouzayani N, Ibrahim S, Marque S, Hajji M, Bel‐Hadj‐Tahar R, Msaddek M. Synthesis of New Chiral Triazoles Linked 1,5‐Benzodiazepine Conjugates via Copper‐Catalyzed 1,3‐Dipolar Cycloaddition Reaction. ChemistrySelect 2021. [DOI: 10.1002/slct.202004276] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Amel Haouas
- Department of Chemistry Faculty of Science and Arts Northern Border University Arar Saudi Arabia
| | - Hasan Mtiraoui
- Laboratory of Heterocyclic Chemistry Natural Products and Reactivity: L.H.C.N.P.R Faculty of Sciences of Monastir University of Monastir Avenue of the environment Monastir 5000 Tunisia
| | - Nadia Bouzayani
- Laboratory of Asymmetric Organic Synthesis and Homogeneous Catalysis UR 11ES56) University of Monastir Faculty of Sciences avenue of the environment Monastir 5000 Tunisia
| | - Sana Ibrahim
- Laboratory of Heterocyclic Chemistry Natural Products and Reactivity: L.H.C.N.P.R Faculty of Sciences of Monastir University of Monastir Avenue of the environment Monastir 5000 Tunisia
| | - Sylvain Marque
- Institut Lavoisier de Versailles Université de Versailles Saint-Quentin-en-Yvelines 45 avenue des Etats-Unis 78 035 Versailles Cedex France
| | - Melek Hajji
- Research Unit: Electrochemistry Materials and Environment University of Kairouan 3100 Kairouan Tunisia
| | - Radhouane Bel‐Hadj‐Tahar
- King Khalid University College of Science Department of Chemistry 61413 Abha Saudi Arabia
- Photovoltaic Laboratory Research and Technology Center of Energy, Borj-Cedria Science and Technology Park, BP 95 2050 Hammem-Lif Tunisia
| | - Moncef Msaddek
- Laboratory of Heterocyclic Chemistry Natural Products and Reactivity: L.H.C.N.P.R Faculty of Sciences of Monastir University of Monastir Avenue of the environment Monastir 5000 Tunisia
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2
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Křemen F, Gazvoda M, Kafka S, Proisl K, Srholcová A, Klásek A, Urankar D, Košmrlj J. Synthesis of 1,4-Benzodiazepine-2,5-diones by Base Promoted Ring Expansion of 3-Aminoquinoline-2,4-diones. J Org Chem 2016; 82:715-722. [DOI: 10.1021/acs.joc.6b01497] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Filip Křemen
- Department
of Chemistry, Faculty of Technology, Tomas Bata University, Zlín 76272, Czech Republic
| | - Martin Gazvoda
- Faculty
of Chemistry and Chemical Technology, University of Ljubljana, Večna
pot 113, Ljubljana SI 1000, Slovenia
| | - Stanislav Kafka
- Department
of Chemistry, Faculty of Technology, Tomas Bata University, Zlín 76272, Czech Republic
| | - Karel Proisl
- Department
of Chemistry, Faculty of Technology, Tomas Bata University, Zlín 76272, Czech Republic
| | - Anna Srholcová
- Department
of Chemistry, Faculty of Technology, Tomas Bata University, Zlín 76272, Czech Republic
| | - Antonín Klásek
- Department
of Chemistry, Faculty of Technology, Tomas Bata University, Zlín 76272, Czech Republic
| | - Damijana Urankar
- Faculty
of Chemistry and Chemical Technology, University of Ljubljana, Večna
pot 113, Ljubljana SI 1000, Slovenia
| | - Janez Košmrlj
- Faculty
of Chemistry and Chemical Technology, University of Ljubljana, Večna
pot 113, Ljubljana SI 1000, Slovenia
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3
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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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4
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Menezes CMS, Rivera G, Alves MA, do Amaral DN, Thibaut JPB, Noël F, Barreiro EJ, Lima LM. Synthesis, biological evaluation, and structure-activity relationship of clonazepam, meclonazepam, and 1,4-benzodiazepine compounds with schistosomicidal activity. Chem Biol Drug Des 2012; 79:943-9. [PMID: 22321778 DOI: 10.1111/j.1747-0285.2012.01354.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The inherent morbidity and mortality caused by schistosomiasis is a serious public health problem in developing countries. Praziquantel is the only drug in therapeutic use, leading to a permanent risk of parasite resistance. In search for new schistosomicidal drugs, meclonazepam, the 3-methyl-derivative of clonazepam, is still considered an interesting lead-candidate because it has a proven schistosomicidal effect in humans but adverse effects on the central nervous system did not allow its clinical use. Herein, the synthesis, in vitro biological evaluation, and molecular modeling of clonazepam, meclonazepam, and analogues are reported to establish the first structure-activity relationship for schistosomicidal benzodiazepines. Our findings indicate that the amide moiety [N(1) H-C(2) (=O)] is the principal pharmacophoric unit of 1,4-benzodiazepine schistosomicidal compounds and that substitution on the amide nitrogen atom (N(1) position) is not tolerated.
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Affiliation(s)
- Carla M S Menezes
- Laboratório de Avaliação e Síntese de Substâncias Bioativas, Universidade Federal do Rio de Janeiro, P O Box 68024, 21944-971, Rio de Janeiro, RJ, Brazil
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5
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Hsu DC, Lam PCH, Slebodnick C, Carlier PR. Complete mapping of the stereochemical course of retentive deprotonation/alkylation of 1H-benzo[e][1,4]diazepin-2(3H)-ones. J Am Chem Soc 2009; 131:18168-76. [PMID: 19921816 DOI: 10.1021/ja907507j] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Enantiopure amino-acid derived 1H-benzo[e][1,4]diazepin-2(3H)-ones (BZDs) undergo highly retentive deprotonation/alkylation reactions. To confirm the role of stereolabile, axially chiral intermediates in these reactions and to determine the precise stereochemical course of deprotonation and alkylation, a new alanine-derived BZD (S)-1d was prepared. Because of slow diazepine ring inversion of the C3-alkylated derivatives of 1d, it proved possible to determine that electrophiles react at the concave face of the enolate derived from 1d. Furthermore, an enantiopure silyl enol ether derivative of (S)-1d was prepared and characterized by X-ray crystallography, confirming that deprotonation resulted in an (M)-configured axially chiral enolate. Activation parameters for diazepine ring inversion in the potassium enolate of 1d were determined experimentally and are well-matched by density functional calculations. Finally, the factors leading to concave-face alkylation of the enolate derived from 1d are analyzed based on calculated alkylation transition structures. Minimization of torsional effects at the BZD ring fusion and maximization of imine and amide resonance are proposed to favor concave-face alkylation.
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Affiliation(s)
- Danny C Hsu
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, USA
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6
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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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7
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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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8
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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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9
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Hu M, He P, Chen Y, Carr G, Guo J, Ye N. Method validation and determination of enantiomers and conformers in tofisopam drug substances and drug products by chiral high-performance liquid chromatography and kinetic and thermodynamic study of the interconversion of the conformers. J Chromatogr A 2006; 1129:47-53. [PMID: 16844130 DOI: 10.1016/j.chroma.2006.06.085] [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] [Received: 03/28/2006] [Revised: 06/14/2006] [Accepted: 06/21/2006] [Indexed: 11/20/2022]
Abstract
1-(3,4-Dimethoxyphenyl)-4-methyl-5-ethyl-7,8-dimethoxy-5H-2,3-benzodiazepine (tofisopam) contains one chiral center, so two enantiomeric forms exist. The ring system of tofisopam possesses two sterically stable boat structures, leading to two distinct conformers for each enantiomer. A method was developed for the separation of these enantiomers and conformers in the drug substances and drug products. Separation was achieved with a separation factor of at least 3.9 for any adjacent peaks. Validation of the method challenged linearity, limit of detection, limit of quantification, specificity, accuracy, repeatability, intermediate precision, robustness, and stability of standard and sample solutions, and all validation results met the acceptance criteria. A study of accuracy at 80%, 100%, and 120% levels gave recoveries of 100 +/- 1%. The RSD of six sample injections for repeatability was less than 0.5%. The detection limit of tofisopam enantiomer was as low as 0.12 microg/mL. The kinetics and thermodynamics of the interconversion of tofisopam conformers were also investigated, and the kinetic and equilibrium constants of the interconversion process were determined at 15 degrees C, 25 degrees C, and 35 degrees C.
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Affiliation(s)
- Mougang Hu
- Patheon Inc., Mississauga, Ont. L5N 7K9, Canada.
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10
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Zsila F, Matsunaga H, Bikádi Z, Haginaka J. Multiple ligand-binding properties of the lipocalin member chicken α1-acid glycoprotein studied by circular dichroism and electronic absorption spectroscopy: The essential role of the conserved tryptophan residue. Biochim Biophys Acta Gen Subj 2006; 1760:1248-73. [PMID: 16813999 DOI: 10.1016/j.bbagen.2006.04.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2006] [Revised: 04/19/2006] [Accepted: 04/25/2006] [Indexed: 11/28/2022]
Abstract
Multiple ligand-binding properties of the 30-kDa chicken alpha(1)-acid glycoprotein (cAGP), a member of the lipocalin protein family, were investigated for the first time by using circular dichroism (CD) and UV/Vis absorption spectroscopy methods. By measuring induced CD (ICD) spectra, high-affinity binding (K(a) approximately 10(5)-10(6) M(-1)) of several drugs, dyes and natural compounds to cAGP was demonstrated including antimalarial agents (quinacrine, primaquine), phenotiazines (chlorpromazine, methylene blue), propranolol, non-steroidal antiinflammatory drugs (ketoprofen, diclofenac), tamoxifen, diazepam, tacrine, dicoumarol, cationic dyes (auramine O, thioflavine T, ethidium bromide), benzo[a]pyrene, L-thyroxine, bile pigments (bilirubin, biliverdin), alkaloids (piperine, aristolochic acid), saturated and unsaturated fatty acids. Analysis of the extrinsic CD spectra with the study of the covalently modified protein and CD displacement experiments revealed that a single Trp26 residue of cAGP conserved in the whole lipocalin family is part of the binding site, and it is essentially involved in the ligand-binding process via pi-pi stacking interaction resulting in the appearance of strong induced CD bands due to the non-degenerate intermolecular exciton coupling between the pi-pi* transitions of the stacked indole ring-ligand chromophore. The finding that cAGP is able to accommodate a broad spectrum of ligands belonging to different chemical classes suggests that its core beta-barrel cavity is unusually wide containing overlapping sub-sites. Significance of these new data in understanding of the ligand-binding properties of other lipocalins, especially that of human AGP, and potential practical applications are briefly discussed. Overall, cAGP serves as a simple, ultimate model to extend our knowledge on ligand-binding properties of lipocalins and to study the role of tryptophan residues in molecular recognition processes.
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Affiliation(s)
- Ferenc Zsila
- Department of Molecular Pharmacology, Institute of Biomolecular Chemistry, Chemical Research Center, Budapest, P.O. Box 17, H-1525, Hungary.
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11
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Lam PCH, Carlier PR. Experimental and Computational Studies of Ring Inversion of 1,4-Benzodiazepin-2-ones: Implications for Memory of Chirality Transformations. J Org Chem 2005; 70:1530-8. [PMID: 15730270 DOI: 10.1021/jo048450n] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We recently reported the enantioselective syntheses of quaternary 1,4-benzodiazepin-2-ones via memory of chirality. The success of this method depends on formation of conformationally chiral enolates that racemize very slowly under the reaction conditions. As a prelude to undertaking experimental and computational studies on the racemization of these enolates, we have studied the ring-inversion process of the parent 1,4-benzodiazepin-2-ones. In this paper, we use dynamic and 2D-EXSY NMR to characterize inversion barriers. Using DFT calculations, we reproduce the experimental results with high accuracy (within 1-2 kcal/mol). Structural parameters obtained from DFT calculations provide valuable insights into the important effect of the N1 substituent on the ring-inversion barrier and shed light on the mechanism of the memory of chirality method. These measurements and calculations provide a foundation for future studies of benzodiazepine enolates and will be valuable in the design of new memory of chirality reactions.
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Affiliation(s)
- Polo C-H Lam
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, USA
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12
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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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13
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Carlier PR, Zhao H, DeGuzman J, Lam PCH. Enantioselective synthesis of "quaternary" 1,4-benzodiazepin-2-one scaffolds via memory of chirality. J Am Chem Soc 2003; 125:11482-3. [PMID: 13129335 DOI: 10.1021/ja0365781] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Glycine-derived 1,4-benzodiazepine-2-ones such as diazepam are chiral by virtue of the boat-shaped conformation of the diazepine ring and exist as a racemic mixture of conformational enantiomers. However, the presence of a chiral center at C-3 of the benzodiazepine perturbs this equilibrium and preferentially stabilizes one ring conformer. We report that N-i-Pr 1,4-benzodiazepine-2-ones derived from (S)-Ala and (S)-Phe can be deprotonated and alkylated in 86-99% ee, despite the fact that the original chiral center is destroyed in the deprotonation step. We attribute this highly enantioselective alkylation to the chiral memory of the benzodiazepine ring. This protocol provides easy access to the previously unexplored "quaternary" 1,4-benzodiazepine-2-ones.
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Affiliation(s)
- Paul R Carlier
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, USA.
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14
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Fitos I, Visy J, Simonyi M. Species-dependency in chiral-drug recognition of serum albumin studied by chromatographic methods. JOURNAL OF BIOCHEMICAL AND BIOPHYSICAL METHODS 2002; 54:71-84. [PMID: 12543492 DOI: 10.1016/s0165-022x(02)00131-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Stereoselective binding of benzodiazepine and coumarin drugs to serum albumin from human and six mammalian species were studied by chiral chromatographic techniques. The applied methods were affinity chromatography on the albumins immobilized on Sepharose 4B, high-performance liquid chromatography (HPLC) separation on columns based on human serum albumin (HSA) and bovine serum albumin (BSA), and chiral HPLC analysis of ultrafiltrates of solutions containing the racemic drug and the native protein. Substantial differences in preferred configurations and conformations were detected among the species. The binding stereoselectivity of the 2,3-benzodiazepine drug, tofisopam, in human, is opposite to that in all other species. In the binding of 1,4-benzodiazepines, dog albumin is very similar to HSA. Highly preferred binding of (S)-phenprocoumon was found with dog albumin.
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Affiliation(s)
- I Fitos
- Department of Molecular Pharmacology, Institute of Chemistry, Chemical Research Center, Hungarian Academy of Sciences, H-1525, PO Box 17, Budapest, Hungary.
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15
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Perillo MA, Arce A. Estimation of the binding affinity constants of soluble ligand-receptor complexes by a rapid filtration technique: [3H]-flunitrazepam-bovine serum albumin as an example. J Pharmacol Toxicol Methods 1996; 35:69-76. [PMID: 8729432 DOI: 10.1016/1056-8719(96)00002-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A method for determining the equilibrium dissociation constant (KA) of a soluble ligand (L) from a soluble receptor (A) in the presence of another solid phase receptor (R) for the same ligand was developed. The total and nonspecific binding of L to R was measured in the presence and in the absence of A. The separation of bound and free L was done by a rapid filtration technique so that only the complex RL, but not AL, was recovered. An apparent dissociation constant (KR,app) was calculated from the saturation curve obtained in the presence of A. The magnitude of KA could be determined from this KR,app and the value of the equilibrium dissociation constant of the complex R-L (KR) calculated from the saturation curve in the absence of A. The equality of the Bmax values obtained in the presence and in the absence of A assured the accuracy in the determination of KA so that the fulfillment of this condition could be used as an internal control. For the correct definition of nonspecific binding, the displacement agent (L1) should be used at concentrations within the range 10(2).KR < L1 < 10. K4. This fact constraints the applicability of the method to systems where KA/KR > 10(3). The highest sensitivity of the method can be attained when 0.33 < [At]/KA < 3. The equilibrium binding constant of [3H]-flunitrazepam to non-delipidized bovine serum albumin determined by the present approach (31 +/- 7 mumol/L) did not differ significantly from the literature.
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Affiliation(s)
- M A Perillo
- Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Argentina
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16
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Fitos I, Visy J, Simonyi M, Hermansson J. Separation of enantiomers of benzodiazepines on the Chiral-AGP column. J Chromatogr A 1995. [DOI: 10.1016/0021-9673(95)00444-r] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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17
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Bertucci C, Ascoli G, Uccello-Barretta G, Di Bari L, Salvadori P. The binding of 5-fluorouracil to native and modified human serum albumin: UV, CD, and 1H and 19F NMR investigation. J Pharm Biomed Anal 1995; 13:1087-93. [PMID: 8573632 DOI: 10.1016/0731-7085(95)01548-y] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
5-Fluorouracil (FU) is an important and widely used antineoplastic drug that is carried in the serum by plasma proteins. Protein binding studies of this drug to human serum albumin (HSA) have been carried out by several spectroscopic techniques. Difference circular dichroism and UV studies provided information on the class of binding sites involved in the interaction. In particular, displacement experiments showed that FU has at least one secondary binding site in the coumarin binding area, but does not interact with the benzodiazepine binding area. Binding was also investigated by difference 1H NMR and by measuring the increase in the 19F NMR signal of FU when bound to HSA. Finally, evidence was obtained that chemical acetylation of Lys199 results in a decreased apparent binding affinity constant (nK) for FU. Such a modification is induced under physiological conditions by aspirin.
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Affiliation(s)
- C Bertucci
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Italy
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18
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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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19
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Zandomeneghi M. Circular dichroism of ketoprofen complexed to serum albumins: conformational selection by the protein: a novel optical purity determination technique. Chirality 1995; 7:446-51. [PMID: 7577351 DOI: 10.1002/chir.530070610] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Complexation of 2-(3'-benzoylphenyl)propionic acid (ketoprofen), 1, to bovine serum albumin (BSA) results in an intense negative circular dichroism in the ketonic n-->pi* band of the benzoylphenyl moiety. This high CD contrasts with the weak CD of 1-enantiomers dissolved in common solvents. Furthermore, a number of chiral and achiral molecules containing the benzophenone moiety are easily complexed to BSA: all these complexes show an intense CD at the same transition. To account for the observed CD intensities of the above molecules, it appears that BSA complexation markedly shifts the equilibrium between strongly asymmetric, antipodic conformers. Dissymmetry of these conformers is connected to the instability of a structure with phenyl rings coplanar to the carbonyl chromophore, as also indicated by molecular mechanics calculations. The magnification of the Cotton effects of the 1-antipodes, due to the protein, can be used to measure the optical purity of 1-samples with excellent precision. In contrast with BSA, human SA is unable to recognize the chirality of 1-antipodes; oleic acid cocomplexation modifies this fact as well as other features of the binding.
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Affiliation(s)
- M Zandomeneghi
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Italy
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Bertucci C, Viegi A, Ascoli G, Salvadori P. Protein binding investigation by difference circular dichroism: native and acetylated human serum albumins. Chirality 1995; 7:57-61. [PMID: 7742173 DOI: 10.1002/chir.530070202] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A modified albumin was prepared by selective reaction of Lys199 with acetyl salicylic acid. Protein binding investigation was carried out on native and modified proteins by difference circular dichroism (delta CD). Acetylation of Lys199 reduces significantly the effects of the interaction between drugs in the stereoselective HSA binding at specific binding areas.
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Affiliation(s)
- C Bertucci
- Centro di Studio del C.N.R. per le Macromolecole Stereordinate ed Otticamente Attive, Università di Pisa, Italy
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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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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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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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24
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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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25
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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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26
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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. 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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29
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Decorte E, Toso R, Sega A, ?unji� V, Ru?i?-Toro? ?, Koji?-Prodi? B, Bresciani-Pahor N, Nardin G, Randaccio L. Chiral 1, 4-Benzodiazepin-2-one, template for enantioselective synthesis of ?-amino acids and their ?-deuterio congeners. Preliminary communication. Helv Chim Acta 1981. [DOI: 10.1002/hlca.19810640420] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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30
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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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