Abstract:
:Kinetic and equilibrium binding studies were performed on the interaction of warfarin enantiomers with human serum albumin (HSA) in the absence and presence of lorazepam acetate (LoAc) enantiomers. Binding kinetics were followed by recording changes in the fluorescence of warfarin upon binding to HSA using the stopped-flow technique. The binding of (R)-warfarin displayed an exponentially increasing fluorescence, satisfying the two-step mechanism reported previously for the racemate, i.e., a diffusion controlled pre-equilibrium is followed by a slower rearrangement of the complex. In the case of (S)-warfarin, the signal was biphasic: a fast fluorescence enhancement was followed by a slow decline. The different kinetic features indicate that the equilibrium conformations of the [(S)-warfarin-HSA] and [(R)-warfarin-HSA] complexes are achieved via different mechanisms. The phenomenon was seen in buffers of different pH and compositions. Equilibrium binding measurements indicated significantly lower molar intrinsic fluorescence for the (S)-warfarin complex, suggesting differences in the microenvironments of the bound enantiomers. In the presence of (S)-LoAc, the allosterically enhanced binding of (S)-warfarin manifested itself in accelerated relaxation kinetics. In accordance with the low molar intrinsic fluorescence determined for the stable ternary complex, the amplitude of the decline in fluorescence became larger.
journal_name
Chiralityjournal_title
Chiralityauthors
Fitos I,Visy J,Kardos Jdoi
10.1002/chir.10113subject
Has Abstractpub_date
2002-05-15 00:00:00pages
442-8issue
5eissn
0899-0042issn
1520-636Xjournal_volume
14pub_type
杂志文章相关文献
CHIRALITY文献大全abstract::The opening of ortho-substituted phenyl oxiranes by borohydrides is described both in aqueous and solid phases. Some remarkable differences in the regioselectivity and inversion of enantioselectivity of oxirane ring-opening are reported. The results obtained are compared with previous studies and have allowed some fac...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/(SICI)1520-636X(1999)11:7<541::AID-CHIR5>3
更新日期:1999-01-01 00:00:00
abstract::Separations of six dihydropyridine enantiomers on three commercially available cellulose-based chiral stationary phases (Chiralcel OD-RH, Chiralpak IB, and Chiralpak IC) were evaluated with high-performance liquid chromatography (HPLC). The best enantioseparation of the six chiral drugs was obtained with a Chiralpak I...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.22690
更新日期:2017-03-01 00:00:00
abstract::(+/-)-Pantoprazole ((+/-)-PAN), (+/-)-5-(difluoromethoxy)-2-[[3.4-dimethoxy-2-pyridinyl)methyl]sul finyl]- 1H-benzimidazole) is a chiral sulfoxide that is used clinically as a racemic mixture. The disposition kinetics of (+)-PAN and (-)-PAN given separately has been studied in rats. Serum levels of (+)- and (-)-PAN an...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/(SICI)1520-636X(1998)10:8<747::AID-CHIR5>3
更新日期:1998-01-01 00:00:00
abstract::The application of the Cartesian coordinate tensor transfer (CCT) technique for simulations of the IR absorption and vibrational circular dichroism (VCD) spectra of relatively large nucleic acid fragments is demonstrated on several case studies. The approach is based on direct ab initio calculations of atomic tensors,...
journal_title:Chirality
pub_type: 杂志文章,评审
doi:10.1002/chir.20872
更新日期:2010-01-01 00:00:00
abstract::Ion channels are pharmacologic receptors and as such exhibit stereoselective interactions with drugs. Ion channels are conformationally mobile transmembrane proteins existing in a number of open and closed states. Drug interactions with these different states may differ quantitatively and qualitatively. Stereoselectiv...
journal_title:Chirality
pub_type: 杂志文章,评审
doi:10.1002/(SICI)1520-636X(1996)8:1<35::AID-CHIR8>3.0
更新日期:1996-01-01 00:00:00
abstract::Rabeprazole is an effective proton pump inhibitor to treat acid-related diseases. To achieve the simultaneous determination of rabeprazole enantiomers in human plasma, a chiral LC-MS/MS method was developed and validated. Acetonitrile including 0.1% ammonium were used as protein precipitating agent. Analytes were sepa...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.23022
更新日期:2018-12-01 00:00:00
abstract::The concentration sensitivity of a racemic drug (chlorpheniramine maleate) in chiral capillary electrophoresis with electrospray ionization – mass spectrometric detection was improved ~500-fold via stacking. Enantiomeric separation was achieved through the use of a neutral chiral pseudostationary phase (2-hydroxpropyl...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.22257
更新日期:2014-11-01 00:00:00
abstract::A new enantiomerically pure P-chiral phosphine, (S)-cyclohexylmethyl- (1-naphthyl)phosphine (1) was prepared by phosphine-borane methodology and used in a mechanistic study of the Mitsunobu reaction. Enantiomerically enriched (S)-cyclo- hexylmethyl(1-naphtyl)phosphine oxide (8) is obtained if the reaction proceeds thr...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/(SICI)1520-636X(2000)12:5/6<346::AID-CHIR8
更新日期:2000-06-01 00:00:00
abstract::In order to cope with the increasing number of publications on the separation of enantiomers by chromatography on a chiral stationary phase, the graphical molecular database CHIRBASE was created. In the present state, the database package covers information (structural, bibliographic, and chromatographic data) on liqu...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.530050404
更新日期:1993-01-01 00:00:00
abstract::One- and two-color, mass selected R2PI spectra of the S(1)<--S(0) transitions in the bare (+)-(R)-1-phenyl-1-ethanol (E(R)) and its complexes with different solvent molecules (solv) (-)-(R)-2-butanol (B(R)) or (+)-(S)-2-butanol (B(S)) and (-)-(R)-2-butylamine (A(R)) or (+)-(S)-2-butylamine (A(S)), have been recorded a...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.10010
更新日期:2001-01-01 00:00:00
abstract::Diamino carboxylic acids have recently come to the attention of scientists working in the field of early life and its development. These are the monomers of a hypothetic early form of genetic material, the so-called Peptide Nucleic Acid (PNA) (Nielson et al., Proc Natl Acad Sci USA 2000;97:3868-3871). Since all biopol...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.20422
更新日期:2007-07-01 00:00:00
abstract::The direct asymmetric aldol reactions of equivalent molar amounts of aldehydes and ketones were carried out at -20 degrees C over alkaline Al(2)O(3) with 20 mol % of Pro-Trp as catalyst and 20 mol % of N-methylmorpholine or 1,4-diazabicyclo[2.2.2]octane as additive. After simple and environmentally friendly work-up, m...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.20783
更新日期:2010-06-01 00:00:00
abstract::Three chiral derivatives of the alkaloid sparteine (bispidines), characterized by the 3,7-diazabicyclo[3.3.1]nonane moiety, were designed as efficient ligands in a number of enantioselective reactions due to their metal coordination properties. A full evaluation of the 3D properties of the compounds was carried out, a...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.22586
更新日期:2016-04-01 00:00:00
abstract::Nine β-aminoketones were synthesized via Mannich reaction when benzaldehyde was condensed with some primary amines and acetophenone. The purified compounds were identified by using spectroscopic methods. The enantiomeric separation of these derivatives was carried out by high-performance liquid chromatography (HPLC) u...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.22434
更新日期:2015-05-01 00:00:00
abstract::We report here a sensitive method for the determination of the absolute configurations of primary amines using exciton-coupled circular dichroism (ECCD). The method works on a microgram scale by derivatization of chiral amines with quinoline chromophores. Complexation of the chiral ligands with metal ion fixes the geo...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.10158
更新日期:2003-02-01 00:00:00
abstract::The chiral discrimination ability of two recently prepared chiral stationary phases (CSP 1 and CSP 2), based on a leucine derived chiral selector, was tested for the enantiomers of dihydropyrimidone (DHPM) derivatives and compared with the commercially available Hyun-leucine CSP 3 and classical Pirkle-leucine CSP 4. B...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.20396
更新日期:2007-06-01 00:00:00
abstract::Herein, we present the solution-state NMR studies on dextromethorphan (1) under both isotropic and anisotropic conditions. From the measurement of 22 residual dipolar couplings using a stretched polystyrene gel (PS), we show that accurate and detailed structural information is readily determined including the relative...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.20703
更新日期:2010-01-01 00:00:00
abstract::The simultaneous disposition of fenoprofen enantiomers in synovial fluid and plasma was studied in 11 patients with arthritis and chronic knee effusions treated with a single oral dose of 600 mg rac-fenoprofen. A plasma sample and a synovial fluid sample were collected simultaneously from each patient up to 16 h after...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.20374
更新日期:2007-05-05 00:00:00
abstract::Bath salts, fumigations, cleaners and air fresheners, behind these terms substances are hidden, which count as "Legal Highs". These fancy names are used to pretend Legal Highs as harmless compounds, to circumvent legal regulations for marketing as well as to increase the sales. Besides classic illicit drugs of synthet...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.23135
更新日期:2020-01-01 00:00:00
abstract::Racemic N-methyl-N-(1-methyl-4-pyrrolidino-2-butynyl)acetamide (BM-5), a putative postsynaptic agonist and presynaptic antagonist at muscarinic receptors, was resolved into the enantiomers by a new method suitable for large scale preparation. The method involves a chemoselective N-debenzylation as the key step. The en...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.530040607
更新日期:1992-01-01 00:00:00
abstract::3alpha,12alpha-dihydroxy-5beta-cholan-24-oic acid (deoxycholic acid DCA) is able to discriminate between the R- and S-enantiomers of camphorquinone and endo-(+)-3-bromocamphor and select only the S-enantiomers from a racemic mixture. DCA forms novel well ordered 1:1 adducts with (1S)-(+)-camphorquinone and (1S)-endo-(...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.20561
更新日期:2008-07-01 00:00:00
abstract::In the presence of tridentate chiral ligand 4e, 99% e.e. value was obtained by asymmetric reduction of ethyl benzoylacetate with borane in toluene at 25 degrees C. Various ligands and reaction conditions were investigated to develop a reasonable mechanism that explains the experimental outcomes. ...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.20344
更新日期:2007-02-01 00:00:00
abstract::The initial step in the metabolism of dolasetron or MDL 73,147EF [(2 alpha, 6 alpha, 8 alpha, 9a beta)-octahydro-3-oxo-2,6-methano-2H- quinolizin-8-yl 1H-indol-3-carboxylate, monomethanesulfonate] is the reduction of the prochiral carbonyl group to give a chiral secondary alcohol "reduced dolasetron." An HPLC method, ...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.530070506
更新日期:1995-01-01 00:00:00
abstract::2-Alkenyl- and 2-vinyl-5-pyrimidyl alkanols are highly enantioselective asymmetric autocatalysts with significant amplification of enantiomeric excess in the enantioselective addition of diisopropylzinc to 2-alkenyl- and 2-vinylpyrimidine-5-carbaldehydes. Consecutive asymmetric autocatalysis starting from 7% ee increa...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.10068
更新日期:2002-02-01 00:00:00
abstract::The elusive epimerization process in the chiral butenolide moiety of Annonaceous acetogenins was examined under several sets of conditions commonly used for elimination leading to the alpha, beta-unsaturated lactone and the results provide practical guidance in choosing elimination conditions. ...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/(SICI)1520-636X(2000)12:3<127::AID-CHIR4>3
更新日期:2000-03-01 00:00:00
abstract::The aim of this work was to establish structure-reactivity relationships between chiral aggregates (micelles, vesicles, and "pseudo-micelles" of amphiphilic dendrimers) and asymmetric induction. In water, micelles or vesicles formed with sugar-headed surfactants gave less than 10% ee in the reduction of prochiral keto...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/1520-636X(2001)13:1<24::AID-CHIR5>3.0.CO;2
更新日期:2001-01-01 00:00:00
abstract::Glutathione (GSH) conjugation of the chiral compound 2-bromo-3-phenylpropionic acid (BPP) was studied in vitro and in the rat in vivo. GSH conjugation of BPP, catalyzed by a mixture of glutathione-S-transferases (GST's) from rat liver cytosol in vitro, was stereoselective: at a substrate concentration of 250 microM, (...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.530040702
更新日期:1992-01-01 00:00:00
abstract::Little is known about the stereochemistry of sulfation of chiral phenolic drugs. In this study we examined several in vitro approaches to this question, using (+)-, (-)-, or (+/-)-terbutaline as the substrate and the rat liver cytosol as the phenolsulfotransferase enzyme source. The cosubstrate PAPS was either generat...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.530010205
更新日期:1989-01-01 00:00:00
abstract::We present a new concept of synthesis for preparation of molecularly imprinted polymers using a functionalized initiator to replace the traditional functional monomer. Using propranolol as a model template, a carboxyl-functionalized radical initiator was demonstrated to lead to high-selectivity polymer particles prepa...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.23167
更新日期:2020-03-01 00:00:00
abstract::The resolution methods applying (-)-(4R,5R)-4,5-bis(diphenylhydroxymethyl)-2,2-dimethyldioxolane ("TADDOL"), (-)-(2R,3R)-α,α,α',α'-tetraphenyl-1,4-dioxaspiro[4.5]decan-2,3-dimethanol ("spiro-TADDOL"), as well as the acidic and neutral Ca(2+) salts of (-)-O,O'-dibenzoyl- and (-)-O,O'-di-p-toluoyl-(2R,3R)-tartaric acid ...
journal_title:Chirality
pub_type: 杂志文章
doi:10.1002/chir.22293
更新日期:2014-03-01 00:00:00