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Journal articles on the topic 'Enantiomere'

Author: Grafiati

Published: 4 June 2021

Last updated: 4 May 2024

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1

de Vries, J. X., U. Völker, and E. Weber. "Zur Enantioselektivität von Phenprocoumon beim Menschen*." Hämostaseologie 11, no. 02 (1991): 60–65. http://dx.doi.org/10.1055/s-0038-1660282.

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ZusammenfassungEnantiomere sind Moleküle, die sich wie Bild zu Spiegelbild verhalten; sie weisen fast identische chemische oder physikalische Eigenschaften auf, unterscheiden sich aber in ihren physiologischen Wirkungen. Es wird über das unterschiedliche pharmakokinetische Verhalten und die differierenden pharmakodynamischen Eigenschaften der Enantiomeren der oralen Antikoagulanzien Phenoprocoumon (PH), Warfarin (WA) und Acenocoumarol (AC) beim Menschen und über die daraus resultierenden therapeutischen Konsequenzen berichtet.Für eigene Untersuchungen zur enantioselektiven Elimination von PH b

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2

Saufi, Ahmad, Cosima B. I. von Heimendahl, A. Wilhelm Alfermann, and Elisabeth Fuss. "Stereochemistry of Lignans in Phaleria macrocarpa (Scheff.) Boerl." Zeitschrift für Naturforschung C 63, no. 1-2 (2008): 13–16. http://dx.doi.org/10.1515/znc-2008-1-203.

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Phaleria macrocarpa (Scheff.) Boerl., a member of the Thymelaeaceae, is traditionally used in Indonesia as medicinal plant against cancer. In this context, we isolated the lignans pinoresinol, lariciresinol and matairesinol from different parts of this plant. The enantiomeric composition of these lignans was determined by chiral column analysis. Pinoresinol and lariciresinol were mixtures of both enantiomers with (79 ± 4)% and (55 ± 6)% enantiomeric excess for the (−)-enantiomers, respectively, whereas matairesinol was found as pure (+)-enantiomer.

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3

Coles, Simon, David Davies, Michael Hursthouse, Serkan Yeşilot, Bünyemin Çoşut, and Adem Kılıç. "Absolute structure determination as a reference for the enantiomeric resolution of racemic mixtures of cyclophosphazenes via chiral high-performance liquid chromatography." Acta Crystallographica Section B Structural Science 65, no. 3 (2009): 355–62. http://dx.doi.org/10.1107/s0108768109006120.

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Reversed-phase chiral high-performance liquid chromatography (HPLC) is a potentially powerful technique for the enantiomeric resolution of racemic mixtures, although the elution order of enantiomers is only relative and it is necessary to fully characterize reference systems for this method to provide absolute configurational information. The enantiomeric resolution of a series of racemic di-spiro cyclotriphosphazene derivatives, N3P3 X 2[O(CH2)3NH]2 (X = Cl, Ph, SPh, NHPh, OPh) [(1)–(5), respectively] was carried out by reversed-phase chiral HPLC on a commercially available Pirkle-type chiral

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4

Wagener, H., D. Kalbhen, G. Berner, and U. Vögtle-Junkert. "Ibuprofen - Racemat und Enantiomere*." Aktuelle Rheumatologie 16, no. 02 (1991): 65–69. http://dx.doi.org/10.1055/s-2008-1047384.

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5

Knabe, Joachim. "Synthetische Enantiomere als Arzneistoffe." Pharmazie in Unserer Zeit 24, no. 6 (1995): 324–30. http://dx.doi.org/10.1002/pauz.19950240608.

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6

Blaschke, Gottfried, and Wolfgang F. Graute. "Enantiomere des konfigurationsstabilenC-Methylthalidomids." Liebigs Annalen der Chemie 1987, no. 7 (1987): 647–48. http://dx.doi.org/10.1002/jlac.198719870716.

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7

VS, PRAGADHEESH, ANJU YADAV, and CHANDAN S. CHANOTIYA. "Chiral differentiation of terpenoids in bergamot mint (Mentha citrata) cultivar Kiran: A non-menthol mint essential oil." Journal of Medicinal and Aromatic Plant Sciences 42, no. 2 (2020): 138–44. http://dx.doi.org/10.62029/jmaps.v42i2.vs.

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Mentha citrata, popularly known as bergamot mint,is one of the mint species which does not possess menthol, a terpenoid chemical constituent that gives the name Mentha to the genus. CSIR-CIMAP has developed a cultivar cv. Kiran by induced mutagenesis. Gas chromatographic (GC) analysis of the essential oil of this cultivar shows linalool (44.9 %) and linalyl acetate (28.7%) as the major constituents. Further, the enantioselective GC analysis of the essential oil to determine the enantiomeric ratio of linalool and linalyl acetate indicate that (R)-(-)-linalool is in 78.8% excess over its enantio

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8

Zhou, Juan, Qiao Chen, Li-lan Wang, Yong-hua Wang, and Ying-zi Fu. "Chiral Discrimination of Tryptophan Enantiomers via (1R, 2R)-2-Amino-1, 2-Diphenyl Ethanol Modified Interface." International Journal of Electrochemistry 2011 (2011): 1–6. http://dx.doi.org/10.4061/2011/502364.

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The paper reported that a simple chiral selective interface constructed by (1R, 2R)-2-amino-1, 2-diphenyl ethanol had been developed to discriminate tryptophan enantiomers. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used for the characteristic analysis of the electrode. The results indicated that the interface showed stable and sensitive property to determine the tryptophan enantiomers. Moreover, it exhibited the better stereoselectivity for L-tryptophan than that for D-tryptophan. The discrimination characteristics of the chiral selective interface for discr

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9

Tok, Kenan Can, Mehmet Gumustas, Giorgi Jibuti, Halit Sinan Suzen, Sibel A. Ozkan, and Bezhan Chankvetadze. "The Effect of Enantiomer Elution Order on the Determination of Minor Enantiomeric Impurity in Ketoprofen and Enantiomeric Purity Evaluation of Commercially Available Dexketoprofen Formulations." Molecules 25, no. 24 (2020): 5865. http://dx.doi.org/10.3390/molecules25245865.

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In a recent study, opposite enantiomer elution order was observed for ketoprofen enantiomers on two amylose-phenylcarbamate-based chiral columns with the same chemical composition of the chiral selector but in one case with coated while in the other with an immobilized chiral selector. In the present study, the influence of this uncommon effect on method validation parameters for the determination of minor enantiomeric impurity in dexketoprofen was studied. The validated methods with two alternative elution orders for enantiomers were applied for the evaluation of enantiomeric impurity in six

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10

Hocking, Martin B., and Aga Z.-Q. Khan. "Chromatographic enantiomer separation and circular dichroism (CD) spectra of three 4-endosubstituted-3,6-diphenyl-3,6-phenylphosphorylcyclohexenes." Canadian Journal of Chemistry 85, no. 9 (2007): 600–602. http://dx.doi.org/10.1139/v07-088.

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Three enantiomeric pairs of Diels–Alder adducts of 2,5-diphenylphosphole-1-oxide have been resolved by elution of each of the enantiomers with 95% ethanol from a swollen microcrystalline triacetylcellulose stationary phase. The degree of separation achieved in each case was confirmed by comparing the absorbance maximum of the UV spectrum of each separated enantiomer with that of a similar concentration of the relevant racemic mixture. The circular dichroism (CD) spectrum of each of the separated enantiomers was recorded, and spectral parameters are listed.Key words: enantiomer separations, thr

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11

Dutta, Soham, and Andrew J. Gellman. "2D Ising Model for Enantiomer Adsorption on Achiral Surfaces: L- and D-Aspartic Acid on Cu(111)." Entropy 24, no. 4 (2022): 565. http://dx.doi.org/10.3390/e24040565.

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The 2D Ising model is well-formulated to address problems in adsorption thermodynamics. It is particularly well-suited to describing the adsorption isotherms predicting the surface enantiomeric excess, ees, observed during competitive co-adsorption of enantiomers onto achiral surfaces. Herein, we make the direct one-to-one correspondence between the 2D Ising model Hamiltonian and the Hamiltonian used to describe competitive enantiomer adsorption on achiral surfaces. We then demonstrate that adsorption from racemic mixtures of enantiomers and adsorption of prochiral molecules are directly analo

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12

Moberg, Christina. "KönnenC3-symmetrische Rezeptoren Enantiomere unterscheiden?" Angewandte Chemie 118, no. 29 (2006): 4838–40. http://dx.doi.org/10.1002/ange.200601214.

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13

Finefield, Jennifer M., David H. Sherman, Martin Kreitman, and Robert M. Williams. "Enantiomere Naturstoffe: Vorkommen und Biogenese." Angewandte Chemie 124, no. 20 (2012): 4886–920. http://dx.doi.org/10.1002/ange.201107204.

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14

Szabó-Szentjóbi, Hajnalka, Anna Márton, Dávid Pál, et al. "Synthesis, Fluorescence and NMR Spectroscopic Studies of a Novel Phosphinoxido-18-crown-6 Ether Containing an Anthracene Fluorophore Unit." Periodica Polytechnica Chemical Engineering 64, no. 1 (2019): 37–45. http://dx.doi.org/10.3311/ppch.14646.

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The synthesis of the (R,R) and (S,S) enantiomers of a new enantiopure monophospha-18-crown-6 ether (1), which contains an anthracene fluorophore unit and methyl groups at its stereogenic centers, was accomplished. The structure of one enantiomer ((S,S)-1) was studied using one-dimensional (1H, 13C{1H}, and 31P{1H}) and two-dimensional NMR spectra. Because (R,R)-1 and (S,S)-1 can act as new fluorescent chemosensors, we examined their enantiomeric differentiation abilities toward the enantiomers of protonated chiral primary amines and amino acid esters (PEA, 1-NEA, PGME, PAME) using UV-Vis and f

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15

Gładkowski, Witold, Aleksandra Włoch, Aleksandra Pawlak та ін. "Preparation of Enantiomeric β-(2′,5′-Dimethylphenyl)Bromolactones, Their Antiproliferative Activity and Effect on Biological Membranes". Molecules 23, № 11 (2018): 3035. http://dx.doi.org/10.3390/molecules23113035.

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Three novel enantiomeric pairs of bromolactones possesing a 2,5-dimethylphenyl substituent at the β-position of the lactone ring have been synthesized from corresponding enantiomeric (E)-3-(2′,5′-dimethylphenyl)hex-4-enoic acids (4) by kinetically controlled bromolactonization with N-bromosuccinimide (NBS). γ-Bromo-δ-lactones (5) were isolated as the major products. Absolute configurations of stereogenic centers of γ-bromo-δ-lactones (5) were assigned based on X-ray analysis; configurations of cis δ-bromo-γ-lactones (6) and trans δ-bromo-γ-lactones (7) were determined based on mechanism of bro

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16

Costa, Ana Rita, Virgínia M. F. Gonçalves, Bruno B. Castro, et al. "Toxicity of the 3,4-Methylenedioxymethamphetamine and Its Enantiomers to Daphnia magna after Isolation by Semipreparative Chromatography." Molecules 28, no. 3 (2023): 1457. http://dx.doi.org/10.3390/molecules28031457.

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MDMA (3,4-methylenedioxymethamphetamine) is a chiral psychoactive recreational drug sold in illicit markets as racemate. Studies on the impact of MDMA on aquatic organisms are scarce. While enantioselectivity in toxicity in animals and humans has been reported, none is reported on aquatic organisms. This study aimed to investigate the ecotoxicological effects of MDMA and its enantiomers in Daphnia magna. For that, enantiomers (enantiomeric purity > 97%) were separated by liquid chromatography using a homemade semipreparative chiral column. Daphnids were exposed to three concentrations of (R

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17

León-González, María Eugenia, and Noelia Rosales-Conrado. "Enantioselective determination of ibuprofen residues by chiral liquid chromatography: a systematic study of enantiomeric transformation in surface water and sediments." Environmental Chemistry 13, no. 4 (2016): 656. http://dx.doi.org/10.1071/en15146.

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Environmental context Ibuprofen, a common anti-inflammatory drug and one of many pharmaceuticals sold as a mixture of enantiomers, has recently been found in river and surface waters. There are, however, few analytical methods able to separate and accurately measure ibuprofen enantiomers in environmental matrices. This study reports a method for quantifying ibuprofen enantiomers in sediments and surface water, and applies it to shed light on the degradation and fate of the enantiomers in aquatic systems. Abstract The enantioselective composition of ibuprofen in sediments in contact with surfac

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18

Wang, Peng, Donghui Liu, Xu Gu, Shuren Jiang, and Zhiqiang Zhou. "Quantitative Analysis of Three Chiral Pesticide Enantiomers by High-Performance Column Liquid Chromatography." Journal of AOAC INTERNATIONAL 91, no. 5 (2008): 1007–12. http://dx.doi.org/10.1093/jaoac/91.5.1007.

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Abstract Methods for the enantiomeric quantitative determination of 3 chiral pesticides, paclobutrazol, myclobutanil, and uniconazole, and their residues in soil and water are reported. An effective chiral high-performance liquid chromatographic (HPLC)-UV method using an amylose-tris(3,5-dimethylphenylcarbamate; AD) column was developed for resolving the enantiomers and quantitative determination. The enantiomers were identified by a circular dichroism detector. Validation involved complete resolution of each of the 2 enantiomers, plus determination of linearity, precision, and limit of detect

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19

Wu, Xiuli, Yange Zhang, Wenzhen Li, et al. "A Validated LC Method for the Enantiomeric Separation of EAI045 on Chiral Stationary Phase." Journal of Chromatographic Science 58, no. 6 (2020): 562–68. http://dx.doi.org/10.1093/chromsci/bmz125.

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Abstract A simple and accurate chiral liquid chromatographic method was developed for enantiomeric resolution and determination of 2-(5-fluoro-2-hydroxyphenyl)-2-(1-oxo-2,3-dihydro-1H-isoindol-2-yl)-N-(1,3-thiazol-2-yl)acetamide (EAI045). The enantiomers of EAI045 were baseline resolved on a Chiralpak AD-H (250 mm × 4.6 mm, 5 μm) column using a mobile phase system containing n-hexane: 2-propanol (75: 25 v/v) at a flow rate of 1 mL min−1 at 30°C. The eluted analytes were subsequently detected with an ultraviolet detector at 254 nm. The effects of organic modifiers and temperature on the enantio

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20

Kant, Ravi, Ramesh Babu Bodla, Rubina Bhutani, and Garima Kapoor. "Enantioselective Box Behenken Optimized HPLC-DAD Method for the Simultaneous Estimation of Alogliptin Enantiomorphs in Pharmaceutical For mulations and their Pharmacokinetic Study in Rat Plasma." Advanced Pharmaceutical Bulletin 9, no. 1 (2019): 147–58. http://dx.doi.org/10.15171/apb.2019.018.

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Purpose: A stereoselective high performance liquid chromatographic analytical method withphotodiode array detector was developed and validated as per the International Conferenceon Harmonization (ICH) guidelines for the determination of alogliptin (ALO) enantiomers informulations and rat plasma.Methods: Enantiomeric separation was performed on a Phenomenex Lux Cellulose-2 chiralcolumn. Box-Behnken design was used to identify the optimum conditions of the threeindependent variables for the desired output responses.Results: The HPLC peaks of ALO enantiomers and the internal standard pioglitazone

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21

Buchcic-Szychowska, Aleksandra, Stanisław Leśniak, and Michał Rachwalski. "Chiral Aziridine Phosphines as Highly Effective Promoters of Asymmetric Rauhut–Currier Reaction." Symmetry 14, no. 8 (2022): 1631. http://dx.doi.org/10.3390/sym14081631.

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A series of chiral enantiomerically pure aziridines containing a phosphine moiety were synthesized and successfully applied as organocatalysts in asymmetric intramolecular Rauhut–Currier reactions of p-quinone derivatives. The desired chiral phenols were achieved in high chemical yields and with satisfactory values of enantiomeric excess (up to 98% ee, in some cases). The stereochemical course of the title reaction may be controlled by the use of an appropriate enantiomer of the catalyst. The individual enantiomers of the organocatalyst led to the formation of specific enantiomers of the chira

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22

Yang, S. K., M. Mushtaq, H. B. Weems, D. W. Miller, and P. P. Fu. "Stereoselective formation and hydration of 12-methylbenz[a]anthracene 5,6-epoxide enantiomers by rat liver microsomal enzymes." Biochemical Journal 245, no. 1 (1987): 191–204. http://dx.doi.org/10.1042/bj2450191.

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The K-region trans-5,6-dihydrodiols formed in the metabolism of 12-methylbenz[a]anthracene (12-MBA) by liver microsomal preparations from untreated, phenobarbital-treated and 3-methylcholanthrene-treated male Sprague-Dawley rats were found by chiral stationary-phase h.p.l.c. (c.s.p.-h.p.l.c.) analyses to contain (5S,6S)/(5R,6R) enantiomer ratios of 93:7, 88:12 and 97:3 respectively. The absolute stereochemistry of a 12-MBA trans-5,6-dihydrodiol enantiomer was elucidated by the exciton-chirality c.d. method. The 5,6-epoxides formed in the metabolism of 12-MBA by liver microsomal preparations fr

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23

Saksone, Lana, and Arnim Quante. "Enantiomere und Metaboliten in der Psychopharmakologie." DNP – Die Neurologie & Psychiatrie 24, no. 1 (2023): 40–47. http://dx.doi.org/10.1007/s15202-022-5591-3.

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24

Schurig, Volker. "Enantiomere auf Mars, Monden und Kometen." Nachrichten aus der Chemie 63, no. 6 (2015): 660–64. http://dx.doi.org/10.1002/nadc.201590220.

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25

Blaschke, Gottfried, Bernd Fröhlingsdorf, Karl-Hans Dee, Klaus Opitz, and Ulrich Hartig. "Nefopam-Enantiomere: Isolierung und antinocizeptive Wirkung." Archiv der Pharmazie 320, no. 4 (1987): 341–47. http://dx.doi.org/10.1002/ardp.19873200412.

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26

Antonsen, Simen, Erling B. Monsen, Kirill Ovchinnikov, et al. "Synthesis of the Enantiomers of Thioridazine." SynOpen 04, no. 01 (2020): 12–16. http://dx.doi.org/10.1055/s-0039-1690834.

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Thioridazine, a well-known antipsychotic drug, has shown promising effects on several bacterial strains (including Mycobacterium tuberculosis and methicillin-resistant Staphylococcus aureus). Suppressive effects towards selected cancer cell-lines have also been reported. However, due to adverse effects, the compound is no longer in use for the primary indication. More recent research has demonstrated that these side effects are limited to one of the two enantiomers, (+)-thioridazine. The question arises to whether the beneficial effects of thioridazine are limited to one enantiomer, or if (–)-

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27

Almeida, Ana Sofia, Bárbara Silva, João Pedro Silva, José Augusto Pereira, Fernando Remião, and Carla Fernandes. "Semi-Preparative Separation, Absolute Configuration, Stereochemical Stability and Effects on Human Neuronal Cells of MDPV Enantiomers." Molecules 28, no. 5 (2023): 2121. http://dx.doi.org/10.3390/molecules28052121.

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Synthetic cathinones, such as 3,4-methylenedioxypyrovalerone (MDPV), are widely abused due to their psychostimulant effects. As they are chiral molecules, studies of their stereochemical stability (racemization can occur in certain temperatures and acidic/basic environments) and of their biological and/or toxicity effects (enantiomers might display different properties) are of great relevance. In this study, the liquid chromatography (LC) semi-preparative enantioresolution of MDPV was optimized to collect both enantiomers with high recovery rates and enantiomeric ratio (e.r.) values. The absol

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28

Červinka, Otakar, and Vladimír Stružka. "Preparation of both enantiomers of (1R*, 2S*)-1-cyclohexyl-1,2-propanediol from the commercial Neuberg's ketol." Collection of Czechoslovak Chemical Communications 55, no. 11 (1990): 2685–91. http://dx.doi.org/10.1135/cccc19902685.

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Both the optically pure enantiomers of (1R*, 2S*)-1-cyclohexyl-1,2-propanediol (II) were prepared from commercial (R)-(-)-1-phenyl-1-hydroxy-2-propanone (I; Neuberg's ketol). (1R, 2S)-(+)-1-Cyclohexyl-1,2-propanediol ((+)-II) was obtained in 19% total yield, its (1S, 2R)-enantiomer ((-)-II) in 8% yield. Both diols, as well as their precursors, enantiomeric (1R*, 2S*)-1-phenyl-1,2-propanediols (IIIa), are suitable chiral synthons.

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29

Song, Mei, Claudio Fuentes, and Elizabeth Tomasino. "Chemo-diversity of chiral monoterpenes in different styles of Riesling wine from different regions." OENO One 56, no. 3 (2022): 155–65. http://dx.doi.org/10.20870/oeno-one.2022.56.3.4834.

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Monoterpenes are important characteristic compounds for aromatic white wines, including Riesling, but their enantiomer composition has been little explored in wine. Enantiomers can differ depending on region and style, as they are sensitive to environmental factors, and thus could be used for wine authentication. Thirteen monoterpene isomers were quantified by HS-SPME-MDGC-MS in fifty-four commercial Riesling wines from three wine styles (dry, medium dry and medium sweet) and four well-established wine-growing regions in Germany, France (Alsace) and the USA (New York and Oregon). Significant d

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30

Gandhi, Karan, Umang Shah, and Sandip Patel. "Drug Stereochemistry: A Prodigy For Pharmacology and Drug Development." Current Drug Discovery Technologies 17, no. 5 (2020): 565–73. http://dx.doi.org/10.2174/1570163816666190502101803.

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Stereochemistry has evinced the importance of many chiral drugs with respect to drug designing and development. A literature review was conducted for several chiral drugs involving pharmacokinetic and pharmacodynamic parameters of their enantiomers along with their uses in certain diseased conditions. This article mainly includes the pharmacological profile review of some chiral drugs and the aspects due to which the single enantiomer is of importance as compared to the racemic mixture of the drug. This was achieved by moderating the side effects or toxic effects; or by the potentiated activit

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31

Knabe, Joachim, and Joachim Biwersi. "Racemate und Enantiomere von 5,5-disubstituierten Hexahydropyrimidinen." Archiv der Pharmazie 327, no. 1 (1994): 31–32. http://dx.doi.org/10.1002/ardp.19943270106.

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32

Harman, Christine A., Melissa V. Turman, Kevin R. Kozak, Lawrence J. Marnett, William L. Smith та R. Michael Garavito. "Structural Basis of Enantioselective Inhibition of Cyclooxygenase-1 by S-α-Substituted Indomethacin Ethanolamides". Journal of Biological Chemistry 282, № 38 (2007): 28096–105. http://dx.doi.org/10.1074/jbc.m701335200.

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The modification of the nonselective nonsteroidal anti-inflammatory drug, indomethacin, by amidation presents a promising strategy for designing novel cyclooxygenase (COX)-2-selective inhibitors. A series of α-substituted indomethacin ethanolamides, which exist as R/S-enantiomeric pairs, provides a means to study the impact of stereochemistry on COX inhibition. Comparative studies revealed that the R- and S-enantiomers of the α-substituted analogs inhibit COX-2 with almost equal efficacy, whereas COX-1 is selectively inhibited by the S-enantiomers. Mutagenesis studies have not been able to ide

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33

Williams, J., N. Yassaa, S. Bartenbach, and J. Lelieveld. "Mirror image hydrocarbons from Tropical and Boreal forests." Atmospheric Chemistry and Physics Discussions 6, no. 5 (2006): 9583–602. http://dx.doi.org/10.5194/acpd-6-9583-2006.

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Abstract. Monoterpenes, emitted in large quantities by trees to attract pollinators and repel herbivores, can exist in mirror image forms called enantiomers. In this study such enantiomeric pairs have been measured in ambient air over extensive forest ecosystems in South America and northern Europe. For the dominant monoterpene, α-pinene, the (–)-form was measured in large excess over the (+)-form over the Tropical rainforest, whereas the reverse was observed over the Boreal forest. Interestingly, over the Tropical forest (–)-α-pinene did not correlate with its own enantiomer, but correlated w

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34

Williams, J., N. Yassaa, S. Bartenbach, and J. Lelieveld. "Mirror image hydrocarbons from Tropical and Boreal forests." Atmospheric Chemistry and Physics 7, no. 3 (2007): 973–80. http://dx.doi.org/10.5194/acp-7-973-2007.

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Abstract. Monoterpenes, emitted in large quantities by trees to attract pollinators and repel herbivores, can exist in mirror image forms called enantiomers. In this study such enantiomeric pairs have been measured in ambient air over extensive forest ecosystems in South America and northern Europe. For the dominant monoterpene, α-pinene, the (−)-form was measured in large excess over the (+)-form over the Tropical rainforest, whereas the reverse was observed over the Boreal forest. Interestingly, over the Tropical forest (−)-α-pinene did not correlate with its own enantiomer, but correlated w

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35

Gal, Joseph. "Single-Isomer Science: The Phenomenon and Its Terminology." CNS Spectrums 7, S1 (2002): 8–13. http://dx.doi.org/10.1017/s1092852900028546.

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ABSTRACTSingle-isomer drugs are of great importance in modern therapeutics. In this article, the basics of the underlying phenomenon are explained. Some molecules are chiral, ie, their mirror image is not superposable on the original. The most common element producing molecular chirality is a chiral center, typically a carbon atom carrying four different groups. The mirror-image molecules are termed enantiomers, but the less specific terms stereoisomers and isomers are also used. A substance consisting of only one of the two enantiomers is a single enantiomer or single isomer, and the 1:1 mixt

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36

Szabó, Zoltán-István, Beáta-Mária Benkő, Ágnes Bartalis-Fábián та ін. "Chiral Separation of Apremilast by Capillary Electrophoresis Using Succinyl-β-Cyclodextrin—Reversal of Enantiomer Elution Order by Cationic Capillary Coating". Molecules 28, № 8 (2023): 3310. http://dx.doi.org/10.3390/molecules28083310.

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A stereospecific capillary electrophoresis method was developed for the separation of the novel, antipsoriatic agent, apremilast (APR). Six anionic cyclodextrin (CD) derivatives were screened for their ability to discriminate between the uncharged enantiomers. Only succinyl-β-CD (Succ-β-CD) presented chiral interactions; however, the enantiomer migration order (EMO) was unfavorable, and the eutomer, S-APR, migrated faster. Despite the optimization of all possible parameters (pH, cyclodextrin concentration, temperature, and degree of substitution of CD), the method was unsuccessful for purity c

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Li, Zhi Wei, Xing Jia, Chun Mei Xu, Lei Liu, and De Cai Fu. "Chiral Separation of Amlodipine and its Enantiomer on a Molecularly Imprinted Polymer-Based Stationary Phase." Advanced Materials Research 706-708 (June 2013): 36–39. http://dx.doi.org/10.4028/www.scientific.net/amr.706-708.36.

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A new chiral stationary phase for amlodipine (3-ethyl 5-methyl-2 -[(-2-(aminoethoxymethyl)-4-(2-chlorophenyl)-1,4-dihydro-6-methyl-3,5-pyridinedicarboxylate) based on a molecularly imprinted polymer has been prepared by radiation polymerization method and used for chromatographic separation of the chiral enantiomers. The effects on the separation of mobile phase and flow rate were investigated, and the optimum conditions for HPLC were shown to be: mobile phase, chloroform; flow rate, 0.3 ml min-1; at room temperature. The results has shown that the amlodipine-imprinted polymer was capable of r

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Suraj Koorpet R, Akshay N, Nishanth G, Chandan R S, and Anand Kumar Tengli. "A Review on Chiral Columns/Stationary Phases for HPLC." International Journal of Research in Pharmaceutical Sciences 11, no. 2 (2020): 2466–80. http://dx.doi.org/10.26452/ijrps.v11i2.2240.

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The chiral separation of pharmaceutical molecules and their precursors is one of the important areas of application of HPLC in pharmaceutical analysis for obtaining enantiomerically pure drug. The latter procedures include the use of so-called chiral selectors to enantio-selectively recognise and isolate the enantiomer. The direct approaches, i.e. those which do not derivate the compound of interest before separation, are addressed in detail, since they are now the most common approaches. The role of stereochemistry in medicinal products is being given greater emphasis to medical practice. For

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Mostafa, Gamal A. E., Mohammed M. Hefnawy, and Abdulrahman El-Majed. "Separation and Determination of Clenbuterol by HPLC Using a Vancomycin Chiral Stationary Phase." Journal of AOAC INTERNATIONAL 92, no. 3 (2009): 824–29. http://dx.doi.org/10.1093/jaoac/92.3.824.

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Abstract Enantiomers of clenbuterol were separated by a new HPLC method on a chiral column. Enantiomeric resolution was achieved on a vancomycyin macrocyclic antibiotic chiral stationary phase known as chirobiotic V with UV detection at 247 nm. The polar ionic mobile phase consisting of methanoltriethylamineglacial acetic acid (100 + 0.05 + 0.025, v/v/v), was used at a flow rate of 1.0 mL/min. The method was validated for linearity, accuracy, precision, and robustness. Standard linear calibration curves were established for the R-() and S-(+) enantiomers over the range of 0.220 g/mL, and an av

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Knabe, Joachim, and Susanne Bender. "1,5-Benzodiazepine, 1. Mitt.: Racemate und Enantiomere von 3,3-Dialkyl-1,5-benzodiazepin-2,4-dionen: Synthese, Konfiguration und enantiomere Reinheit." Archiv der Pharmazie 326, no. 9 (1993): 551–58. http://dx.doi.org/10.1002/ardp.19933260911.

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Xu, Hao, Yifeng Dai, Shuyi Qiu, Baoguo Sun, and Xiangyong Zeng. "Distribution and Quantification of 1,2-Propylene Glycol Enantiomers in Baijiu." Foods 10, no. 12 (2021): 3039. http://dx.doi.org/10.3390/foods10123039.

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Enantiomers of 1,2-Propylene glycol (1,2-PG) were investigated in 64 commercial Chinese Baijiu including soy sauce aroma-type Baijiu (SSB), strong aroma-type Baijiu (STB), and light aroma-type Baijiu (LTB), via chiral gas chromatography (β-cyclodextrin). The natural enantiomeric distribution and concentration of 1,2-PG in various baijiu were studied to evaluate whether the distribution and content of the two isomers of 1,2-PG were correlated with the aroma type and storage year. The results showed that 1,2-PG has a high enantiomeric ratio and the (S)-configuration predominated in SSB. The aver

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Alembik, Marc C., and Irving W. Wainer. "Resolution and Analysis of Enantiomers of Amphetamines by Liquid Chromatography on a Chiral Stationary Phase: Collaborative Study." Journal of AOAC INTERNATIONAL 71, no. 3 (1988): 530–33. http://dx.doi.org/10.1093/jaoac/71.3.530.

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Abstract A rapid, accurate method for separating and determining the enantiomeric composition of amphetamine bulk drug and commercial preparations was developed and subjected to collaborative study. Amide derivatives of the amphetamine enantiomers are formed by using achiral 2-naphthoyl chloride. The resulting enantiomeric amides are then chromatographed on a commercially available chiral stationary phase with hexane-isopropyl alcohol-acetonitrile (97 + 3 + 0.5) mobile phase, with detection at 254 nm. Seven collaborators received bulk drug and commercial samples of amphetamine. The collaborato

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Bestmann, Hans Jürgen, and Wilfried Kellermann. "Synthese der natürlichenR-( - )Enantiomere dreier Galbanum-Harz Macrolide." Synthesis 1994, no. 12 (1994): 1257–61. http://dx.doi.org/10.1055/s-1994-25676.

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Ecker, Gerhard, Wilhelm Fleischhacker, and Christian R. Noe. "Ein Verfahren zur Synthese der Enantiomere von Propafenon." Archiv der Pharmazie 327, no. 11 (1994): 691–95. http://dx.doi.org/10.1002/ardp.19943271104.

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Hefnawy, Mohammed M., Mona M. Al-Shehri, Mohammed A. Abounassif, and Gamal A. E. Mostafa. "Enantioselective Quantification of Atenolol in Mouse Plasma by High Performance Liquid Chromatography Using a Chiral Stationary Phase: Application to a Pharmacokinetic Study." Journal of AOAC INTERNATIONAL 96, no. 5 (2013): 976–80. http://dx.doi.org/10.5740/jaoacint.11-191.

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Abstract Enantiomeric resolution of atenolol was achieved on the HPLC vancomycin macrocyclic antibiotic chiral stationary phase Chirobiotic V. The polar ionic mobile phase consisted of methanol–glacial acetic acid–triethylamine (100 + 0.025 + 0.75, v/v/v) at a flow rate of 0.8 mL/min. Fluorescence detection at 275/305 nm for excitation and emission, respectively, was used. Plasma samples were purified using SPE on Oasis HLB cartridges. The calibration curves in plasma were linear over the range of 5–400 ng/mL (r = 0.999) for each enantiomer with an LOD of 1.0 ng/mL. The proposed method was val

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Cook, J. I., S. Majeed, R. Ignell, J. A. Pickett, M. A. Birkett, and J. G. Logan. "Enantiomeric selectivity in behavioural and electrophysiological responses of Aedes aegypti and Culex quinquefasciatus mosquitoes." Bulletin of Entomological Research 101, no. 5 (2011): 541–50. http://dx.doi.org/10.1017/s0007485311000162.

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Abstract1-Octen-3-ol is a kairomone for many haematophagous insects including mosquitoes. Numerous studies have examined the effects of racemic 1-octen-3-ol; however, few studies have investigated the role of individual enantiomers in relation to mosquito attraction. In the present study, we investigated the behavioural and electrophysiological responses of two mosquito species, Aedes aegypti and Culex quinquefasciatus, to individual enantiomers and mixtures of 1-octen-3-ol, employing a laboratory Y-tube olfactometer and single sensillum recordings. The olfactory receptor neurons of both Ae. a

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Šaman, David, Martina Wimmerová та Zdeněk Wimmer. "Synthesis and Structure Assignment of 2-(4-Methoxybenzyl)cyclohexyl β-D-Galactopyranoside Stereoisomers". Collection of Czechoslovak Chemical Communications 71, № 8 (2006): 1186–98. http://dx.doi.org/10.1135/cccc20061186.

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Several promoters were used in the Koenigs-Knorr synthesis of the title alkyl β-D-galactopyranosides, both in their diastereoisomeric forms (5a/5b and 6a/6b), resulting from the synthesis performed with the respective racemic cis and trans isomers of 2-(4-methoxybenzyl)cyclohexan-1-ol, and in their enantiomerically pure forms 5a and 6a, starting only from the (1S,2S)- and (1S,2R)-enantiomers of 2-(4-methoxybenzyl)cyclohexan-1-ol. The aim of the study was to find convenient modification(s) of the Koenigs-Knorr synthesis of alkyl β-D-galactopyranosides from more hindered and more complex 2-subst

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Lankhorst, Peter, Jozef van Rijn, and Alexander Duchateau. "One-Dimensional 13C NMR Is a Simple and Highly Quantitative Method for Enantiodiscrimination." Molecules 23, no. 7 (2018): 1785. http://dx.doi.org/10.3390/molecules23071785.

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The discrimination of enantiomers of mandelonitrile by means of 1D 13C NMR and with the aid of the chiral solvating agent (S)-(+)-1-(9-anthryl)-2,2,2-trifluoroethanol (TFAE) is presented. 1H NMR fails for this specific compound because proton signals either overlap with the signals of the chiral solvating agent or do not show separation between the (S)-enantiomer and the (R)-enantiomer. The 13C NMR method is validated by preparing artificial mixtures of the (R)-enantiomer and the racemate, and it is shown that with only 4 mg of mandelonitrile a detection limit of the minor enantiomer of 0.5% i

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Langa, Ivan, Maria Elizabeth Tiritan, Diana Silva, and Cláudia Ribeiro. "Gas Chromatography Multiresidue Method for Enantiomeric Fraction Determination of Psychoactive Substances in Effluents and River Surface Waters." Chemosensors 9, no. 8 (2021): 224. http://dx.doi.org/10.3390/chemosensors9080224.

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Determination of psychoactive substances (PAS) and/or their metabolites in surface waters is crucial for environmental risk assessment, and disclosure of their enantiomeric fractions (EF) allows discrimination between consumption, direct disposal, and synthesis pathways. The aim of this study was to develop and validate an indirect method by gas chromatography coupled to mass spectrometry (GC–MS) based on derivatization using (R)-(−)-α-methoxy-α-(trifluoromethyl) phenylacetyl chloride as chiral derivatization reagent, for enantiomeric quantification of amphetamine (AMP), methamphetamine (MAMP)

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Mączka, Wanda, Katarzyna Wińska, Małgorzata Grabarczyk, and Renata Galek. "Plant-Mediated Enantioselective Transformation of Indan-1-One and Indan-1-ol." Catalysts 9, no. 10 (2019): 844. http://dx.doi.org/10.3390/catal9100844.

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The main purpose of this work was to discover the way to obtain pure enantiomers of indan-1-ol. The subject of the study was the ability of the plant enzyme system to reduce the carbonyl group of indan-1-one, as well as to oxidize the hydroxyl group of racemic indan-1-ol. Locally available fruit and vegetables were selected for stereoselective biotransformation. During the reduction, mainly alcohol of the S-(+)-configuration with a high enantiomeric excess (ee = 99%) was obtained. The opposite enantiomer was obtained in bioreduction with the apple and parsley. Racemic indan-1-ol was oxidized b

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