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Seog DJH, van Kien N, Ryoo JJ. Amino alcohol-derived chiral stationary phases. Chirality 2023; 35:739-752. [PMID: 37144722 DOI: 10.1002/chir.23574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 04/11/2023] [Accepted: 04/14/2023] [Indexed: 05/06/2023]
Abstract
An updated minireview of chiral stationary phases (CSPs) based on amino alcohols is presented. In this minireview, we focused on amino alcohols as starting materials in preparation of chiral catalysts for asymmetric organic synthesis and CSPs for chiral separations. Among the various CSPs, we summarized the important developments and applications of the amino alcohol-based Pirkle-type CSPs, ligand exchange CSPs, α-amino acid-derived amino alcohol CSPs, and symmetric CSPs from their first appearance to the present day to propose ideas for the development of new CSPs with improved performance.
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Affiliation(s)
- David Jin Han Seog
- Department of Chemistry Education, Kyungpook National University, Daegu, South Korea
| | - Nguyen van Kien
- Department of Chemistry Education, Kyungpook National University, Daegu, South Korea
| | - Jae Jeong Ryoo
- Department of Chemistry Education, Kyungpook National University, Daegu, South Korea
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2
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Tong S, Shen M, Cheng D, Zhang Y, Ito Y, Yan J. Chiral ligand exchange high-speed countercurrent chromatography: mechanism and application in enantioseparation of aromatic α-hydroxyl acids. J Chromatogr A 2014; 1360:110-8. [PMID: 25087742 PMCID: PMC4146671 DOI: 10.1016/j.chroma.2014.07.057] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 07/15/2014] [Accepted: 07/18/2014] [Indexed: 11/20/2022]
Abstract
This work concentrates on the separation mechanism and application of chiral ligand exchange high-speed countercurrent chromatography in enantioseparation of ten racemic aromatic α-hydroxyl acids, including mandelic acid, 2-chloromandelic acid, 4-methoxymandelic acid, 4-hydroxymandelic acid, α-methylmandelic acid, 4-hydroxy-3-methoxy-mandelic acid, 3-chloromandelic acid, 4-bromomandelic acid, α-cyclopentylmandelic acid and α-cyclohexylmandelic acid, in which five of the racemates were successfully enantioseparated by analytical apparatus with an optimized solvent system. The two-phase solvent system was composed of butanol-water (1:1, v/v) or hexane-n-butanol-water (0.5:0.5:1, v/v), to which N-n-dodecyl-l-proline was added in the organic phase as chiral ligand and cupric acetate was added in the aqueous phase as a transition metal ion. Various influence factors in high-speed countercurrent chromatography were optimized by enantioselective liquid-liquid extraction. The separation mechanism for chiral ligand exchange high-speed countercurrent chromatography was proposed based on the results of present studies. Successful enantioseparations of 72mg of mandelic acid, 76mg of 2-chloromandelic acid and 74mg of 4-methoxymandelic acid were achieved individually with high resolution by preparative high-speed countercurrent chromatography. The HPLC purity of all enantiomers was over 96% with the recovery in the range of 82-90% from the collected fractions.
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Affiliation(s)
- Shengqiang Tong
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310032, China; Laboratory of Bioseparation Technologies, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Mangmang Shen
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310032, China
| | - Dongping Cheng
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310032, China
| | - Yamei Zhang
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310032, China
| | - Yoichiro Ito
- Laboratory of Bioseparation Technologies, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Jizhong Yan
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310032, China.
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Schuur B, Verkuijl BJV, Minnaard AJ, de Vries JG, Heeres HJ, Feringa BL. Chiral separation by enantioselective liquid-liquid extraction. Org Biomol Chem 2010; 9:36-51. [PMID: 21107491 DOI: 10.1039/c0ob00610f] [Citation(s) in RCA: 156] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The literature on enantioselective liquid-liquid extraction (ELLE) spans more than half a century of research. Nonetheless, a comprehensive overview has not appeared during the past few decades. Enantioselective liquid-liquid extraction is a technology of interest for a wide range of chemists and chemical engineers in the fields of fine chemicals, pharmaceuticals, agrochemicals, fragrances and foods. In this review the principles and advances of resolution through enantioselective liquid-liquid extraction are discussed, starting with an introduction on the principles of enantioselective liquid-liquid extraction including host-guest chemistry, extraction and phase transfer mechanisms, and multistage liquid-liquid extraction processing. Then the literature on enantioselective liquid-liquid extraction systems is reviewed, structured on extractant classes. The following extractant classes are considered: crown ether based extractants, metal complexes and metalloids, extractants based on tartrates, and a final section with all other types of chiral extractants.
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Affiliation(s)
- Boelo Schuur
- University of Groningen, Chemical Engineering Department, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
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4
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Zhao JS, Yang SK. Red yeast catalyzed amination of olefinic bonds and synthesis of optically pure S-amino acids. CHINESE J CHEM 2010. [DOI: 10.1002/cjoc.19950130308] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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5
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Zou HF, Zhang YK, Lu PC. Separation mechanism of chiral compounds in chiral stationary phase liquid chromatography. CHINESE J CHEM 2010. [DOI: 10.1002/cjoc.19910090306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Pittler E, Grawatsch N, Paul D, Gübitz G, Schmid MG. Enantioseparation of amino acids, alpha-hydroxy acids, and dipeptides by ligand-exchange CEC using silica-based chiral stationary phases. Electrophoresis 2010; 30:2897-904. [PMID: 19655330 DOI: 10.1002/elps.200900092] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
This work deals with the application of silica-based ligand-exchange chiral stationary phases (CSPs) for the enantioseparation of underivatized amino acids, alpha-hydroxy acids, and dipeptides with packed CEC. Two different possibilities of preparing silica-based CSPs are presented. One phase contains L-4-hydroxyproline chemically bonded via a spacer to 3 mum silica material. The other approach makes use of N-decyl-L-4-hydroxyproline dynamically coated on a reversed-phase packed capillary. Dynamical coating of reversed-phase material represents a simple alternative to prepare CSP. A comparison of the chemically bonded phase with the dynamically coated CSP by means of resolution of complex-forming analytes is presented. The chemically bonded phase was found to be superior to the dynamically coated phase in terms of resolution of amino acids and dipeptides. However, the dynamically coated CSP was found to be especially suitable for the separation of alpha-hydroxy acids. Both techniques are applicable for enantiomer purity tests.
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Affiliation(s)
- Elfriede Pittler
- Institute of Pharmaceutical Sciences, Department of Pharmaceutical Chemistry, Karl-Franzens-University, Austria
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Charmotl D, Audebert R, Quivoron C. Retention Mechanism in Ligand exchange Chromatography of α-Amino Acids: Improved Resolution of Racemates with A New Mutildentate Polymeric Packing. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/01483918508074093] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Biernat JF, Konieczka P, Tarbet BJ, Bradshaw JS, Izatt RM. Complexing and Chelating Agents Immobilized on Silica Gel and Related Materials and Their Application for Sorption of Inorganic Species. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/03602549408006624] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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11
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Gübitz G, Pierer B, Wendelin W. Resolution of the enantiomers of drugs containing amino alcohol structure after derivatization with bromoacetic acid. Chirality 2004. [DOI: 10.1002/chir.530040512] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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12
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Madsen U, Bräuner-Osborne H, Frydenvang K, Hvene L, Johansen TN, Nielsen B, Sánchez C, Stensbøl TB, Bischoff F, Krogsgaard-Larsen P. Synthesis and pharmacology of 3-isoxazolol amino acids as selective antagonists at group I metabotropic glutamic acid receptors. J Med Chem 2001; 44:1051-9. [PMID: 11297452 DOI: 10.1021/jm000441t] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Using ibotenic acid (2) as a lead, two series of 3-isoxazolol amino acid ligands for (S)-glutamic acid (Glu, 1) receptors have been developed. Whereas analogues of (RS)-2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid [AMPA, (RS)-3] interact selectively with ionotropic Glu receptors (iGluRs), the few analogues of (RS)-2-amino-3-(3-hydroxy-5-isoxazolyl)propionic acid [HIBO, (RS)-4] so far known typically interact with iGluRs as well as metabotropic Glu receptors (mGluRs). We here report the synthesis and pharmacology of a series of 4-substituted analogues of HIBO. The hexyl analogue 9 was shown to be an antagonist at group I mGluRs. The effects of 9 were shown to reside exclusively in (S)-9 (K(b) = 30 microM at mGlu(1) and K(b) = 61 microM at mGlu(5)). The lower homologue of 9, compound 8, showed comparable effects at mGluRs, but 8 also was a weak agonist at the AMPA subtype of iGluRs. Like 9, the higher homologue, compound 10, did not interact with iGluRs, but 10 selectively antagonized mGlu(1) (K(b) = 160 microM) showing very weak antagonist effect at mGlu(5) (K(b) = 990 microM). The phenyl analogue 11 turned out to be an AMPA agonist and an antagonist at mGlu(1) and mGlu(5), and these effects were shown to originate in (S)-11 (EC(50) = 395 microM, K(b) = 86 and 90 microM, respectively). Compound 9, administered icv, but not sc, was shown to protect mice against convulsions induced by N-methyl-D-aspartic acid (NMDA). Compounds 9 and 11 were resolved using chiral HPLC, and the configurational assignments of the enantiomers were based on X-ray crystallographic analyses.
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Affiliation(s)
- U Madsen
- Centre for Drug Design and Transport, Department of Medicinal Chemistry, The Royal Danish School of Pharmacy, Universitetsparken 2, DK-2100 Copenhagen, Denmark.
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13
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Vogensen SB, Jensen HS, Stensbøl TB, Frydenvang K, Bang-Andersen B, Johansen TN, Egebjerg J, Krogsgaard-Larsen P. Resolution, configurational assignment, and enantiopharmacology of 2-amino-3-[3-hydroxy-5-(2-methyl-2H- tetrazol-5-yl)isoxazol-4-yl]propionic acid, a potent GluR3- and GluR4-preferring AMPA receptor agonist. Chirality 2000; 12:705-13. [PMID: 11054828 DOI: 10.1002/1520-636x(2000)12:10<705::aid-chir2>3.0.co;2-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We have previously shown that (RS)-2-amino-3-[3-hydroxy-5-(2-methyl-2H-tetrazol-5-yl)isoxazol -4-yl] propionic acid (2-Me-Tet-AMPA) is a selective agonist at (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA) receptors, markedly more potent than AMPA itself, whereas the isomeric compound 1-Me-Tet-AMPA is essentially inactive. We here report the enantiopharmacology of 2-Me-Tet-AMPA in radioligand binding and cortical wedge electrophysiological assay systems, and using cloned AMPA (GluR1-4) and kainic acid (KA) (GluR5, 6, and KA2) receptor subtypes expressed in Xenopus oocytes. 2-Me-Tet-AMPA was resolved using preparative chiral HPLC. Zwitterion (-)-2-Me-Tet-AMPA was assigned the (R)-configuration based on an X-ray crystallographic analysis supported by the elution order of (-)- and (+)-2-Me-Tet-AMPA using four different chiral HPLC columns and by circular dichroism spectra. None of the compounds tested showed detectable affinity for N-methyl-D-aspartic acid (NMDA) receptor sites, and (R)-2-Me-Tet-AMPA was essentially inactive in all of the test systems used. Whereas (S)-2-Me-Tet-AMPA showed low affinity (IC(50) = 11 microM) in the [(3)H]KA binding assay, it was significantly more potent (IC(50) = 0.009 microM) than AMPA (IC(50) = 0.039 microM) in the [(3)H]AMPA binding assay, and in agreement with these findings, (S)-2-Me-Tet-AMPA (EC(50) = 0.11 microM) was markedly more potent than AMPA (EC(50) = 3.5 microM) in the electrophysiological cortical wedge model. In contrast to AMPA, which showed comparable potencies (EC(50) = 1.3-3.5 microM) at receptors formed by the AMPA receptor subunits (GluR1-4) in Xenopus oocytes, more potent effects and a substantially higher degree of subunit selectivity were observed for (S)-2-Me-Tet-AMPA: GluR1o (EC(50) = 0.16 microM), GluR1o/GluR2i (EC(50) = 0.12 microM), GluR3o (EC(50) = 0.014 microM) and GluR4o (EC(50) = 0.009 microM). At the KA-preferring receptors GluR5 and GluR6/KA2, (S)-2-Me-Tet-AMPA showed much weaker agonist effects (EC(50) = 8.7 and 15.3 microM, respectively). It is concluded that (S)-2-Me-Tet-AMPA is a subunit-selective and highly potent AMPA receptor agonist and a potentially useful tool for studies of physiological AMPA receptor subtypes.
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Affiliation(s)
- S B Vogensen
- NeuroScience, PharmaBiotec Research Center, Department of Medicinal Chemistry, The Royal Danish School of Pharmacy, Copenhagen, Denmark
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14
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Stensbøl TB, Borre L, Johansen TN, Egebjerg J, Madsen U, Ebert B, Krogsgaard-Larsen P. Resolution, absolute stereochemistry and molecular pharmacology of the enantiomers of ATPA. Eur J Pharmacol 1999; 380:153-62. [PMID: 10513575 DOI: 10.1016/s0014-2999(99)00512-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
(RS)-2-Amino-3-(5-tert-butyl-3-hydroxy-4-isoxazolyl)propionic acid (ATPA), an analogue of (RS)-2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid (AMPA). has previously been shown to be a relatively weak AMPA receptor agonist and a very potent agonist at the GluR5 subtype of kainic acid-preferring (S)-glutamic acid ((S)-Glu) receptors. We report here the separation of (+)- and (-)-ATPA, obtained at high enantiomeric purity (enantiomeric excess values of 99.8% and > 99.8%, respectively) using chiral chromatography, and the unequivocal assignment of the stereochemistry of (S)-(+)-ATPA and (R)-(-)-ATPA. (S)- and (R)-ATPA were characterized in receptor binding studies using rat brain membranes, and electrophysiologically using the rat cortical wedge preparation and cloned AMPA-preferring (GluR1, GluR3, and GluR4) and kainic acid-preferring (GluR5, GluR6, and GluR6 + KA2) receptors expressed in Xenopus oocytes. In the cortical wedge, (S)-ATPA showed AMPA receptor agonist effects (EC50 = 23 microM) approximately twice as potent as those of ATPA. (R)-ATPA antagonized depolarizations induced by AMPA (Ki = 253 microM) and by (S)-ATPA (Ki = 376 microM), and (R)-ATPA antagonized the biphasic depolarizing effects induced by kainic acid (Ki = 301 microM and 1115 microM). At cloned AMPA receptors, (S)-ATPA showed agonist effects at GluR3 and GluR4 with EC50 values of approximately 8 microM and at GluR1 (EC50 = 22 microM), producing maximal steady state currents only 5.4-33% of those evoked by kainic acid. (R)-ATPA antagonized currents evoked by kainic acid at cloned AMPA receptor subtypes with Ki values of 33-75 microM. (S)-ATPA produced potent agonist effects at GluR5 (EC50 = 0.48 microM). Due to desensitization of GluR5 receptors, which could not be fully prevented by treatment with concanavalin A, (S)-ATPA-induced agonist effects were normalized to those of kainic acid. Under these circumstances, maximal currents produced by (S)-ATPA and kainic acid were not significantly different. (R)-ATPA did not attenuate currents produced by kainic acid at GluR5, and neither (S)- nor (R)-ATPA showed significant effects at GluR6. (S)-ATPA as well as AMPA showed weak agonist effects at heteromeric GluR6 + KA2 receptors, whereas (R)-ATPA was inactive. Thus, (S)- and (R)-ATPA may be useful tools for mechanistic studies of ionotropic non-NMDA (S)-Glu receptors, and lead structures for the design of new subtype-selective ligands for such receptors.
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Affiliation(s)
- T B Stensbøl
- PharmaBiotec NeuroScience Research Center, Department of Medicinal Chemistry, The Royal Danish School of Pharmacy, Copenhagen
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Falch E, Brehm L, Mikkelsen I, Johansen TN, Skjaerbaek N, Nielsen B, Stensbøl TB, Ebert B, Krogsgaard-Larsen P. Heteroaryl analogues of AMPA. 2. Synthesis, absolute stereochemistry, photochemistry, and structure-activity relationships. J Med Chem 1998; 41:2513-23. [PMID: 9651156 DOI: 10.1021/jm9801206] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
We have previously shown that (S)-2-amino-3-(3-hydroxy-5-phenyl-4-isoxazolyl)propionic acid [(S)-APPA, 2] is a weak agonist at (RS)-2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid (AMPA) receptors, specifically activated by (S)-AMPA (1), whereas (S)-2-amino-3-[3-hydroxy-5-(2-pyridyl)-4-isoxazolyl]propionic acid [(S)-2-Py-AMPA, 5] and (RS)-2-amino-3-[3-hydroxy-5-(2-thiazolyl)-4-isoxazolyl]propionic acid (4) are potent AMPA agonists. On the other hand, (R)-APPA (3) and (R)-2-Py-AMPA (6) have been shown to be weak AMPA antagonists. We now report the synthesis of 2-Py-AMPA (7a) and the isomeric compounds 3-Py-AMPA (7b) and 4-Py-AMPA (7c) as well as the 7a analogues, (RS)-2-amino-3-[3-hydroxy-5-(6-methyl-2-pyridyl)-4-isoxazolyl]p ropion ic acid (7d) and (RS)-2-amino-3-[3-hydroxy-5-(2-quinolinyl)-4-isoxazolyl]propionic acid (7e). Furthermore, (RS)-2-amino-3-[3-hydroxy-5-(2-furyl)-4-isoxazolyl]propionic acid (2-Fu-AMPA, 7f) and its 5-bromo-2-furyl derivative (7g) were synthesized, and (S)-2-Fu-AMPA (8) and (R)-2-Fu-AMPA (9) were prepared by semipreparative chiral HPLC resolution of 7f. HPLC analyses and circular dichroism spectroscopy indicated the absolute stereochemistry of 8 and 9 to be S and R, respectively. This was confirmed by an X-ray crystallographic analysis of 9.HCl. In receptor binding (IC50 values) and rat cortical wedge electrophysiological (EC50 values) studies, 7c (IC50 = 5.5 +/- 0.6 microM; EC50 = 96 +/- 5 microM) was shown to be markedly weaker than 7a (IC50 = 0.57 +/- 0.16 microM; EC50 = 7.4 +/- 0.2 microM) as an AMPA agonist, whereas 7b,d,e were inactive. The very potent AMPA agonist effect of 7f (IC50 = 0.15 +/- 0.03 microM; EC50 = 1.7 +/- 0. 2 microM) was shown to reside exclusively in 8 (IC50 = 0.11 +/- 0.01 microM; EC50 = 0.71 +/- 0.11 microM), whereas 9 did not interact significantly with AMPA receptors, either as an agonist or as an antagonist. 8 was shown to be photochemically active and is a potential photoaffinity label for the recognition site of the AMPA receptors. Compound 7g turned out to be a very weak AMPA receptor agonist (IC50 = 12 +/- 0.7 microM; EC50 = 160 +/- 15 microM). None of these new compounds showed detectable effects at N-methyl-d-aspartic acid (NMDA) or kainic acid receptors in vitro. The present studies have emphasized that the presence of a heteroatom in the 2-position of the heteroaryl 5-substituent greatly facilitates AMPA receptor agonist activity.
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Affiliation(s)
- E Falch
- PharmaBiotec Research Center, Department of Medicinal Chemistry, The Royal Danish School of Pharmacy, 2 Universitetsparken, DK-2100 Copenhagen, Denmark
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Johansen TN, Ebert B, Bräuner-Osborne H, Didriksen M, Christensen IT, Søby KK, Madsen U, Krogsgaard-Larsen P, Brehm L. Excitatory amino acid receptor ligands: resolution, absolute stereochemistry, and enantiopharmacology of 2-amino-3-(4-butyl-3-hydroxyisoxazol-5-yl)propionic acid. J Med Chem 1998; 41:930-9. [PMID: 9526567 DOI: 10.1021/jm9706731] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
(RS)-2-Amino-3-(4-butyl-3-hydroxyisoxazol-5-yl)propionic acid (Bu-HIBO, 6) has previously been shown to be an agonist at (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA) receptors and an inhibitor of CaCl2-dependent [3H]-(S)-glutamic acid binding (J. Med. Chem. 1992, 35, 3512-3519). To elucidate the pharmacological significance of this latter binding affinity, which is also shown by quisqualic acid (3) but not by AMPA, we have now resolved Bu-HIBO via diastereomeric salt formation using the diprotected Bu-HIBO derivative 11 and the enantiomers of 1-phenylethylamine (PEA). The absolute stereochemistry of (S)-Bu-HIBO (7) (ee = 99.0%) and (R)-Bu-HIBO (8) (ee > 99.6%) were established by an X-ray crystallographic analysis of compound 15, a salt of (R)-PEA, and diprotected 8. Circular dichroism spectra of 7 and 8 were recorded. Whereas 7 (IC50 = 0.64 microM) and 8 (IC50 = 0.57 microM) were equipotent as inhibitors of CaCl2-dependent [3H]-(S)-glutamic acid binding, neither enantiomer showed significant affinity for the synaptosomal (S)-glutamic acid uptake system(s). AMPA receptor affinity (IC50 = 0.48 microM) and agonism (EC50 = 17 microM) were shown to reside exclusively in the S-enantiomer, 7. Compounds 7 and 8 did not interact detectably with kainic acid or N-methyl-D-aspartic acid (NMDA) receptor sites. Neither 7 nor 8 affected the function of the metabotropic (S)-glutamic acid receptors mGlu2 and mGlu4a, expressed in CHO cells. Compound 8 was shown also to be inactive at mGlu1 alpha, whereas 7 was determined to be a moderately potent antagonist at mGlu1 alpha (Ki = 110 microM) and mGlu5a (Ki = 97 microM). Using the rat cortical wedge preparation, the AMPA receptor agonist effect of 7 was markedly potentiated by coadministration of 8 at 21 degrees C, but not at 2-4 degrees C. These observations together indicate that the potentiation of the AMPA receptor agonism of 7 by 8 is not mediated by metabotropic (S)-glutamate receptors but rather by the CaCl2-dependent (S)-glutamic acid binding system, which shows the characteristics of a transport mechanism. After intravenous administration in mice, 7 (ED50 = 44 mumol/kg) was slightly more potent than AMPA (1) (ED50 = 55 mumol/kg) and twice as potent as Bu-HIBO (6) (ED50 = 94 mumol/kg) as a convulsant, whereas 8 was inactive. After subcutaneous administration in mice, Bu-HIBO (ED50 = 110 mumol/kg) was twice as potent as AMPA (ED50 = 220 mumol/kg) as a convulsant. Since 7 and Bu-HIBO (EC50 = 37 microM) are much weaker than AMPA (EC50 = 3.5 microM) as AMPA receptor agonists in vitro, the presence of a butyl group in the molecules of Bu-HIBO and 7 seems to facilitate the penetration of these compounds through the blood-brain barrier.
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Affiliation(s)
- T N Johansen
- PharmaBiotec Research Center, Department of Medicinal Chemistry, Royal Danish School of Pharmacy, 2 Universitetsparken, Copenhagen, Denmark
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Indirect separation of chiral proteinogenic α-amino acids using the fluorescence active (1R,2R)-N-[(2-isothiocyanato)cyclohexyl]-6-methoxy-4-quinolinylamide) as chiral derivatizing agent. J Chromatogr A 1998. [DOI: 10.1016/s0021-9673(97)00869-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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18
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Skjaerbaek N, Brehm L, Johansen TN, Hansen LM, Nielsen B, Ebert B, Søby KK, Stensbøl TB, Falch E, Krogsgaard-Larsen P. Aryl and cycloalkyl analogues of AMPA: synthetic, pharmacological and stereochemical aspects. Bioorg Med Chem 1998; 6:119-31. [PMID: 9502111 DOI: 10.1016/s0968-0896(97)10017-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
We have previously shown that (RS)-2-amino-3-(3-hydroxy-5-phenylisoxazol-4-yl)propionic acid (APPA, 2) is a functional partial agonist at the (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA) subtype of excitatory amino acid receptors, reflecting that (S)-APPA is a full agonist and (R)-APPA a competitive antagonist at AMPA receptors. We have now synthesized and pharmacologically characterized (RS)-2-amino-3-[3-hydroxy-5-(2-fluorophenyl)isoxazol-4-yl]propioni c acid (2-F-APPA, 5a), 3-F-APPA (5b), 4-F-APPA (5c), (S)-4-F-APPA (6), (R)-4-F-APPA (7), and the fully and partially, respectively, saturated APPA (2) analogues, (RS)-2-amino-3-(3-hydroxy-5-cyclohexylisoxazol-4-yl)propionic acid (5d) and compound 5e containing a 1-cyclohexenyl ring. The absolute stereochemistry of 6 and 7 was established on the basis of comparative circular dichroism studies on 6, 7, and (S)- and (R)-APPA. 4-F-APPA (5c), (S)-4-F-APPA (6), 5d, and 5e were shown to selectively inhibit [3H]AMPA binding and to activate AMPA receptors. Whereas (S)-4-F-APPA (6) showed full AMPA receptor agonism, (R)-4-F-APPA (7) was an AMPA receptor antagonist. Co-administration of (S)- and (R)-4-F-APPA to the rat cortical wedge preparation produced functional partial AMPA receptor agonism. Semi empirical calculations showed that the magnitude of the torsional angle of the bond connecting the two rings in the series of nonannulated bicyclic AMPA analogues appears to be of importance for the potency and efficacy of these compounds.
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Affiliation(s)
- N Skjaerbaek
- PharmaBiotec Research Centre, Department of Medicinal Chemistry, The Royal Danish School of Pharmacy, Copenhagen, Denmark
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Johansen TN, Frydenvang K, Ebert B, Madsen U, Krogsgaard-Larsen P. Excitatory amino acid receptor antagonists: resolution, absolute stereochemistry, and pharmacology of (S)- and (R)-2-amino-2-(5-tert-butyl-3-hydroxyisoxazol-4-yl)acetic acid (ATAA). Chirality 1997; 9:529-36. [PMID: 9329180 DOI: 10.1002/(sici)1520-636x(1997)9:5/6<529::aid-chir20>3.0.co;2-p] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We have previously shown that (RS)-2-amino-2-(5-tert-butyl-3-hydroxyisoxazol-4-yl)acetic acid (ATAA) is an antagonist at N-methyl-D-aspartic acid (NMDA) and (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA) receptors. We have now resolved ATAA via diastereomeric salt formation using N-BOC protected ATAA and (R)- and (S)-phenylethylamine. Enantiomeric purities (ee > 98%) of (R)- and (S)-ATAA were determined using the Crownpak CR(-) and CR(+) columns, respectively. The absolute configuration of (R)-ATAA was established by an X-ray crystallographic analysis of the (R)-phenylethylamine salt of N-BOC-(R)-ATAA. Like ATAA, neither (R)- nor (S)-ATAA significantly affected (IC50 > 100 microM) the receptor binding of tritiated AMPA, kainic acid, or (RS)-3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid, the latter being a competitive NMDA antagonist. Electrophysiological experiments, using the rat cortical wedge preparation, showed the NMDA antagonist effect as well as the AMPA antagonist effect of ATAA to reside exclusively in the (R)-enantiomer (Ki = 75 +/- 5 microM and 57 +/- 1 microM, respectively). Neither (R)- nor (S)-ATAA significantly reduced kainic acid-induced excitation (Ki > 1,000 microM).
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Affiliation(s)
- T N Johansen
- Department of Medicinal Chemistry, Royal Danish School of Pharmacy, Copenhagen, Denmark
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20
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Ahmadian H, Nielsen B, Bräuner-Osborne H, Johansen TN, Stensbøl TB, Sløk FA, Sekiyama N, Nakanishi S, Krogsgaard-Larsen P, Madsen U. (S)-homo-AMPA, a specific agonist at the mGlu6 subtype of metabotropic glutamic acid receptors. J Med Chem 1997; 40:3700-5. [PMID: 9357538 DOI: 10.1021/jm9703597] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Our previous publication (J. Med. Chem. 1996, 39, 3188-3194) described (RS)-2-amino-4-(3-hydroxy-5-methylisoxazol-4-yl)butyric acid (Homo-AMPA) as a highly selective agonist at the mGlu6 subtype of metabotropic excitatory amino acid (EAA) receptors. Homo-AMPA has already become a standard agonist for the pharmacological characterization of mGlu6 (Trends Pharmacol. Sci. Suppl. 1997, 37-39), and we here report the resolution, configurational assignment, and pharmacology of (S)- (6) and (R)- (7) Homo-AMPA. Using the "Ugi four-component condensation", 3-(3-ethoxy-5-methylisoxazol-4-yl)propanal (10) was converted into the separable diastereomeric derivatives of 6 and 7, compounds 12 and 11, respectively. Deprotection of 12, in one or two steps, gave extensively racemized 6, which was converted in low yield into 6 (99.0% ee) through several crystallizations. 6 (99.7% ee) and 7 (99.9% ee) were finally obtained by preparative chiral HPLC. The configurational assignments of 6 and 7 were based on 1H NMR spectroscopic studies on 12 and 11, respectively, and circular dichroism studies on 6 and 7. Values of optical rotations using different solvents and the chiral HPLC elution order of 6 and 7 supported the results of the spectroscopic configurational assignments. The activities of 6 and 7 at ionotropic EAA (iGlu) receptors and at mGlu1-7 were studied. (S)-Homo-AMPA (6) was shown to be a specific agonist at mGlu6 (EC50 = 58 +/- 11 microM) comparable in potency with the endogenous mGlu agonist (S)-glutamic acid (EC50 = 20 +/- 3 microM). Although Homo-AMPA did not show significant effects at iGlu receptors, (R)-Homo-AMPA (7), which was inactive at mGlu1-7, turned out to be a weak N-methyl-D-aspartic acid (NMDA) receptor antagonist (IC50 = 131 +/- 18 microM).
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Affiliation(s)
- H Ahmadian
- Department of Medicinal Chemistry, Royal Danish School of Pharmacy, Copenhagen, Denmark
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21
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Johansen TN, Ebert B, Falch E, Krogsgaard-Larsen P. AMPA receptor agonists: resolution, configurational assignment, and pharmacology of (+)-(S)- and (-)-(R)-2-amino-3-[3-hydroxy-5-(2-pyridyl)-isoxazol-4-yl]-propionic acid (2-Py-AMPA). Chirality 1997; 9:274-80. [PMID: 9176992 DOI: 10.1002/(sici)1520-636x(1997)9:3<274::aid-chir12>3.0.co;2-k] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We have previously shown that whereas (RS)-2-amino-3-(3-hydroxy-5-phenylisoxazol-4-yl)propionic acid (APPA) shows the characteristics of a partial agonist at (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA) receptors, (S)-APPA is a full AMPA receptor agonist and (R)-APPA a weak competitive AMPA receptor antagonist. This observation led us to introduce the new pharmacological concept, functional partial agonism. Recently we have shown that the 2-pyridyl analogue of APPA, (RS)-2-amino-3-[3-hydroxy-5-(2-pyridyl)isoxazol-4-yl]propionic acid (2-Py-AMPA), is a potent and apparently full AMPA receptor agonist, and this compound has now been resolved into (+)- and (-)-2-Py-AMPA (ee > or = 99.0%) by chiral HPLC using a Chirobiotic T column. The absolute stereochemistry of the enantiomers of APPA has previously been established by X-ray analysis, and on the basis of comparative studies of the circular dichroism spectra of the enantiomers of APPA and 2-Py-AMPA, (+)- and (-)-2-Py-AMPA were assigned the (S)- and (R)-configuration, respectively. In a series of receptor binding studies, neither enantiomer of 2-Py-AMPA showed detectable affinity for kainic acid receptor sites or different sites at the N-methyl-D-aspartic acid (NMDA) receptor complex. (+)-(S)-2-Py-AMPA was an effective inhibitor of [3H]AMPA binding (IC50 = 0.19 +/- 0.06 microM) and a potent AMPA receptor agonist in the rat cortical wedge preparation (EC50 = 4.5 +/- 0.3 microM) comparable with AMPA (IC50 = 0.040 +/- 0.01 microM; EC50 = 3.5 +/- 0.2 microM), but much more potent than (+)-(S)-APPA (IC50 = 5.5 +/- 2.2 microM; EC50 = 230 +/- 12 microM). Like (-)-(R)-APPA (IC50 > 100 microM), (-)-(R)-2-Py-AMPA (IC50 > 100 microM) did not significantly affect [3H]AMPA binding, and both compounds were weak AMPA receptor antagonists (Ki = 270 +/- 50 and 290 +/- 20 microM, respectively).
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Affiliation(s)
- T N Johansen
- Department of Medicinal Chemistry, Royal Danish School of Pharmacy, Copenhagen, Denmark
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22
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Madsen U, Frydenvang K, Ebert B, Johansen TN, Brehm L, Krogsgaard-Larsen P. N-methyl-D-aspartic acid receptor agonists: resolution, absolute stereochemistry, and pharmacology of the enantiomers of 2-amino-2-(3-hydroxy-5-methyl-4-isoxazolyl)acetic acid. J Med Chem 1996; 39:183-90. [PMID: 8568805 DOI: 10.1021/jm950393q] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
(R,S)-2-Amino-2-(3-hydroxy-5-methyl-4-isoxazolyl)acetic acid [(R,S)-AMAA, 4] is a potent and selective agonist at the N-methyl-D-aspartic acid (NMDA) subtype of excitatory amino acid receptors. Using the Ugi "four-component condensation" method, the two diastereomers (2R)- and (2S)-2-[3-(benzyloxy)-5-methyl-4-isoxazolyl]N-tert-butyl-2- [N-[(S)-1-phenylethyl]benzamido]-acetamide (16 and 17, respectively) were synthesized and separated chromatographically. The absolute stereochemistry of 16 was confirmed by an X-ray analysis. Deprotection of these intermediates did, however, provide (R)- (8) and (S)- (9) AMAA, respectively, in extensively racemized forms. N-BOC-protected (R,S)-AMAA (21) was successfully resolved via diastereomeric salt formation using cinchonidine. The stereochemical purity and stability of 8 and 9 obtained via this resolution were determined using chiral HPLC. (R)-AMAA (8) showed peak affinity for [3H]AMPA receptor sites (IC50 = 72 +/- 13 microM) and was shown to be a more potent inhibitor of [3H]CPP binding (IC50 = 3.7 +/- 1.5 microM) than (S)-AMAA (9) (IC50 = 61 +/- 6.4 microM). Neither enantiomer of AMAA affected [3H]kainic acid receptor binding significantly. In electrophysiological studies using rat brain tissue, 8 (EC50 = 7.3 +/- 0.3 microM) was 1 order of magnitude more potent than 9 (EC50 = 75 +/- 9 microM) as an NMDA receptor agonist.
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Affiliation(s)
- U Madsen
- Department of Medicinal Chemistry, Royal Danish School of Pharmacy, Copenhagen, Denmark
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23
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Scaloni A, Simmaco M, Bossa F. D-L amino acid analysis using automated precolumn derivatization with 1-fluoro-2,4-dinitrophenyl-5-alanine amide. Amino Acids 1995; 8:305-13. [DOI: 10.1007/bf00806826] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/1994] [Accepted: 08/01/1994] [Indexed: 10/26/2022]
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24
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Chang SC, Wang LR, Armstrong DW. Facile Resolution OF N-tert-Butoxy-Carbonyl Amino Acids: The Importance of Enantiomeric Purity in Peptide Synthesis. ACTA ACUST UNITED AC 1992. [DOI: 10.1080/10826079208018297] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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25
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Mathur R, Bohra S, Mathur V, Narang CK, Mathur NK. Chiral ligand exchange chromatography on polygalactomannan (Guaran). Chromatographia 1992. [DOI: 10.1007/bf02275913] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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26
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Enantiomeric separation of 5-Fluoro- and 6-Fluoro-d/l-dopa (3,4-dihydroxyphenylalanine). ACTA ACUST UNITED AC 1992. [DOI: 10.1007/bf00322383] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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27
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Separation and estimation of small amounts of the enantiomers of carbidopa and methyldopa on a chiral stationary phase with l-phenylalanine as selector in ligand-exchange chromatography. J Chromatogr A 1991. [DOI: 10.1016/s0021-9673(01)88700-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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28
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29
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Trihalogenated benzamides: structure taste relationships. Eur Food Res Technol 1990. [DOI: 10.1007/bf01184500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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30
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Koziol TR, Grayeski ML. Investigations of the reversed-phase high-performance liquid chromatographic ligand-exchange retention mechanism on a triamine stationary phase. J Chromatogr A 1990. [DOI: 10.1016/s0021-9673(01)89432-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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31
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Abstract
HPLC analysis of food on various silica bonded phases has been described. Technical and theoretical aspects of the materials such as normal-, reverse-, ion-exchange-, affinity-, chiral-, size-exclusion-, and ion-phases have been discussed. Special problems such as mobile phase or solvent-selection, selectivity and mechanisms of resolution on these bonded phases have been mentioned. Application of various bonded materials such as amino, cyano, diol, amino-cyano, C-18, C-8, anion-exchangers, strong and weak-cation exchangers, chiral and enzyme bound affinity phases to analyze and determine food components such as carbohydrates, food colors and pigments, flavors, proteins, vitamins and toxins has been described.
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33
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Pinkerton TC, Koeplinger KA. High-performance liquid chromatographic separation of peptides on a diol-Gly-Phe-Phe tripeptide-bonded phase. J Chromatogr A 1988; 458:129-45. [PMID: 3235630 DOI: 10.1016/s0021-9673(00)90559-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The retention characteristics of some selected peptides (mol. wt. less than 2000 a.m.u.) have been investigated on a diol-Gly-Phe-Phe partitioning phase, bound to 5-microns porous silica. The hydrophobic, positively charged peptides can be separated with mild mobile phases, containing only acetonitrile and phosphate buffer. The peptide selectivity of the diol-Gly-Phe-Phe-bonded phase is uniquely different from that of a C8 column. The dependence of capacity factors on mobile phase pH, ionic strength, and organic solvent concentration demonstrated that the partitioning mechanisms of the diol-Gly-Phe-Phe phase involve multifunctional reversed-phase and cation-exchange processes.
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Affiliation(s)
- T C Pinkerton
- Control Division, Upjohn Company, Kalamazoo, MI 49001
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34
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Feitsma KG, Drenth BF. Chromatographic separation of enantiomers. PHARMACEUTISCH WEEKBLAD. SCIENTIFIC EDITION 1988; 10:1-11. [PMID: 3281134 DOI: 10.1007/bf01966428] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
In this paper a review is presented on the chromatographic analysis of enantiomers with special attention to high pressure liquid chromatography. Also, some examples of resolution of racemates by thin layer chromatography and gas chromatography are given. The various procedures in the surveyed literature have been divided into three main classes: procedures with formation of diastereomeric compounds prior to the chromatographic separation, procedures in which a chiral mobile phase is used, and procedures with the use of a chiral stationary phase. These methods are subdivided and some examples of their application to drugs and related compounds are presented.
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Affiliation(s)
- K G Feitsma
- Department of Analytical, Chemistry and Toxicology, State University of Groningen, the Netherlands
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35
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Chapter 3 Immobilization of Compounds for Selective Interaction with Analytes in Liquid Chromatography. ACTA ACUST UNITED AC 1988. [DOI: 10.1016/s0301-4770(08)60379-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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36
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Saigo K, Yuki Y, Kimoto H, Nishida T, Hasegawa M. A Novel Chiral Stationary Phase for Optical Resolution of Amino Acids and Their Derivatives by Ligand-Exchange High-Performance Liquid Chromatography. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 1988. [DOI: 10.1246/bcsj.61.322] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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37
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38
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Takeuchi T, Asai H, Ishii D. Enantiomeric separation of amino acids by micro high-performance liquid chromatography on an L-proline-bonded stationary phase. J Chromatogr A 1987; 407:151-8. [PMID: 3429504 DOI: 10.1016/s0021-9673(01)92612-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Enantiomeric separation of amino acids on an L-proline-bonded phase was examined in micro high-performance liquid chromatography. Gradient separation of seven pairs of racemic dansyl amino acids was achieved by connecting chiral and hydrophobic columns in series.
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Affiliation(s)
- T Takeuchi
- Department of Applied Chemistry, Faculty of Engineering, Nagoya University, Japan
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39
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Gübitz G, Juffmann F. Resolution of the enantiomers of thyroid hormones by high-performance ligand-exchange chromatography using a chemically bonded chiral stationary phase. J Chromatogr A 1987; 404:391-3. [PMID: 3667768 DOI: 10.1016/s0021-9673(01)86882-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- G Gübitz
- Institut für Pharmazeutische Chemie der Karl-Franzens-Universität, Graz, Austria
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40
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Yuki Y, Saigo K, Kimoto H, Tachibana K, Hasegawa M. Novel chiral stationary phases for optical resolution by ligand-exchange high-performance liquid chromatography. J Chromatogr A 1987; 400:65-75. [PMID: 3667760 DOI: 10.1016/s0021-9673(01)81599-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Novel chiral stationary phases, (1R,2S)- and diastereomeric (1S,2S)-2-carboxymethylamino-1,2-diphenylethanol, were prepared from (1R,2S)- and (1S,2S)-2-amino-1,2-diphenylethanol, respectively, and were bound to silica gel pretreated with 3-glycidoxypropyltrimethoxysilane. The chiral stationary phases were found to be very effective for the optical resolution of amino acids, amino acid derivatives and hydroxy acids by ligand-exchange high-performance liquid chromatography.
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Affiliation(s)
- Y Yuki
- Research Centre, Daicel Chemical Industries Ltd., Hyogo, Japan
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41
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Synthesis of DL-[3-11C]valine using [2-11C]isopropyl iodide, and preparation of L-[3-11C]valine by treatment with D-amino acid oxidase. ACTA ACUST UNITED AC 1987. [DOI: 10.1016/0883-2889(87)90134-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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42
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Chapter 7 The Direct Preparative Resolution Of Enantiomers By Liquid Chromatography On Chiral Stationary Phases. ACTA ACUST UNITED AC 1987. [DOI: 10.1016/s0301-4770(08)60370-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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43
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Yuki Y, Saigo K, Tachibana K, Hasegawa M. Novel Chiral Stationary Phases for the Resolution of the Enantiomers of Amino Acids by Ligand Exchange Chromatography. CHEM LETT 1986. [DOI: 10.1246/cl.1986.1347] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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44
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Gübitz G. Direct Separation of Enantiomers by High Performance Ligand Exchange Chromatography on Chemically Bonded Chiral Phases. ACTA ACUST UNITED AC 1986. [DOI: 10.1080/01483918608076651] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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45
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Däppen R, Arm H, Meyer VR. Applications and limitations of commercially available chiral stationary phases for high-performance liquid chromatography. J Chromatogr A 1986. [DOI: 10.1016/s0021-9673(00)80205-8] [Citation(s) in RCA: 119] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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46
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Bolster JM, ten Hoeve W, Vaalburg W, van Dijk TH, Zijlstra JB, Paans AM, Wynberg H, Woldring MG. The preparation of carbon-11 labelled proline for positron emission tomography. Preliminary distribution studies in rats with Walker 256 carcinosarcoma. THE INTERNATIONAL JOURNAL OF APPLIED RADIATION AND ISOTOPES 1985; 36:339-43. [PMID: 3874834 DOI: 10.1016/0020-708x(85)90272-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
DL-[1-11C]Proline has been synthesized by carboxylation of alpha-lithiopyrrolidyl-N-tert-butyl-formamidine with a radiochemical yield of up to 18% without correction for decay. The total synthesis time is 45 min. Accumulation of DL-[1-11C]proline has been shown in Walker 256 carcinosarcoma transplanted in rats. A tumor/non-tumor ratio of 5.9 was found at 45 min after i.v. injection.
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47
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Bolster JM, Vaalburg W, van Dijk TH, Zijlstra JB, Paans AM, Wynberg H, Woldring MG. Syntheses of carbon-11 labelled ornithine and lysine. Preliminary accumulation studies in rats with Walker 256 carcinosarcoma. THE INTERNATIONAL JOURNAL OF APPLIED RADIATION AND ISOTOPES 1985; 36:263-7. [PMID: 3926656 DOI: 10.1016/0020-708x(85)90082-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
DL-[1-11C]ornithine and lysine have been synthesized by carboxylation of the corresponding alpha-lithioisocyanide with a radiochemical yield of up to 14% without correction for decay. The total preparation time is 50 min. Accumulation of both DL-[1-11C]ornithine and lysine in Walker 256 carcinosarcoma is observed, with a tumor/non-tumor ratio of 4.9 and 4.5 respectively, at 45 min after intravenous injection.
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48
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Takayanagi H, Hashizume M, Fujimura K, Ando T. Ligand-exchange gas chromatography of dialkyl sulphides. J Chromatogr A 1985. [DOI: 10.1016/s0021-9673(01)93507-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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49
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In-situ Preparation of a chemically bonded chiral stationary phase for the separation of aromatic α-amino acid enantiomers. J Chromatogr A 1985. [DOI: 10.1016/s0021-9673(00)96012-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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50
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Takayanagi H, Akita M, Fujimura K, Ando T. Ligand-exchange gas chromatographic separation of aromatic sulphides. J Chromatogr A 1985. [DOI: 10.1016/s0021-9673(01)93508-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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