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Petrillo T, Semprini E, Tomatis V, Arnesano M, Ambrosetti F, Battipaglia C, Sponzilli A, Ricciardiello F, Genazzani AR, Genazzani AD. Putative Complementary Compounds to Counteract Insulin-Resistance in PCOS Patients. Biomedicines 2022; 10:biomedicines10081924. [PMID: 36009471 PMCID: PMC9406066 DOI: 10.3390/biomedicines10081924] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 07/25/2022] [Accepted: 08/04/2022] [Indexed: 11/16/2022] Open
Abstract
Polycystic ovary syndrome (PCOS) is the most frequent endocrine-metabolic disorder among women at reproductive age. The diagnosis is based on the presence of at least two out of three criteria of the Rotterdam criteria (2003). In the last decades, the dysmetabolic aspect of insulin resistance and compensatory hyperinsulinemia have been taken into account as the additional key features in the etiopathology of PCOS, and they have been widely studied. Since PCOS is a complex and multifactorial syndrome with different clinical manifestations, it is difficult to find the gold standard treatment. Therefore, a great variety of integrative treatments have been reported to counteract insulin resistance. PCOS patients need a tailored therapeutic strategy, according to the patient’s BMI, the presence or absence of familiar predisposition to diabetes, and the patient’s desire to achieve pregnancy or not. The present review analyzes and discloses the main clinical insight of such complementary substances.
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Affiliation(s)
- Tabatha Petrillo
- Gynecological Endocrinology Center, Department of Obstetrics and Gynecology, University of Modena and Reggio Emilia, 41121 Modena, Italy
| | - Elisa Semprini
- Gynecological Endocrinology Center, Department of Obstetrics and Gynecology, University of Modena and Reggio Emilia, 41121 Modena, Italy
| | - Veronica Tomatis
- Gynecological Endocrinology Center, Department of Obstetrics and Gynecology, University of Modena and Reggio Emilia, 41121 Modena, Italy
| | - Melania Arnesano
- Gynecological Endocrinology Center, Department of Obstetrics and Gynecology, University of Modena and Reggio Emilia, 41121 Modena, Italy
| | - Fedora Ambrosetti
- Gynecological Endocrinology Center, Department of Obstetrics and Gynecology, University of Modena and Reggio Emilia, 41121 Modena, Italy
| | - Christian Battipaglia
- Gynecological Endocrinology Center, Department of Obstetrics and Gynecology, University of Modena and Reggio Emilia, 41121 Modena, Italy
| | - Alessandra Sponzilli
- Gynecological Endocrinology Center, Department of Obstetrics and Gynecology, University of Modena and Reggio Emilia, 41121 Modena, Italy
| | - Francesco Ricciardiello
- Gynecological Endocrinology Center, Department of Obstetrics and Gynecology, University of Modena and Reggio Emilia, 41121 Modena, Italy
| | - Andrea R. Genazzani
- Department of Obstetrics and Gynecology, University of Pisa, 56126 Pisa, Italy
| | - Alessandro D. Genazzani
- Gynecological Endocrinology Center, Department of Obstetrics and Gynecology, University of Modena and Reggio Emilia, 41121 Modena, Italy
- Correspondence:
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Petrillo T, Battipaglia C, Virmani MA, Genazzani AR, Genazzani AD. Neuroendocrine Effects of Carnitines on Reproductive Impairments. Int J Mol Sci 2021; 22:ijms221910781. [PMID: 34639120 PMCID: PMC8509461 DOI: 10.3390/ijms221910781] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 09/28/2021] [Accepted: 10/03/2021] [Indexed: 12/14/2022] Open
Abstract
Carnitines are quaternary amines involved in various cellular processes such as fatty acid uptake, β-oxidation and glucose metabolism regulation. Due to their neurotrophic activities, their integrative use has been studied in several different physio-pathological conditions such as anorexia nervosa, chronic fatigue, vascular diseases, Alzheimer’s disease and male infertility. Being metabolically active, carnitines have also been proposed to treat reproductive impairment such as functional hypothalamic amenorrhea (FHA) and polycystic ovary syndrome (PCOS) since they improve both hormonal and metabolic parameters modulating the neuroendocrine impairments of FHA. Moreover, they are capable of improving the lipid profile and the insulin sensitivity in patients with PCOS.
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Affiliation(s)
- Tabatha Petrillo
- Gynecological Endocrinology Center, Department of Obstetrics and Gynecology, University of Modena and Reggio Emilia, 41121 Modena, Italy; (T.P.); (C.B.)
| | - Christian Battipaglia
- Gynecological Endocrinology Center, Department of Obstetrics and Gynecology, University of Modena and Reggio Emilia, 41121 Modena, Italy; (T.P.); (C.B.)
| | | | - Andrea R. Genazzani
- Department of Obstetrics and Gynecology, University of Pisa, 56126 Pisa, Italy;
| | - Alessandro D. Genazzani
- Gynecological Endocrinology Center, Department of Obstetrics and Gynecology, University of Modena and Reggio Emilia, 41121 Modena, Italy; (T.P.); (C.B.)
- Correspondence:
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Prior A, van de Nieuwenhuijzen E, de Jong GJ, Somsen GW. Enantioselective micellar electrokinetic chromatography of dl-amino acids using (+)-1-(9-fluorenyl)-ethyl chloroformate derivatization and UV-induced fluorescence detection. J Sep Sci 2018; 41:2983-2992. [PMID: 29785784 PMCID: PMC6099287 DOI: 10.1002/jssc.201800204] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Revised: 05/11/2018] [Accepted: 05/16/2018] [Indexed: 01/24/2023]
Abstract
Chiral analysis of dl-amino acids was achieved by micellar electrokinetic chromatography coupled with UV-excited fluorescence detection. The fluorescent reagent (+)-1-(9-fluorenyl)ethyl chloroformate was employed as chiral amino acid derivatizing agent and sodium dodecyl sulfate served as pseudo-stationary phase for separating the formed amino acid diastereomers. Sensitive analysis of (+)-1-(9-fluorenyl)ethyl chloroformate-amino acids was achieved applying a xenon-mercury lamp for ultraviolet excitation, and a spectrograph and charge-coupled device for wavelength-resolved emission detection. Applying signal integration over a 30 nm emission wavelength interval, signal-to-noise ratios for derivatized amino acids were up to 23 times higher as obtained using a standard photomultiplier for detection. The background electrolyte composition (electrolyte, pH, sodium dodecyl sulfate concentration, and organic solvent) was studied in order to attain optimal chemo- and enantioseparation. Enantioseparation of 12 proteinogenic dl-amino acids was achieved with chiral resolutions between 1.2 and 7.9, and detection limits for most derivatized amino acids in the 13-60 nM range (injected concentration). Linearity (coefficients of determination > 0.985) and peak-area and migration-time repeatabilities (relative standard deviations lower than 2.6 and 1.9%, respectively) were satisfactory. The employed fluorescence detection system provided up to 100-times better signal-to-noise ratios for (+)-1-(9-fluorenyl)ethyl chloroformate-amino acids than ultraviolet absorbance detection, showing good potential for d-amino acid analysis.
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Affiliation(s)
- Amir Prior
- Division of BioAnalytical Chemistry, Amsterdam Institute for Molecules, Medicines and SystemsVrije Universiteit AmsterdamAmsterdamThe Netherlands
| | - Erik van de Nieuwenhuijzen
- Division of BioAnalytical Chemistry, Amsterdam Institute for Molecules, Medicines and SystemsVrije Universiteit AmsterdamAmsterdamThe Netherlands
| | | | - Govert W. Somsen
- Division of BioAnalytical Chemistry, Amsterdam Institute for Molecules, Medicines and SystemsVrije Universiteit AmsterdamAmsterdamThe Netherlands
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Moldovan RC, Bodoki E, Servais AC, Crommen J, Oprean R, Fillet M. (+) or (-)-1-(9-fluorenyl)ethyl chloroformate as chiral derivatizing agent: A review. J Chromatogr A 2017; 1513:1-17. [PMID: 28756893 DOI: 10.1016/j.chroma.2017.07.045] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Revised: 07/10/2017] [Accepted: 07/12/2017] [Indexed: 11/25/2022]
Abstract
Over the last 30years, (±)-1-(9-fluorenyl)ethyl chloroformate ((±)-FLEC) was used as a chiral derivatizing agent in various analytical applications involving a wide range of endogenous, pharmaceutical and environmentally relevant molecules. This comprehensive review aims to present all the significant aspects related to the state of the art in FLEC labeling and subsequent chiral separation of the resulting diastereomers using LC, SFC and CE techniques.
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Affiliation(s)
- Radu-Cristian Moldovan
- Laboratory for the Analysis of Medicines, Department of Pharmacy, Faculty of Medicine, CIRM, University of Liege,Avenue Hippocrate 15, B36-+3-T4, 4000 Liege, Belgium; Department of Analytical Chemistry and Instrumental Analysis, Faculty of Pharmacy, "Iuliu Hațieganu" University of Medicine and Pharmacy Cluj-Napoca,4 Louis Pasteur street, 400349 Cluj-Napoca, Romania
| | - Ede Bodoki
- Department of Analytical Chemistry and Instrumental Analysis, Faculty of Pharmacy, "Iuliu Hațieganu" University of Medicine and Pharmacy Cluj-Napoca,4 Louis Pasteur street, 400349 Cluj-Napoca, Romania
| | - Anne-Catherine Servais
- Laboratory for the Analysis of Medicines, Department of Pharmacy, Faculty of Medicine, CIRM, University of Liege,Avenue Hippocrate 15, B36-+3-T4, 4000 Liege, Belgium
| | - Jacques Crommen
- Laboratory for the Analysis of Medicines, Department of Pharmacy, Faculty of Medicine, CIRM, University of Liege,Avenue Hippocrate 15, B36-+3-T4, 4000 Liege, Belgium
| | - Radu Oprean
- Department of Analytical Chemistry and Instrumental Analysis, Faculty of Pharmacy, "Iuliu Hațieganu" University of Medicine and Pharmacy Cluj-Napoca,4 Louis Pasteur street, 400349 Cluj-Napoca, Romania
| | - Marianne Fillet
- Laboratory for the Analysis of Medicines, Department of Pharmacy, Faculty of Medicine, CIRM, University of Liege,Avenue Hippocrate 15, B36-+3-T4, 4000 Liege, Belgium.
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Isaguirre AC, Acosta G, Cerutti S, Fernandez LP. New flow injection method for quality control of dietary supplements containing l-carnitine using extraction mediated by sodium taurodeoxycholate coacervate coupled to molecular fluorescence. Microchem J 2016. [DOI: 10.1016/j.microc.2016.06.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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6
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Enantioselective capillary electrophoresis-mass spectrometry of amino acids in cerebrospinal fluid using a chiral derivatizing agent and volatile surfactant. Anal Chim Acta 2016; 940:150-8. [PMID: 27662770 DOI: 10.1016/j.aca.2016.08.040] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 08/23/2016] [Accepted: 08/24/2016] [Indexed: 12/12/2022]
Abstract
The sensitivity of coupled enantioselective capillary electrophoresis-mass spectrometry (CE-MS) of amino acids (AAs) is often hampered by the chiral selectors in the background electrolyte (BGE). A new method is presented in which the use of a chiral selector is circumvented by employing (+)-1-(9-fluorenyl)ethyl chloroformate (FLEC) as chiral AA derivatizing agent and ammonium perfluorooctanoate (APFO) as a volatile pseudostationary phase for separation of the formed diastereomers. Efficient AA derivatization with FLEC was completed within 10 min. Infusion experiments showed that the APFO concentration hardly affects the MS response of FLEC-AAs and presents significantly less ion suppression than equal concentrations of ammonium acetate. The effect of the pH and APFO concentration of the BGE and the capillary temperature were studied in order to achieve optimized enantioseparation. Optimization of CE-MS parameters, such as sheath-liquid composition and flow rate, ESI and MS settings was performed in order to prevent analyte fragmentation and achieve sensitive detection. Selective detection and quantification of 14 chiral proteinogenic AAs was achieved with chiral resolution between 1.2 and 8.6, and limits of detection ranging from 130 to 630 nM injected concentration. Aspartic acid and glutamic acid were detected, but not enantioseparated. The optimized method was applied to the analysis of chiral AAs in cerebrospinal fluid (CSF). Good linearity (R(2) > 0.99) and acceptable peak area and electrophoretic mobility repeatability (RSDs below 21% and 2.4%, respectively) were achieved for the chiral proteinogenic AAs, with sensitivity and chiral resolution mostly similar to obtained for standard solutions. Next to l-AAs, endogenous levels of d-serine and d-glutamine could be measured in CSF revealing enantiomeric ratios of 4.8%-8.0% and 0.34%-0.74%, respectively, and indicating the method's potential for the analysis of low concentrations of d-AAs in presence of abundant l-AAs.
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Ilisz I, Aranyi A, Péter A. Chiral derivatizations applied for the separation of unusual amino acid enantiomers by liquid chromatography and related techniques. J Chromatogr A 2013; 1296:119-39. [PMID: 23598164 DOI: 10.1016/j.chroma.2013.03.034] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Revised: 03/14/2013] [Accepted: 03/14/2013] [Indexed: 12/25/2022]
Abstract
Amino acids are essential for life, and have many functions in metabolism. One particularly important function is to serve as the building blocks of peptides and proteins, giving rise complex three dimensional structures through disulfide bonds or crosslinked amino acids. Peptides are frequently cyclic and contain proteinogenic as well as nonproteinogenic amino acids in many instances. Since most of the proteinogenic α-amino acids contain at least one stereogenic center (with the exception of glycine), the stereoisomers of all these amino acids and the peptides in which they are to be found may possess differences in biological activity in living systems. The impetus for advances in chiral separation has been highest in the past 25 years and this still continues to be an area of high focus. The important analytical task of the separation of isomers is achieved mainly by chromatographic and electrophoretic methods. This paper reviews indirect separation approaches, i.e. derivatization reactions aimed at creating the basis for the chromatographic resolution of biologically and pharmaceutically important enantiomers of unusual amino acids and related compounds, with emphasis on the literature published from 1980s. The main aspects of the chiral derivatization of amino acids are discussed, i.e. derivatization on the amino group, transforming the molecules into covalently bonded diastereomeric derivatives through the use of homochiral derivatizing agents. The diastereomers formed (amides, urethanes, urea and thiourea derivatives, etc.) can be separated on achiral stationary phases. The applications are considered, and in some cases different derivatizing agents for the resolution of complex mixtures of proteinogenic d,l-amino acids, non-proteinogenic amino acids and peptides/amino acids from peptide syntheses or microorganisms are compared.
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Affiliation(s)
- István Ilisz
- Department of Inorganic and Analytical Chemistry, University of Szeged, Dóm tér 7, H-6720 Szeged, Hungary
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8
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Determination of l- and d-carnitine in dietary food supplements using capillary electrophoresis–tandem mass spectrometry. Food Chem 2010. [DOI: 10.1016/j.foodchem.2009.11.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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9
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Sánchez-Hernández L, García-Ruiz C, Crego AL, Marina ML. Sensitive determination of D-carnitine as enantiomeric impurity of levo-carnitine in pharmaceutical formulations by capillary electrophoresis-tandem mass spectrometry. J Pharm Biomed Anal 2010; 53:1217-23. [PMID: 20392588 DOI: 10.1016/j.jpba.2010.03.031] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2010] [Revised: 03/15/2010] [Accepted: 03/23/2010] [Indexed: 11/16/2022]
Abstract
In this work, capillary electrophoresis-electrospray ionization-tandem mass spectrometry was applied to the determination of l- and d-carnitine in pharmaceutical formulations. A simple sample treatment procedure consisting of the use of a dilution or an extraction step with water was employed prior to derivatization with 9-fluorenylmethoxycarbonyl (FMOC). The method was validated in terms of selectivity, linearity, accuracy, precision and sensitivity, with a LOD of 10ngmL(-1) for each enantiomer, which was enough to detect enantiomeric impurities up to 0.002% of d-carnitine with respect to the main enantiomer (l-carnitine). Eleven pharmaceutical formulations were analyzed including ampoules, oral solutions, sachets, and tablets. Results showed contents for carnitine comprised between 77 and 101% with respect to the labeled ones in the case of those formulations marketed with the racemate, and from 97 to 102% in those cases where the single enantiomer (l-carnitine) was employed as active ingredient. Percentages for the enantiomeric impurity (d-carnitine) ranging from 0.6 to 1.3% were obtained exceeding the limits established for impurities in drug products. These results corroborate the need of validated analytical methodologies enabling the quality control of pharmaceutical formulations containing carnitine.
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Affiliation(s)
- Laura Sánchez-Hernández
- Department of Analytical Chemistry, Faculty of Chemistry, University of Alcalá. Ctra. Madrid-Barcelona Km. 33.600, 28871 Alcalá de Henares, Madrid, Spain
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de Andrés F, Castañeda G, Ríos A. Achiral liquid chromatography with circular dichroism detection for the determination of carnitine enantiomers in dietary supplements and pharmaceutical formulations. J Pharm Biomed Anal 2009; 51:478-83. [PMID: 19303234 DOI: 10.1016/j.jpba.2009.02.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2009] [Revised: 02/12/2009] [Accepted: 02/16/2009] [Indexed: 11/17/2022]
Abstract
A simple and enantioselective method for the separation and determination of carnitine enantiomers in dietary supplements and pharmaceutical formulation samples is proposed. This method is based on achiral liquid chromatographic separation of carnitine enantiomers from interferences and direct circular dichroism (CD) detection. The calibration curve of the anisotropy factor (g) versus the enantiomeric excess was linear, with a correlation coefficient (R(2)) of 0.996. The precision evaluated by UV peak area and CD peak area was suitable (RSD <5% in all cases). The usefulness of the proposed method was demonstrated by analysing natural dietary supplements and pharmaceutical formulation samples. This method has the advantages of being rapid and precise, without using an expensive chiral column. The method was suitable for the simultaneous determination of both enantiomers and for assessing the chemical purity of carnitine.
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Affiliation(s)
- Fernando de Andrés
- Department of Analytical Chemistry and Food Technology, Faculty of Chemistry, University of Castilla-La Mancha, Av. Camilo José Cela, 10. E-13004 Ciudad Real, Spain
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Castro-Puyana M, García-Ruiz C, Crego AL, Marina ML. Development of a CE-MS2method for the enantiomeric separation of L/D-carnitine: Application to the analysis of infant formulas. Electrophoresis 2009; 30:337-48. [DOI: 10.1002/elps.200800163] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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12
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Cho SH, Lee J, Lee WY, Chung BC. Direct determination of acylcarnitines in amniotic fluid by column-switching liquid chromatography with electrospray tandem mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2006; 20:1741-6. [PMID: 16676311 DOI: 10.1002/rcm.2504] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
A direct, simple, and simultaneous determination of acylcarnitines in amniotic fluid was developed using column-switching liquid chromatography/tandem mass spectrometry (LC/MS/MS). The analytes can be assayed within 20 min without any sample preparation process, and we monitored separated acylcarnitines with positive electrospray ionization (ESI)-MS/MS. The calibration ranges of acylcarnitines were 1 to 100 nmol/L. The linearity of the method was 0.992 to 0.999, and the limits of detection at a signal-to-noise ratio of 3 were 1 nmol/L. The coefficients of variation were in the range of 5.2 to 13.3% for within-day variation and 6.7 to 11.9% for day-to-day, respectively. We detected acylcarnitines in the amniotic fluid of 22 women in the early stages of their pregnancies in the range of 2.2 to 17.2 nmol/L. The proposed method could be applied to diagnosis, monitoring, and biomedical investigations of inborn errors of the organic acid and fatty acid metabolism of the embryo.
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Affiliation(s)
- Sung-Hee Cho
- Bioanalysis and Biotransformation Research Center, KIST, Chengryang, Seoul 130-605, Korea
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13
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Wang CY, Wang DH, Leng TH, Yu QS. Synthesis of a new enantiopure chiral aza crown ether and its application in enantiomeric separation. J Heterocycl Chem 2005. [DOI: 10.1002/jhet.5570420602] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Prokorátová V, Kvasnicka F, Sevcík R, Voldrich M. Capillary electrophoresis determination of carnitine in food supplements. J Chromatogr A 2005; 1081:60-4. [PMID: 16013599 DOI: 10.1016/j.chroma.2005.03.033] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
L-Carnitine is a substance natural for human body which transfers fatty acids to the place of burning-mitochondria and aids the transformation of fats into energy and this way supports overweight reduction and immediate physical performance, increases resistance from physical load and protect heart from overload. In this study are described newly developed electrophoretic methods (ITP, CZE with direct and/or indirect UV detection) for carnitine determination in various samples. The results were compared with results obtained by validated HPLC method. All of these methods gave comparable results. The detection limits of the electrophoretic methods were between 2.4 and 4.7 microg/ml, reproducibility (relative standard deviation, RSD%) was between 1.2 and 4.4% and recoveries were between 91 and 113% in different samples. The shorter analysis and low running cost are the main advantages of CE methods.
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Affiliation(s)
- Vendula Prokorátová
- Institute of Chemical Technology, Department of Food Preservation and Meat Technology, Technicá 5, 166 28 Prague 6, Czech Republic
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15
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HPLC of Amino Acids as Chloroformate Derivatives. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/s0301-4770(05)80009-0] [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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16
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Katoh A, Yamamoto R, Fujimoto T, Saito R. High-Performance Liquid Chromatographic Enantioseparation Based on Diastereomer Formation with New Fluorescent Chiral Quinoxalines. HETEROCYCLES 2005. [DOI: 10.3987/com-05-10346] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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17
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D'Acquarica I, Gasparrini F, Giannoli B, Badaloni E, Galletti B, Giorgi F, Tinti MO, Vigevani A. Enantio- and chemo-selective HPLC separations by chiral–achiral tandem-columns approach: the combination of CHIROBIOTIC TAG™ and SCX columns for the analysis of propionyl carnitine and related impurities. J Chromatogr A 2004; 1061:167-73. [PMID: 15641359 DOI: 10.1016/j.chroma.2004.11.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
We describe a new tandem-columns chiral-achiral HPLC arrangement by using a chiral column (CHIROBIOTIC TAG) connected in series with an achiral column (Spherisorb S5 SCX), based on a strong cationic exchange mechanism; this approach is very useful for the analysis of chiral molecules, containing cationic groups in their structures. We used this special combination to develop an easy and convenient procedure for the enantio- and chemo-selective dosage of propionyl L-carnitine (1) and relative impurities (2-6), which allowed for the simultaneous separation and quantitation within 30 min. Under the best chromatographic conditions (acetonitrile-10 mM sodium dihydrogen phosphate 65:35, v/v (pHa 6.80) as the mobile phase and UV detection at 205 nm], all the individual peaks were well separated. The applicability of the method, fully validated, was demonstrated by the analysis of a pharmaceutical batch of propionyl L-carnitine, where we found the following contents: 98.5% for 1 (drug substance); 0.15% for 3; 0.1% for 5 and 0.2% for 6. The enantiomeric excess (e.e.%) measured for the drug substance was 98.9%. Finally, a single mixed-bed column, packed with a binary mixture of the chiral and achiral phases, in a 1:1 ratio, gave similar chromatographic results as the tandem-columns approach, and thus, offered an easy alternative solution to the separation of the considered mixture.
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Affiliation(s)
- Ilaria D'Acquarica
- Dipartimento di Studi di Chimica e Tecnologia delle Sostanze Biologicamente Attive, Università La Sapienza, Ple Aldo Moro 5, 00185 Roma, Italy
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18
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Toyo'oka T. Resolution of chiral drugs by liquid chromatography based upon diastereomer formation with chiral derivatization reagents. JOURNAL OF BIOCHEMICAL AND BIOPHYSICAL METHODS 2002; 54:25-56. [PMID: 12543490 DOI: 10.1016/s0165-022x(02)00127-6] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Chiral derivatization reagents for resolution of biologically important compounds, such as chiral drugs by high-performance liquid chromatography (HPLC), based upon pre-column derivatization and diastereomer formation, are reviewed. The derivatization reagents for various functional groups, i.e., amine, carboxyl, carbonyl, hydroxyl and thiol, are evaluated in terms of reactivity, stability, wavelength, handling, versatility, sensitivity, and selectivity. The applicability of the reagents to the analyses of drugs and bioactive compounds are included in the text.
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Affiliation(s)
- Toshimasa Toyo'oka
- School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, Japan.
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Freimüller S, Altorfer H. A chiral HPLC method for the determination of low amounts of D-carnitine in L-carnitine after derivatization with (+)-FLEC. J Pharm Biomed Anal 2002; 30:209-218. [PMID: 12191705 DOI: 10.1016/s0731-7085(02)00341-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
An indirect enantioseparation method for robust and precise determination of D-Carnitine (D-C) in L-Carnitine (L-C) in the range of 0.1-1.0% is presented. The method is based on derivatization of Carnitine with (+)-[1-(9-fluorenyl)-ethyl]-chloroformate ((+)-FLEC). The two diastereomers are subsequently separated of on an octadecyl column using detection of the eluent by fluorescence (260 excitation, 310 nm emission monitoring). This procedure can be calibrated conveniently by diluting the derivatization solution of the sample. Hence, D-C was determined indirectly through quantification of L-C thereby strongly increasing the robustness and reducing the costs. During the development of the method a study was undertaken to prove that the method is suitable to determine enantiomeric purity of L-C indeed. Moreover, the method was validated according to the ICH guidance, which required the additional performance of a collaborative study. The proposed assay can be carried out using an autoinjector because the derivatives are very stable. Hence, we believe that this method will become popular for reliable determination of enantiomeric purity of L-C.
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Affiliation(s)
- Sascha Freimüller
- Institute of Pharmaceutical Sciences, Federal Institute of Technology (ETH), 117 M48 Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
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20
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TOYO'OKA T. Analytical Chemistry related to Biofunctional Research. Development of chiral derivatization reagents having benzofurazan (2,1,3-benzoxadiazole) fluorophore for HPLC analysis and their application to the sensitive detection of biologically important compounds. BUNSEKI KAGAKU 2002. [DOI: 10.2116/bunsekikagaku.51.339] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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21
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Nakaya KI, Tanaka T, Shirataki Y, Shiozaki H, Funabiki K, Shibata K, Matsui M. 4-(2-Aminoethylamino)-7H-benz[de]benzimidazo[2,1-a]isoquinoline-7-one as a Highly Sensitive Fluorescent Labeling Reagent for Carnitine. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2001. [DOI: 10.1246/bcsj.74.173] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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22
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Vernez L, Thormann W, Krähenbühl S. Analysis of carnitine and acylcarnitines in urine by capillary electrophoresis. J Chromatogr A 2000; 895:309-16. [PMID: 11105876 DOI: 10.1016/s0021-9673(00)00703-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A capillary electrophoresis method is described for the simultaneous analysis of carnitine and short-chain acylcarnitines in aqueous standard solutions and urine samples. Samples were worked up using silica gel extraction and derivatization with 4'-bromophenacyl trifluoromethanesulfonate. Separation was performed in less than 8 min using a binary buffer system containing phosphate/phosphoric acid and sodium dodecyl sulfate. 3-(2,2,2-Trimethylhydrazinium)propionate (mildronate) was used as an internal standard. The method was developed with aqueous standard solutions and then applied successfully to spiked and unspiked human urine samples. The limit of detection for both carnitine and acetylcamitine is 3 microM.
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Affiliation(s)
- L Vernez
- Department of Clinical Pharmacology, University of Berne, Switzerland
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23
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Affiliation(s)
- R Vespalec
- Institute of Analytical Chemistry, Czech Academy of Sciences, Veverí 97, CZ-611 42 Brno, Czech Republic
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24
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Manjón A, Obón JM, Iborra JL. Determination of L-carnitine by flow injection analysis with NADH fluorescence detection. Anal Biochem 2000; 281:176-81. [PMID: 10870832 DOI: 10.1006/abio.2000.4573] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A flow injection analysis method for determining L-carnitine is reported. The system uses the enzyme L-carnitine dehydrogenase covalently immobilized to Eupergit C. The NADH produced by the action of the enzyme, which is proportional to the L-carnitine concentration, is quantified using fluorescence detection. The system response was rapid and had a wide range of linearity. At a flow rate of 0.2 ml/min, a detection limit of 1 microM (20 pmol) was obtained for L-carnitine, peak areas were linear up to 100 microM, and samples could be injected every 4 min. The method performed well as a routine assay, showing high sensitivity (54,000 AU/microM), a precision of 0.96%, and the ability to carry out 144 consecutive assays with an RSD of 1.47% (good stability). Comparisons were made with other known methods for L-carnitine determination. Presence of D-carnitine had no effect on L-carnitine assay. The analysis was valid for determining L-carnitine concentrations in commercial pharmaceutical preparations.
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Affiliation(s)
- A Manjón
- Department of Biochemistry and Molecular Biology B, Faculty of Chemistry, University of Murcia, Spain.
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25
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Chen Z, Warsinke A, Gajovic N, Groβe S, Hu J, Kleber HP, Scheller FW. A D-Carnitine Dehydrogenase Electrode For The Assessment Of Enantiomeric Purity Of L-Carnitine Preparations. ANAL LETT 2000. [DOI: 10.1080/00032710008543110] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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26
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Heinig K, Henion J. Determination of carnitine and acylcarnitines in biological samples by capillary electrophoresis-mass spectrometry. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1999; 735:171-88. [PMID: 10670733 DOI: 10.1016/s0378-4347(99)00417-x] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Free carnitine and acylcarnitines (carnitine esters) play an important role in the metabolism of fatty acids. Metabolic disorders can be detected by abnormal levels of these compounds in biological fluids. Capillary electrophoresis-mass spectrometry has the advantage of combining an efficient separation technique with highly selective detection. Therefore, we have developed a method for the determination of carnitine and several of its esters implementing electrospray capillary electrophoresis-mass spectrometry in the positive ion selected reaction monitoring mode. A sheath-flow interface with a mixture of 2-propanol or methanol, water and acetic acid as sheath liquid and nitrogen as nebulizing gas was used. The zwitterionic analytes migrated as cations in the applied electric field using ammonium acetate-acetic acid or formic acid electrolytes. Separations were performed in aqueous, mixed organic-aqueous and non-aqueous media. The influence of the electrolyte composition on the separation efficiency was investigated. The electrospray conditions have been optimized regarding ion current stability and sensitivity. Ammonium acetate (10 mmol/l)-0.8% formic acid in water or 6.4% formic acid in acetonitrile-water (1:1) were used as running buffers for the determination of carnitine and acylcarnitines in human biological samples. Methanol extracts of dried blood spots were analyzed as well as urine and plasma following sample preparation via solid-phase or liquid-liquid extraction. Recoveries approaching 100% were achieved depending on the analytes and sample preparation procedures employed. Endogenous carnitine and acetylcarnitine were determined at concentrations between 2.7 and 108 nmol/ml in normal human urine and plasma. Other acylcarnitines were detected at levels of below the limit of detection to 12 nmol/ml. Good precision (0.8 to 14%) and accuracy (85 to 111%) were obtained; the achieved limits of quantitation (0.1 to 1 nmol/ml) are sufficient to characterize carnitine and acylcarnitine levels occurring as markers for metabolic disorders.
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Affiliation(s)
- K Heinig
- Analytical Toxicology, Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14850, USA
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27
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Obón JM, Buendía B, Cánovas M, Iborra JL. Enzymatic cycling assay for D-carnitine determination. Anal Biochem 1999; 274:34-9. [PMID: 10527494 DOI: 10.1006/abio.1999.4233] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
An enzymatic method for d-carnitine determination using the enzyme d-carnitine dehydrogenase is described. The assay is based on the amplified signal produced during NAD(+) cycling in the presence of a tetrazolium salt and using phenazine methosulfate as electron carrier. Optimum assay conditions were studied with two tetrazolium salt pairs: 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT)/MTT-formazan and 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-phenyl tetrazolium chloride (INT)/INT-formazan. The first pair (MTT) showed higher sensitivity. The calibration curve was linear from 0.1 to 5 mM d-carnitine, with a quantification limit of 0.1 mM and a relative standard deviation of 1.51%. The procedure is simple, rapid, accurate, and easily automated. It was satisfactorily applied to following d-carnitine levels during the microbial transformation of d-carnitine into l-carnitine and to determining the d-carnitine content of pharmaceutical preparations.
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Affiliation(s)
- J M Obón
- Department of Biochemistry and Molecular Biology B, Faculty of Chemistry, University of Murcia, Murcia, E-30100, Spain
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28
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D'Acquarica I, Gasparrini F, Misiti D, Villani C, Carotti A, Cellamare S, Muck S. Direct chromatographic resolution of carnitine and O-acylcarnitine enantiomers on a teicoplanin-bonded chiral stationary phase. J Chromatogr A 1999; 857:145-55. [PMID: 10536833 DOI: 10.1016/s0021-9673(99)00773-6] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
R-(-)-Carnitine (vitamin B(T)) plays an important role in human energy metabolism, by facilitating the transport of long-chained fatty acids across the mitochondrial membranes. Its (S)-enantiomer acts as a competitive inhibitor of carnitine acetyltransferase, causing depletion of the body R-(-)-carnitine stock. Consequently, the separation of carnitine enantiomers is very important both to study their biological activities and to control the enantiomeric purity of pharmaceutical formulations. In the present paper we describe an easy, fast and convenient procedure for the separation of the enantiomers of carnitine and O-acylcarnitines by enantioselective HPLC on a laboratory-made chiral column containing covalently bonded teicoplanin as selector. High enantioselectivity factors (alpha values ranging from 1.31 to 3.02) and short-time analyses characterize the analytical procedure; in addition, analytes are easily detected by evaporative light scattering with no need for preliminary derivatization. The effects of pH and ionic strength of the mobile phase and of the nature of the organic modifier on the enantioselective separations were also investigated.
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Affiliation(s)
- I D'Acquarica
- Dipartimento di Studi di Chimica e Tecnologia delle Sostanze Biologicamente Attive, Università La Sapienza, Rome, Italy
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29
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Abstract
The marked increase in the number of communications on the utilization of electrophoresis for practical chiral separations within the last three years is the most evident, and the most important fact. It reveals that the basic period of intensive research in the field is finished. The search for chiral selectors discriminating racemates in a reasonably analytical manner and the study of both the mechanism and physicochemical aspects of the chiral discrimination process were the main features of that period. Here, we review the state of the art in the field and state the references of the related literature up to the end of 1998.
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Affiliation(s)
- R Vespalec
- Institute of Analytical Chemistry, Academy of Sciences, Brno, Czech Republic
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30
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Mardones C, Ríos A, Valcárcel M, Cicciarelli R. Enantiomeric separation of D- and L-carnitine by integrating on-line derivatization with capillary zone electrophoresis. J Chromatogr A 1999; 849:609-16. [PMID: 10457455 DOI: 10.1016/s0021-9673(99)00602-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
A new capillary zone electrophoretic method has been developed for the enantiomeric separation and quantification of enantiomers of carnitine, D- and L-carnitine were derivatized with 9-fluorenylmethyl chloroformate in a flow system, working on-line with the capillary electrophoretic equipment. The separation was performed using a selective chiral buffer containing 2,6-dimethyl-beta-cyclodextrin (heptakis). Triethanolamine was used as electroosmotic modifier and the separation was carried out in a uncoated capillary. Under the optimal conditions the resolution between D- and L-carnitine was 1.2 and the limits of detection for both isomers were about 5.0 microM. The proposed method was applied to the determination of D-carnitine in excess of L-carnitine in synthetic samples, and the results demonstrated that the maximal D-:L-carnitine ratio determined was approximately 1:100.
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Affiliation(s)
- C Mardones
- Department of Analytical Chemistry, Faculty of Sciences, University of Cordoba, Spain
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31
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Arai T. Chiral separation of pharmaceuticals possessing a carboxy moiety. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1998; 717:295-311. [PMID: 9832251 DOI: 10.1016/s0378-4347(98)00246-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
The separation of carboxylic enantiomers in the pharmaceutical field using high-performance liquid chromatographic and capillary electrophoretic techniques is reviewed. The techniques used for chiral separation include diastereomer derivatization, a chiral mobile phase, a chiral stationary phase (high-performance liquid chromatography) and chiral additives (capillary electrophoresis). Practical and conventional separation systems for pharmaceutical applications, such as pharmacokinetics, optical purity testing and stability studies, are described. A comprehensive collection of applications to carboxylic drugs and other carboxylic compounds of pharmaceutical interest is listed in the tables. The characteristics of each enantioseparation method are also discussed briefly.
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Affiliation(s)
- T Arai
- Medical Development Department, Daiichi Pharmaceutical Co., Ltd., Tokyo, Japan
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32
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Bardelmeijer HA, Lingeman H, de Ruiter C, Underberg WJ. Derivatization in capillary electrophoresis. J Chromatogr A 1998; 807:3-26. [PMID: 9646486 DOI: 10.1016/s0021-9673(98)00230-1] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In recent years capillary electrophoresis (CE) has been developed into a versatile separation technique, next to gas and liquid chromatography (LC), well suited for the determination of a wide variety of e.g., pharmaceutical, biomedical and environmental samples. The main advantages of CE over chromatographic separation techniques are its simplicity and efficiency. It is well recognized, however, that the sensitivity and selectivity of the detection are relatively weak points of CE. One way to overcome these limitations is the conversion (derivatization) of the analytes into product(s) with more favourable detection characteristics. Although, in principle, almost any detection mode can be combined with a derivatization procedure, in practice, fluorescence monitoring is favoured in most cases. This paper aims to give a short overview on the various reagents that can be used for pre-, post- and on-column derivatization in CE. First, a short introduction is given on CE as an analytical technique, followed by a discussion of the pros and cons of the various modes of derivatization, a comparison of derivatizations in CE with derivatizations in LC, the principles of fluorescence and prerequisites for a good fluorophore and the potential of using diode lasers in combination with a labelling procedure. With respect to the derivatization reagents the emphasis is on the labelling of amino, aldehyde, keto, carboxyl, hydroxyl and sulfhydryl groups.
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Affiliation(s)
- H A Bardelmeijer
- Utrecht University, Faculty of Pharmacy, Department of Pharmaceutical Analysis, Netherlands
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33
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Fanali S, Aturki Z, Desiderio C. New strategies for chiral analysis of drugs by capillary electrophoresis. Forensic Sci Int 1998. [DOI: 10.1016/s0379-0738(98)00013-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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34
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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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35
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36
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Hansen SH, Bjørnsdottir I, Tjørnelund J. Separation of cationic cis–trans (Z–E) isomers and diastereoisomers using non-aqueous capillary electrophoresis. J Chromatogr A 1997. [DOI: 10.1016/s0021-9673(97)00846-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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37
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Bardelmeijer HA, Waterval JC, Lingeman H, van't Hof R, Bult A, Underberg WJ. Pre-, on- and post-column derivatization in capillary electrophoresis. Electrophoresis 1997; 18:2214-27. [PMID: 9456036 DOI: 10.1002/elps.1150181212] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
This survey gives a short overview of the various reagents and procedures that can be used for pre-, post- and on-column derivatization in capillary electrophoresis. First there is an introduction about capillary electrophoresis as an analytical technique; this is followed by a discussion of the pros and cons of the various modes of derivatization and a comparison with liquid chromatography. In the following paragraphs the reagents for a number of functional groups are discussed. The emphasis is on derivatization of the amino group. Most of the information on the reagents and derivatization procedures is listed in tables together with information on the detection mode, analytes, sensitivity and samples. In addition to the amino group, information is given on labeling of aldehyde, keto, carboxyl, hydroxyl and sulfhydryl groups.
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Affiliation(s)
- H A Bardelmeijer
- Department of Pharmaceutical Analysis, Utrecht University, The Netherlands
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38
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39
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Vespalec R, Bocek P. Chiral separations by capillary zone electrophoresis: present state of the art. Electrophoresis 1997; 18:843-52. [PMID: 9221870 DOI: 10.1002/elps.1150180603] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- R Vespalec
- Institute of Analytical Chemistry, Czech Academy of Sciences, Brno, Czech Republic
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40
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Skanchy DJ, Wilson R, Poh T, Xie GH, Demarest CW, Stobaugh JF. Resolution of acylated dipeptide stereoisomers by capillary electrophoresis using sulfobutylether derivatized beta-cyclodextrin. Electrophoresis 1997; 18:985-95. [PMID: 9221888 DOI: 10.1002/elps.1150180621] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The separation of enantiomerically and diastereomerically related stereoisomers of acylated Asp-Phe dipeptides was explored using capillary electrophoresis (CE). This series of dipeptides included the alpha-L,L parent compound and the three other potential Asp containing stereoisomers (alpha-D,D, alpha-L,D, and alpha-D,L), as well the four possible isoAsp containing stereoisomers (beta-L,L, beta-D,D, beta-L,D and beta-D,L). The separation of these substances was explored using both neutral and charged cyclodextrins as the stereoisomer selector added to the running electrolyte. The major experimental parameters investigated included pH, the cyclodextrin type, and the cyclodextrin concentration. Due to differences in the pKa values of the carboxylic acid groups, adjustment of the separation buffer to between pH 3.0 and 4.0 provided for sufficient electrophoretic mobility differences to result in excellent separations of the diastereomerically related peptides in this pH region. The resolution of the enantiomerically related peptide stereoisomers was accomplished using low concentrations (1 mM) of the anionic cyclodextrin derivative, sulfobutylether-beta-cyclodextrin (SBE-beta-CD). This negatively charged cyclodextrin was found to be superior for the resolution of the enantiomerically related peptides as compared to native beta-cyclodextrin or the neutral derivatives, dimethyl beta-cyclodextrin and hydroxypropyl beta-cyclodextrin. An alternative approach using anionic or neutral surfactants in conjunction with the SBE-beta-CDs was also explored and found to be successful but problematic.
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Affiliation(s)
- D J Skanchy
- Department of Pharmaceutical Chemistry, Center of Bioanalytical Research, University of Kansas, Lawrence 66047, USA
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41
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Bojarski J, Aboul-Enein HY. Application of capillary electrophoresis for the analysis of chiral drugs in biological fluids. Electrophoresis 1997; 18:965-9. [PMID: 9221885 DOI: 10.1002/elps.1150180618] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- J Bojarski
- Department of Organic Chemistry, College of Medicine, Jagiellonian University, Krakow, Poland
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42
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Synthesis of new stable aliphatic isothiocyanate-based chiral derivatizing agent and application to indirect separation of chiral amino and thiol compounds. Chromatographia 1997. [DOI: 10.1007/bf02466738] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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43
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Hanschmann H, Kleber HP. Purification and characterization of D(+)-carnitine dehydrogenase from Agrobacterium sp.--a new enzyme of carnitine metabolism. BIOCHIMICA ET BIOPHYSICA ACTA 1997; 1337:133-42. [PMID: 9003445 DOI: 10.1016/s0167-4838(96)00161-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
D(+)-Carnitine dehydrogenase from Agrobacterium sp. catalyzes the oxidation of D(+)-carnitine to 3-dehydrocarnitine as initial step of D(+)-carnitine degradation. The NAD(+)-specific, cytosolic enzyme was purified 126-fold to apparent electrophoretic homogeneity by 4 chromatographic steps. The molecular mass of the native enzyme was estimated to be 88 kDa by size-exclusion chromatography. It seems to be composed of 3 identical subunits with a relative molecular mass of 28 kDa as found by sodium dodecyl sulfate polyacrylamide gel electrophoresis and laser-induced mass spectrometry. The isoelectric point was found to be 4.7-5.0. The optimum temperature is 37 degrees C and the optimum pH for the oxidation and the reduction reaction are 9.0-9.5 and 5.5-6.5, respectively. The purified enzyme was further characterized with respect to substrate specificity, kinetic parameters and amino terminal sequence. Analogues of D(+)-carnitine (L(-)-carnitine, crotonobetaine, gamma-butyrobetaine, carnitine amide, glycine betaine, choline) are competitive inhibitors of D(+)-carnitine oxidation. The equilibrium constant of the reaction of D(+)-carnitine dehydrogenase was determined to be 2.2 x 10(-12). The purified D(+)-carnitine dehydrogenase has similar kinetic properties to the L(-)-carnitine dehydrogenase from the same microorganism as well as to L(-)-carnitine dehydrogenases of other bacteria.
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Affiliation(s)
- H Hanschmann
- Institut für Biochemie, Fakultät für Biowissenschaften, Pharmazie und Psychologie, Universität Leipzig, Germany
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44
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Bressolle F, Audran M, Pham TN, Vallon JJ. Cyclodextrins and enantiomeric separations of drugs by liquid chromatography and capillary electrophoresis: basic principles and new developments. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL APPLICATIONS 1996; 687:303-36. [PMID: 9017455 DOI: 10.1016/s0378-4347(96)00263-0] [Citation(s) in RCA: 146] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Investigation of individual drug enantiomers is required in pharmacokinetic and pharmacodynamic studies of drugs with a chiral centre. Cyclodextrins (CDs) are extensively used in high-performance liquid chromatography as stationary phases bonded to a solid support or as mobile phase additives in HPLC and capillary electrophoresis (CE) for the separation of chiral compounds. We describe here the basis for the liquid chromatographic and capillary electrophoretic resolution of drug enantiomers and the factors affecting their enantiomeric separation. This review covers the use of CDs and some of their derivatives in studies of compounds of pharmacological interest.
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Affiliation(s)
- F Bressolle
- Laboratoire de Pharmacocinetique, Faculté de Pharmacie, Université de Montpellier I, France
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45
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Toyo'oka T. Recent progress in liquid chromatographic enantioseparation based upon diastereomer formation with fluorescent chiral derivatization reagents. Biomed Chromatogr 1996; 10:265-77. [PMID: 8949907 DOI: 10.1002/(sici)1099-0801(199611)10:6<265::aid-bmc602>3.0.co;2-a] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Techniques for the resolution by liquid chromatography of racemic compounds based upon diastereomer formation with a fluorescent chiral reagent are outlined in this review. The tagging reagents for various functional groups, i.e. amine, carboxyl, hydroxyl and thiol, are evaluated in terms of optical purity, handling, flexibility, stability, sensitivity and selectivity. The applicabilities of the reagents to drugs and biologically important substances are included in the text. This review is limited to reagents with fluorophores and reagents that exhibit fluorescence.
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Affiliation(s)
- T Toyo'oka
- Department of Analytical Chemistry, School of Pharmaceutical Sciences, University of Shizuoka, Japan
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46
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Abstract
The principles and applications of chromatographic separation of enantiomers in pharmaceutical analysis have been reviewed. Several of recently reported enantioselective analysis of various racemic drugs using both the 'indirect' and 'direct' methods have been presented.
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Affiliation(s)
- J Bojarski
- Department of Organic Chemistry, College of Medicine, Jagiellonian University, Krakow, Poland
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47
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48
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Abstract
Separation of optical isomers of compounds of pharmaceutical interest by capillary electrophoretic techniques is reviewed. The direct and indirect separation method, as well as the main resolution mechanisms and the parameters influencing the stereoselectivity are discussed considering capillary zone electrophoresis, micellar electrokinetic chromatography, isotachophoresis and electrochromatography. Several chiral selectors have been successfully used in CE for chiral separation, including cyclodextrins and their derivatives, modified crown-ethers, proteins, antibiotics, linear saccharides and chiral surfactants. Only applications in the pharmaceutical field with the most important experimental conditions are summarised in the Tables reported in this paper. The chiral analyses of drugs in real samples like biological fluids or pharmaceutical formulations are also reported.
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Affiliation(s)
- S Fanali
- Istituto di Cromatografia del C.N.R., Area della Ricerca di Roma, Italy
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49
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Ballesteros E, Gallego M, Valcárcel M. Sequential Determination of d- and l-Glutamic Acid by Continuous Fractional Crystallization. Anal Chem 1996. [DOI: 10.1021/ac9506591] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Evaristo Ballesteros
- Department of Analytical Chemistry, Faculty of Sciences, University of Córdoba, E-14004 Córdoba, Spain
| | - Mercedes Gallego
- Department of Analytical Chemistry, Faculty of Sciences, University of Córdoba, E-14004 Córdoba, Spain
| | - Miguel Valcárcel
- Department of Analytical Chemistry, Faculty of Sciences, University of Córdoba, E-14004 Córdoba, Spain
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