Enantiomeric purity determination of acetyl-l-carnitine by reversed-phase high-performance liquid chromatography using chiral derivatization

Kagawa, Miyuki; Machida, Yoshio; Nishi, Hiroyuki

doi:10.1016/s0021-9673(99)00780-3

Cited by 18 publications

(7 citation statements)

References 8 publications

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“…Samples containing L-carnitine and L-butyrylcarnitine were chemically modified to a chromophore for UV detection, using a modification of the method described by Kagawa et al (1999). Two hundred microliters of appropriately diluted sample in ethanol were added to a screwcapped vial with a Teflon seal, containing 0.2 mL of 50 mM ethyl chloroformate in chloroform, 0.2 mL of 50 mM triethylamine in chloroform, and 0.2 mL of 20 mM ␣-naphthylamine in ethanol.…”

Section: Hplc Analysismentioning

confidence: 99%

Ester synthesis from trimethylammonium alcohols in dry organic media catalyzed by immobilized Candida antarctica lipase B

Lozano

Daz

Diego

et al. 2003

Biotech & Bioengineering

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Twenty-one different organic solvents were assayed as possible reaction media for the synthesis of butyryl esters from trimethylammonium alcohols in dry conditions catalyzed by immobilized Candida antarctica lipase B. The reactions were carried out following a transesterification kinetic approach, using choline and L-carnitine as primary and secondary trimethylammonium alcohols, respectively, and vinyl butyrate as acyl donor. The synthetic activity of the enzyme was strictly dependent on the water content, the position of the hydroxyl group in the trimethylammonium molecule, and the Log P parameter of the assayed solvent. Anhydrous conditions and a high excess of vinyl butyrate over L-carnitine were necessary to synthesize butyryl-L-carnitine. The synthetic reaction rates of butyryl choline were practically 100-fold those of butyryl-L-carnitine with all the assayed solvents. In both cases, the synthetic activity of the enzyme was dependent on the hydrophobicity of the solvent, with the optimal reaction media showing a Log P parameter of between -0.5 and 0.5. In all cases, 2-methyl-2-propanol and 2-methyl-2-butanol were shown to be the best solvents for both their high synthetic activity and negligible loss of enzyme activity after 6 days.

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Section: Hplc Analysismentioning

confidence: 99%

Ester synthesis from trimethylammonium alcohols in dry organic media catalyzed by immobilized Candida antarctica lipase B

Lozano

Daz

Diego

et al. 2003

Biotech & Bioengineering

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“…Different derivatization reactions have been performed, as shown in Fig. 14. Derivatizing agents such as L-alanine-β-naphthylamide (ANA; Kagawa et al, 1999), BPTS, PPTS (Minkler et al, 2005a) and BMPK have been used for UV detection while 3-bromomethyl-6,7dimethoxy-1-methyl-2(1H)-quinoxalinone (BDMEQ; Kamimori and Konishi, 2001), ADAM (Kiessig and Vogt, 1997), NETS (Minkler et al, 2005b), AA and pyrene-1-carbonyl cyanide (PPC; Kamata et al, 1994) were utilized for fluorescence detection. 9-Fluorenylmethoxycarbonyl chloride (FMOC; Mardones et al, 1999a) and 1-(9-fluorenyl)ethyl chloromethane (FLEC; De Witt et al, 1994) were employed in enantiomeric determinations.…”

Section: Derivatization Reactionsmentioning

confidence: 99%

Separation of carnitine and acylcarnitines in biological samples: a review

Mansour

Wei

Danielson

2013

Biomedical Chromatography

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Carnitine and its acylesters are a family of compounds that can be used in the early diagnosis of many diseases. Carnitine and acylcarnitines have a crucial role in fatty acid transportation. The increased level of free carnitine, total carnitine, or the acylesters can act as biomarkers for many metabolic disorders, including diabetes, encephalopathy and cardiomyopathy. The determination of these compounds is difficult owing to the simple aliphatic structure, the chiral center and the permanent positive charge. Although MS detection can be enough to differentiate between some carnitine derivatives, closely related structural isomers of the acylcarnitines must be separated before detection because they form the same base peak and second most abundant ion peak. Different separation methods are discussed in this review, including reversed-phase, hydrophilic interaction, ion exchange, ion pairing, mixed mode liquid chromatography, gas chromatography and electrophoresis. Representative example chromatograms are shown. The sample preparation and the different derivatization reactions are also covered. A table that summarizes the most important analytical methods by detailing the analyte mixture, the sample matrix, the separation mode and the detection method is provided.

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“…63 For carboxylic acids, or their derivatives, of biological interest, separation of enantiomers can be achieved by using reversed-phase HPLC with an ODS column, after derivatization with alanine-b-naphthylamide. This method was used by Kagawa et al 64 to determine the enantiomeric purity of acetyl-L-carnitine, which may be important as it can stimulate actions of learning behavior and can be used as a drug. Typical chromatograms are shown in Figure 5.…”

Section: Chiral Derivatizationmentioning

confidence: 99%

Chiral Purity in Drug Analysis

Machida¹,

Nishi²

2000

Encyclopedia of Analytical Chemistry

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The preparation and evaluation of optically active compounds have become very important for the development of new drugs. The determination of chiral purity of drugs is essential in order to guarantee safety and effectiveness. Isomeric impurities may have unwanted toxicological, pharmacological, or other side‐effects. Therefore we decided to prepare an article entitled “Chiral purity in drug analysis”. This article is divided into five sections (introduction, production, regulation, evaluation methods and conclusion). In the introduction, the importance of assessing the isomeric impurities in drug analysis will be discussed. In the second section, production methods for optically active compounds, except the stereoselective synthesis method, will be summarized briefly. In particular, new trends in the production of chiral drugs, such as the simulated moving beds (SMB) method, will be described. In the third section, regulatory perspectives in the USA (Food and Drug Administration (FDA)), EC, and Japan will be described and some regulatory guidelines and guidances by, for example, the FDA, the Committee for Veterinary Medicinal Products (CVMP), and the International Conference on Harmonization (ICH) will be mentioned. In the fourth section, methods for the determination of stereoisomeric drugs will be summarized. Methods such as gas chromatography (GC), high‐performance liquid chromatography (HPLC), and capillary electrophoresis (CE) have been summarized. The focus will be on direct evaluation methods, i.e. those using chiral stationary phases (CSPs). Practical details for testing a drug's optical purity are also given.

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Enantiomeric purity determination of acetyl-l-carnitine by reversed-phase high-performance liquid chromatography using chiral derivatization

Cited by 18 publications

References 8 publications

Ester synthesis from trimethylammonium alcohols in dry organic media catalyzed by immobilized Candida antarctica lipase B

Ester synthesis from trimethylammonium alcohols in dry organic media catalyzed by immobilized Candida antarctica lipase B

Separation of carnitine and acylcarnitines in biological samples: a review

Chiral Purity in Drug Analysis

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