Chiral separation of intact amino acids by capillary electrophoresis-mass spectrometry employing a partial filling technique with a crown ether carboxylic acid

Lee, Sul; Kim, Sujin; Bang, Eunjung; Na, Yun-Cheol

doi:10.1016/j.chroma.2018.12.001

Cited by 40 publications

(31 citation statements)

References 38 publications

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“…To determine d ‐AA in vinegars, Lee et al developed a CE‐MS method for the enantiomeric separation of underivatized free AAs [41]. This work made use of a sheath‐liquid interface for the coupling of CE to MS and a separation buffer that consisted of 30 mM (18‐crown‐6)‐2,3,11,12‐tretracarboxylic acid (18C6H4), used as a chiral selector (CS).…”

Section: Applicationsmentioning

confidence: 99%

CE‐MS for metabolomics: Developments and applications in the period 2018–2020

Zhang

Ramautar

2020

Electrophoresis

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Capillary electrophoresis‐mass spectrometry (CE‐MS) is now a mature analytical technique in metabolomics, notably for the efficient profiling of polar and charged metabolites. Over the past few years, (further) progress has been made in the design of improved interfacing techniques for coupling CE to MS; also, in the development of CE‐MS approaches for profiling metabolites in volume‐restricted samples, and in strategies that further enhance the metabolic coverage. In this article, which is a follow‐up of a previous review article covering the years 2016–2018 (Electrophoresis 2019, 40, 165–179), the main (technological) developments in CE‐MS methods and strategies for metabolomics are discussed covering the literature from July 2018 to June 2020. Representative examples highlight the utility of CE‐MS in the fields of biomedical, clinical, microbial, plant and food metabolomics. A complete overview of recent CE‐MS‐based metabolomics studies is given in a table, which provides information on sample type and pretreatment, capillary coatings, and MS detection mode. Finally, some general conclusions and perspectives are given.

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Section: Applicationsmentioning

confidence: 99%

CE‐MS for metabolomics: Developments and applications in the period 2018–2020

Zhang

Ramautar

2020

Electrophoresis

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“…Additionally, a chiral tandem LC-MS/MS system was developed for the high-sensitivity, even at sub-femtomole levels, and high-selectivity determination of chiral amino acids, requiring approximately 20 min per sample. Compared with conventional methods [17][18][19][20] , this system was adopted to separate the molecular species of enantiomeric amino acids (all proteinogenic amino acids and non-proteinogenic amino acids such as Cit and Orn) with high-throughput for application to blood samples in addition to chiral amino acid standards. A previous study showed that chromatographic separation of DL-Ala, DL-Asp, and DL-Ser could be achieved by AQC derivatisation using a single ZWIX column 21 .…”

Section: Discussionmentioning

confidence: 99%

“…In comparison, although the one-dimensional method is applicable as a diagnosis assay, simultaneous separation of both molecular species and enantiomers (e.g., complete enantiomer separation of secondary amines such as racemic proline (DL-Pro)) has not been achieved and the low-precision of chiral amino acid analysis has been noted 19 . In addition, it is often difficult to simultaneously separate all proteinogenic chiral amino acids (especially, DL-Pro) by capillary electrophoresis-mass spectrometry 20 .…”

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confidence: 99%

Development of a cognitive function marker based on D-amino acid proportions using new chiral tandem LC-MS/MS systems

Kimura

Tsujimura

Tsuchiya

et al. 2020

Sci Rep

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the incidence of dementia, a clinical symptom characterized by severe cognitive decline, is increasing worldwide. Predictive biomarkers are therefore required for early identification and management. D-amino acids in the brain contribute to cognitive function and are suggested as useful biomarkers for diagnosing dementia risk. to clarify their relationship with human cognitive decline, we developed an identification method of chiral metabolomics for detecting slight differences in chiral amino acid amounts. chiral tandem liquid chromatography-tandem mass spectrometry systems were applied for sensitive and selective amino acid species along with chiral species determination based on anion and zwitterion exchange mechanisms. in a comprehensive health cohort (cross-sectional study), we measured blood chiral amino acid levels from 305 women (65-80 years old) classified into Control, Mild-cognitive-impairment (Mci), and Dementia groups using the Mini-Mental State examination. Mci exhibited higher D-pro (D-pro/(D-pro + L-pro)) proportion vs the control group, suggesting this proportion as a useful biomarker for Mci. Biomarker accuracy was improved in combination with D-Ser proportion. Receiver operating characteristics analysis of the control vs. Mci proportion obtained area under the curve (0.80) with 70% sensitivity and 84% specificity at the optimal cutoff value (0.30). Thus, dementia monitoring can be improved by including trace D-amino acids measurements. Dementia is a clinical symptom indicating a type of cognitive dysfunction that, when severe, leads to increasing dependence on others in aspects of daily living. Various types of dementia include Alzheimer (AD), cerebrovascular, Lewy body, and frontotemporal dementia. The detailed cause of onset has not yet been elucidated and no effective biomarkers are available for the early diagnosis of dementia or selection of therapeutic agents 1. The prodromal stage of dementia and mild cognitive impairment (MCI) have attracted attention in recent years as early stages of cognitive decline. It has been reported that approximately 10% of MCI converts to AD annually 2. Moreover, 14-44% of patients with MCI improve to the status of healthy elderly individuals through early interventions 3. Therefore, the early diagnosis of dementia risk and timely interventions, such as nutrition, exercise, and sleep, are desired to prevent cognitive decline in the at-risk elderly population. Current methods of diagnosis require a wide range of clinical tests including cognitive performance assessment, genetic screening, measurement of amyloid beta and tau proteins in the liquor cerebrosinalis, brain imaging, and behavioural assessments 4. Especially in recent years, numerous researchers have aimed to identify appropriate markers measurable in the blood for the early identification and management of dementia. For example, quantitative measurements of amyloid beta and its sequester protein in the blood have been developed 5-9. However, these biomarkers are difficult to apply toward practical d...

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“…For instance, Sánchez-López et al developed a chiral EKC methodology with ion trap MS (EKC-IT-MS) for quality control of the commercialized single-isomer duloxetine, where the nonvolatile (2-hydroxypropyl)-β-CD was prevented from entering the mass spectrometer by introducing a selector plug of 38% of the total capillary length [79]. In another study by Lee et al, native amino acids were separated employing (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid in an aqueous buffer using a selector plug that filled 70% of the capillary [278]. Enantiomers were identified by quadrupole TOF/MS and no peaks corresponding to the chiral selector were observed.…”

Section: Partial-filling Techniquementioning

confidence: 99%

Past, present, and future developments in enantioselective analysis using capillary electromigration techniques

2020

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Past, present, and future developments in enantioselective analysis using capillary electromigration techniques Enantioseparation of chiral products has become increasingly important in a large diversity of academic and industrial applications. The separation of chiral compounds is inherently challenging and thus requires a suitable analytical technique that can achieve high resolution and sensitivity. In this context, CE has shown remarkable results so far. Chiral CE offers an orthogonal enantioselectivity and is typically considered less costly than chromatographic techniques, since only minute amounts of chiral selectors are needed. Several CE approaches have been developed for chiral analysis, including chiral EKC and chiral CEC. Enantioseparations by EKC benefit from the wide variety of possible pseudostationary phases that can be employed. Chiral CEC, on the other hand, combines chromatographic separation principles with the bulk fluid movement of CE, benefitting from reduced band broadening as compared to pressure-driven systems. Although UV detection is conventionally used for these approaches, MS can also be considered. CE-MS represents a promising alternative due to the increased sensitivity and selectivity, enabling the chiral analysis of complex samples. The potential contamination of the MS ion source in EKC-MS can be overcome using partial-filling and counter-migration techniques. However, chiral analysis using monolithic and open-tubular CEC-MS awaits additional method validation and a dedicated commercial interface. Further efforts in chiral CE are expected toward the improvement of existing techniques, the development of novel pseudostationary phases, and establishing the use of chiral ionic liquids, molecular imprinted polymers, and metalorganic frameworks. These developments will certainly foster the adoption of CE(-MS) as a well-established technique in routine chiral analysis.

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Chiral separation of intact amino acids by capillary electrophoresis-mass spectrometry employing a partial filling technique with a crown ether carboxylic acid

Cited by 40 publications

References 38 publications

CE‐MS for metabolomics: Developments and applications in the period 2018–2020

CE‐MS for metabolomics: Developments and applications in the period 2018–2020

Development of a cognitive function marker based on D-amino acid proportions using new chiral tandem LC-MS/MS systems

Past, present, and future developments in enantioselective analysis using capillary electromigration techniques

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