Homocysteine (Hcy) is incorporated into protein via a reaction of the thioester Hcy-thiolactone with ε-amino group of a protein lysine residue generating N-Hcy-protein. This reaction impairs and alters protein's function and has been implicated in atherothrombotic disease. Here, we describe new high-performance liquid chromatography assays for the determination of Hcy-thiolactone, protein N-linked Hcy, and Hcy based on an on-column derivatization with o-phthaldialdehyde and fluorescence detection. The on-column derivatization generates narrow peaks, which allows fast run times (3-5 min) and facilitates determination of N-linked Hcy directly from acid hydrolysates of plasma protein. Utility of these assays was demonstrated with human urine and plasma samples.
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http://dx.doi.org/10.1007/s00726-010-0521-7 | DOI Listing |
Anal Bioanal Chem
January 2025
Department of Chemistry - Biomedical Center, Analytical Chemistry and Neurochemistry, Uppsala University, Uppsala, Sweden.
Free fatty acids (FFAs) are important energy sources and significant for energy transport in the body. They also play a crucial role in cellular oxidative stress responses, following cell membrane depolarization, making accurate quantification of FFAs essential. This study presents a novel supercritical fluid chromatography-mass spectrometry (SFC-MS) method using selected ion recording in negative electrospray ionization mode, enabling rapid quantification of 31 FFAs within 6 min without derivatization.
View Article and Find Full Text PDFAnal Chem
July 2024
Translational Glycomics Group, Research Institute of Biomolecular and Chemical Engineering, University of Pannonia, Veszprem 8200, Hungary.
Sodium dodecyl sulfate capillary gel electrophoresis is one of the frequently used methods for size-based protein separation in molecular biology laboratories and the biopharmaceutical industry. To increase throughput, quite a few multicapillary electrophoresis systems have been recently developed, but most of them only support fluorescence detection, requiring fluorophore labeling of the sample proteins. To avoid the time-consuming derivatization reaction, we developed an on-column labeling approach utilizing propidium iodide for the first time in SDS-CGE of proteins, a dye only used before for nucleic acid analysis.
View Article and Find Full Text PDFAnal Bioanal Chem
August 2024
Chair of Analytical Chemistry and Water Chemistry, School of Natural Sciences, Department of Chemistry, Technical University of Munich, Lichtenbergstr. 4, 85748, Garching, Germany.
The continuous introduction of micropollutants into the environment through livestock farming, agricultural practices, and wastewater treatment is a major concern. Among these pollutants are synthetic sulfonamide antibiotics such as sulfamethoxazole, which are not always fully degraded and pose a risk of fostering antimicrobial resistance. It is challenging to assess the degradation of sulfonamides with conventional concentration measurements.
View Article and Find Full Text PDFTalanta
May 2024
University of Lodz, Faculty of Chemistry, Department of Environmental Chemistry, 163/165 Pomorska Str., 90-236, Łódź, Poland. Electronic address:
The report presents a new, robust, and reproducible liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and HPLC-fluorescence (FL) based methods for the determination of urinary homocysteine thiolactone (HTL). In particular, a versatile sample preparation procedure was designed to purify urine samples, involving chloroform liquid-liquid extraction (LLE) of HTL and its re-extraction (re-LLE) with formic acid, prior to chromatographic analysis. In relation to HPLC-FL assay, the quantification of HTL additionally uses o-phthaldialdehyde (OPA) as the on-column derivatization agent, while HPLC-MS/MS assay employs homoserine lactone (HSL) as an internal standard (IS).
View Article and Find Full Text PDFFood Res Int
December 2022
College of Material Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou 311121, PR China. Electronic address:
An online sandwich derivatization and stacking strategy using capillary electrophoresis was developed and successfully applied to the preconcentration of multi-amino acids in two functional food samples. Amino acids were derived with 4-Chloro-7-nitro-1, 2, 3-benzoxadiazole (NBD-Cl) to make the new compounds with chromophore in the stacking process, then the derivatives were stacked by on-column sample preconcentration and detected at 475 nm UV wavelength. The novel sandwich injection sequence was amino acids, NBD-Cl, and amino acids separately.
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