A strong anion-exchanger was used as a trapping column to perform on-line coupling of ion-pair chromatography with electrospray ionisation mass spectrometry. Ion-pairing reagents were used to retain polar analytes of low molecular mass away from the solvent front in reversed-phase LC. The trapping column enabled removal of the non-volatile counter-ions from the mobile phase prior to detection, so that the electrospray process could be performed with favourable ionisation conditions and without contamination of the interface. The efficiency of the trapping process was studied for 1-octanesulfonic acid and sodium dodecyl sulfate as ion-pairing reagents. Using this on-line trapping method, biopterin and guanidine could be retained with a k'>2 and detected by electrospray mass spectrometry with a stable signal.
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http://dx.doi.org/10.1016/s0021-9673(99)00526-9 | DOI Listing |
Sci Rep
January 2025
Stem Cells Technology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
In this study, new cinnamic acid linked to triazole acetamide derivatives was synthesized and evaluated for anti-Alzheimer and anti-melanogenesis activities. The structural elucidation of all analogs was performed using different analytical techniques, including H-NMR, C-NMR, mass spectrometry, and IR spectroscopy. The synthesized compounds were assessed in vitro for their inhibitory activities against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and tyrosinase enzymes.
View Article and Find Full Text PDFActa Pharmacol Sin
January 2025
National and Local United Engineering Lab of Druggability and New Drugs Evaluation, Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Guangdong Province Engineering Laboratory for Druggability and New Drug Evaluation, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China.
Sorting nexins (SNXs) as the key regulators of sorting cargo proteins are involved in diverse diseases. SNXs can form the specific reverse vesicle transport complex (SNXs-retromer) with vacuolar protein sortings (VPSs) to sort and modulate recovery and degradation of cargo proteins. Our previous study has shown that SNX3-retromer promotes both STAT3 activation and nuclear translocation in cardiomyocytes, suggesting that SNX3 might be a critical regulator in the heart.
View Article and Find Full Text PDFAnal Bioanal Chem
January 2025
Institute of Inorganic and Analytical Chemistry, University of Münster, Münster, Germany.
Tattooing is a popular form of body art that has evolved from ancient times into being part of modern society. The understanding of biotransformation processes of coloring tattoo pigments in human skin is limited although skin reactions to tattoos with unknown culprits occur. Electrochemistry coupled to mass spectrometry (EC-MS) has widely been used as a tool for a purely instrumental approach to simulating the enzymatic biotransformation of xenobiotics.
View Article and Find Full Text PDFAnal Bioanal Chem
January 2025
Doping Control Laboratory, Department of Diagnostic Sciences, Ghent University, Block B, Ottergemsesteenweg 460, BE-9000, Ghent, Belgium.
Dried urine spots have recently been proposed as an alternative matrix in the anti-doping field. Drying urine may open the opportunity to limit microbial and thermal degradation of the prohibited substances during transportation to the anti-doping laboratories without the need for refrigeration or freezing. In this study, a multi-targeted initial testing procedure was developed for the determination of 237 prohibited drugs/metabolites from 11 different classes in dried urine spots.
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January 2025
Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, No.1 East Jianshe Road, Erqi District, Zhengzhou, 450052, China.
Increasing evidence points toward an essential role for complement activation in the pathogenesis of diabetic kidney disease (DKD). However, the precise molecular mechanisms remain unclear, and the pathway predominantly contributing to complement activation in DKD is of particular interest. In this study, the glomerular proteome, especially the profiles of the complement proteins, was analyzed in kidney biopsies from 40 DKD patients and 10 normal controls using laser microdissection-assisted liquid chromatography-tandem mass spectrometry (LMD-LC-MS/MS).
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