Measurement of methylglyoxal by stable isotopic dilution analysis LC-MS/MS with corroborative prediction in physiological samples

2014 ◽  
Vol 9 (8) ◽  
pp. 1969-1979 ◽  
Author(s):  
Naila Rabbani ◽  
Paul J Thornalley
Keyword(s):  
Isotopic Dilution ◽  
Stable Isotopic ◽  
Isotopic Dilution Analysis

scholarly journals Reading patterns of proteome damage by glycation, oxidation and nitration: quantitation by stable isotopic dilution analysis LC-MS/MS

2020 ◽  
Vol 64 (1) ◽  
pp. 169-183 ◽  
Author(s):  
Naila Rabbani ◽  
Paul J. Thornalley
Keyword(s):  
Protein Modification ◽  
Early Stage ◽  
Reference Method ◽  
Vascular Complication ◽  
Extracellular Proteins ◽  
Protein Glycation ◽  
Isotopic Dilution ◽  
Diagnostic Potential ◽  
Stable Isotopic ◽  
Isotopic Dilution Analysis

Abstract Liquid chromatography-tandem mass spectrometry (LC-MS/MS) provides a high sensitivity, high specificity multiplexed method for concurrent detection of adducts formed by protein glycation, oxidation and nitration, also called AGEomics. Combined with stable isotopic dilution analysis, it provides for robust quantitation of protein glycation, oxidation and nitration adduct analytes. It is the reference method for such measurements. LC-MS/MS has been used to measure glycated, oxidized and nitrated amino acids – also called glycation, oxidation and nitration free adducts, with a concurrent quantitation of the amino acid metabolome in physiological fluids. Similar adduct residues in proteins may be quantitated with prior exhaustive enzymatic hydrolysis. It has also been applied to quantitation of other post-translation modifications, such as citrullination and formation of Nε-(γ-glutamyl)lysine crosslink by transglutaminases. Application to cellular and extracellular proteins gives estimates of the steady-state levels of protein modification by glycation, oxidation and nitration, and measurement of the accumulation of glycation, oxidation and nitration adducts in cell culture medium and urinary excretion gives an indication of flux of adduct formation. Measurement of glycation, oxidation and nitration free adducts in plasma and urine provides for estimates of renal clearance of free adducts. Diagnostic potential in clinical studies has been enhanced by the combination of estimates of multiple adducts in optimized diagnostic algorithms by machine learning. Recent applications have been in early-stage detection of metabolic, vascular and renal disease, and arthritis, metabolic control and risk of developing vascular complication in diabetes, and a blood test for autism.

Isotopic dilution analysis by solvent extraction—V☆Determination of traces of iron

Talanta ◽  
1963 ◽  
Vol 10 (4) ◽  
pp. 375-381 ◽  
Author(s):  
Jiří Starý ◽  
Jaromír Ru̇žička ◽  
Milan Salamon
Keyword(s):  
Solvent Extraction ◽  
Isotopic Dilution ◽  
Isotopic Dilution Analysis

scholarly journals Increased DNA Dicarbonyl Glycation and Oxidation Markers in Patients with Type 2 Diabetes and Link to Diabetic Nephropathy

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Sahar Waris ◽  
Brigitte M. Winklhofer-Roob ◽  
Johannes M. Roob ◽  
Sebastian Fuchs ◽  
Harald Sourij ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Diabetic Nephropathy ◽  
Dna Oxidation ◽  
Isotopic Dilution ◽  
Multiple Logistic Regression ◽  
Chromatography Tandem Mass Spectrometry ◽  
Stable Isotopic ◽  
Liquid Chromatography Tandem Mass ◽  
Excretion Rates

Aim. The aim of this study was to assess the changes of markers of DNA damage by glycation and oxidation in patients with type 2 diabetes and the association with diabetic nephropathy.Methodology. DNA oxidation and glycation adducts were analysed in plasma and urine by stable isotopic dilution analysis liquid chromatography-tandem mass spectrometry. DNA markers analysed were as follows: the oxidation adduct 7,8-dihydro-8-oxo-2′-deoxyguanosine (8-OxodG) and glycation adducts of glyoxal and methylglyoxal—imidazopurinones GdG, MGdG, and N2-(1,R/S-carboxyethyl)deoxyguanosine (CEdG).Results. Plasma 8-OxodG and GdG were increased 2-fold and 6-fold, respectively, in patients with type 2 diabetes, with respect to healthy volunteers. Median urinary excretion rates of 8-OxodG, GdG, MGdG, and CEdG were increased 28-fold, 10-fold, 2-fold, and 2-fold, respectively, in patients with type 2 diabetes with respect to healthy controls. In patients with type 2 diabetes, nephropathy was associated with increased plasma 8-OxodG and increased urinary GdG and CEdG. In a multiple logistic regression model for diabetic nephropathy, diabetic nephropathy was linked to systolic blood pressure and urinary CEdG.Conclusion. DNA oxidative and glycation damage-derived nucleoside adducts are increased in plasma and urine of patients with type 2 diabetes and further increased in patients with diabetic nephropathy.

Synthesis of 13C-Labeled Steroids

Synthesis ◽  
2019 ◽  
Vol 51 (23) ◽  
pp. 4311-4337
Author(s):  
Fabrice Dénès ◽  
Julien Farard ◽  
Jacques Lebreton
Keyword(s):  
Biological Activities ◽  
Wide Spectrum ◽  
Isotopic Dilution ◽  
Side Chain ◽  
Unsaturated Ketone ◽  
Liquid Chromatography Mass Spectrometry ◽  
Partial Synthesis ◽  
Analytical Technique ◽  
Stable Isotopic ◽  
Partial Degradation

Due to the wide spectrum of biological activities of steroids, the detection and quantification of steroidal residues in various biological materials are crucial for drug development, doping prevention, and environmental protection. In addition, the analytical technique of stable isotopic dilution (SID) by Liquid Chromatography-Mass Spectrometry (LC-MS) requires 13C-labeled steroids as standards to provide accurate and reproducible steroid quantification. In this context, the synthesis of 13C-labeled steroids is reviewed. The approaches based on partial synthesis starting from commercially available steroids have been, by far, the most commonly employed strategy.1 Introduction2 Hemisynthesis of 13C3-Labeled Steroids via Partial Degradation of the A Ring2.1 Degradation of the A Ring to an Enol Lactone2.1.1 Introduction of 13C Atom(s) via Claisen Condensation: Turner’s Strategy2.1.2 Introduction of 13C Atom(s) with 13C-Labeled 5-(Diethylphosphono)pentan-2-one Ethylene Ketal Based on the Fujimoto–Belleau Reaction2.2 Degradation of the A Ring and Introduction of 13C Atom(s) with [13C3]-1-(Triphenylphosphoranylidene)propan-2-one3 Construction of the A Ring from an α,β-Unsaturated Ketone with 13C-Labeled 1-Iodo-3,3-(ethylenedioxy)butane as Electrophile4 Construction of the A and B rings: Stork’s Strategy5 Hemisynthesis with Introduction of 13C Atom(s) in the C17 Side Chain6 Conclusion

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