Simultaneous Quantification of Metabolites Involved in Central Carbon and Energy Metabolism Using Reversed-Phase Liquid Chromatography−Mass Spectrometry and in Vitro <sup>13</sup>C Labeling
作者:Wen-Chu Yang、Miroslav Sedlak、Fred E. Regnier、Nathan Mosier、Nancy Ho、Jiri Adamec
DOI:10.1021/ac801693c
日期:2008.12.15
Comprehensive analysis of intracellular metabolites is a critical component of elucidating cellular processes. Although the resolution and flexibility of reversed-phase liquid chromatography−mass spectrometry (RPLC−MS) makes it one of the most powerful analytical tools for metabolite analysis, the structural diversity of even the simplest metabolome provides a formidable analytical challenge. Here we describe a robust RPLC−MS method for identification and quantification of a diverse group of metabolites ranging from sugars, phosphosugars, and carboxylic acids to phosphocarboxylics acids, nucleotides, and coenzymes. This method is based on in vitro derivatization with a 13C-labeled tag that allows internal standard based quantification and enables separation of structural isomer pairs like glucose 6-phosphate and fructose 6-phosphate in a single chromatographic run. Calibration curves for individual metabolites showed linearity ranging over more than 2 orders of magnitude with correlation coefficients of R2 > 0.9975. The detection limits at a signal-to-noise ratio of 3 were below 1.0 μM (20 pmol) for most compounds. Thirty common metabolites involved in glycolysis, the pentose phosphate pathway, and tricarboxylic acid cycle were identified and quantified from yeast lysate with a relative standard deviation of less than 10%.
Synthesis of the NK3 receptor antagonist AZD2624 in C-14-, H-3- and C-13-labeled forms
作者:Charles S. Elmore、Peter N. Dorff、Mark E. Powell、James E. Hall、Thomas R. Simpson
DOI:10.1002/jlcr.1858
日期:2011.5.15
treatment for schizophrenia, three labeled forms of the NK3receptorantagonistAZD2624 have been prepared. [3H2]AZD2624 was synthesized by tritiodehalogenation for use in receptor occupancy and autoradiographic studies. [13C6]AZD2624 was prepared for use as an internal standard through the intermediacy of [13C6]isatin, and two C-14 isotopomers of AZD2624 were prepared from [14C]benzoic acid and [14C]isatin