Glutathione (GSH) is one of the most important antioxidants that plays an essential role in detoxification of reactive oxygen species (ROS) which oxidizes to glutathione disulfide (GSSG). Paraquat (PQ), awidely used herbicide, causes pulmonary injury with the productionof ROS. Excessive ROS accumulation as a consequence of PQ exposure are frequently targeted by GSH thereby oxidative stress lead...

Gas chromatography-mass spectrometry (GC-MS) is a widely used analytical technique in metabolomics. GC provides the highest resolution of any standard chromatographic separation method, and with modern instrumentation, retention times are very consistent between analyses. Electron impact ionization and fragmentation is generally reproducible between instruments and extensive libraries of spectr...

Herein, twoN-substituted coumaryl hydroxylamines (compounds 1a and 1b) with long aliphatic chains were prepared in 8 steps with a novel synthetic protocol. They served as derivatization agents for aldehydes by the formation of nitrones under mild conditions, which can be readily analysed by LC-MS with good chromatographic performance, excellent fluorescent response, and high ionization strength...

Matrix-assisted laser desorption/ionization (MALDI) is a new tool that can acquire the localization of various compounds, including peptides and proteins, directly from tissue sections. Despite the important developments recently performed in the field of MALDI imaging in tissue, the precise identification of compounds still needs improvement. We have developed N-terminal chemical derivatizatio...

The high-resolution structure of the DNA (5'-GTGTACA-C-3') with the selenium derivatization at the 2'-position of T2 was determined via MAD and SAD phasing. The selenium-derivatized structure (1.28 A resolution) with the 2'-Se modification in the minor groove is isomorphorous to the native structure (2.0 A). To directly compare with the conventional bromine derivatization, we incorporated bromi...

In the analysis of organotin compounds, derivatization is required in order to achieve more volatile compounds prior to the use of techniques based on GC separation. Derivatization can be considered as one of the main critical steps in organotin analysis, since low yields of derivatization and losses of analytes can easily occur at this stage, and lead to an underestimation of their content in ...

Amino acid analysis (AAA) is one of the best methods to quantify peptides and proteins. Two general approaches to quantitative AAA exist, namely, classical postcolumn derivatization following ion-exchange chromatography and precolumn derivatization followed by reversed-phase HPLC (RP-HPLC). Excellent instrumentation and several specific methodologies are available for both approaches, and both ...

Selenium derivatization (via selenomethionine) of proteins for crystal structure determination via MAD phasing has revolutionized protein X-ray crystallography. It is estimated that over two thirds of all new crystal structures of proteins have been determined via Se-Met derivatization. Similarly, selenium functionalities have also been successfully incorporated into nucleic acids to facilitate...

The thesis describes the development of new and improved methods for analyzing degradation markers from organophosphorus Chemical Warfare Agents (CWAs). Paper I and II describes an innovative and significantly improved method for the enrichment, derivatization (trimethysilylation) and GC-MS analysis of a broad range of organophosphorus CWAs degradation markers, namely the alkylphosphonic acids ...

BacBackground and Objectives: polyamines (putrecsine, spermidine and spermine) are widespread components, which can be found in most of the foods like meat, fruits, vegetables, cheese and wine. Studies show that reducing the level of polyamines in cells may help to slow down some cancer processes however, dietary polyamines may be required in wound healing, and for growth, maturation and regene...