the present study describes the fragmentation under electron ionization (ei) of gas phase serine and threonine amino acids. ab initio methods were performed to calculate the fragmentation paths and interpret the mass spectra. the six lowest energy conformers of l-serine, l-threonine and l-allo-threonine were obtained with b3lyp, g3mp2 and mp2 methods. the adiabatic and vertical ionization energ...

proteins are fundamental components of cells which mediate many essential biological processes. proteomics is a rapidly growing field for the study of proteome, the protein complement expressed by the genome of an organism or cell type. the large-scale analysis of proteins leads to a more comprehensive view of molecular and cellular pathways that improves the overall understanding of the comple...

proteomics concerns itself with the characterization and function of all cellular proteins, the ultimate determinants of cellular function. mass spectrometry has emerged as the preferred method for in-depth characterization of the protein components of biological systems. using mass spectrometry, key insights into the composition, regulation and function of molecular complexes and pathways have...

the effects of different factors on growth and bio-oxidation efficiency of a native strain of acidithiobacillus ferrooxidans have been evaluated by the utilization of response surface methodology, rsm. medium ph and iron concentration were found to be the most significant factors while temperature and ammonia concentrations had the least weight within the ranges investigated. optimum operationa...

background pycnocycla spinosa decne. ex boiss is an aromatic plant which showed relaxant effects on isolated ileum contractions and antidiarrheal activity. thirty four components have been extracted from p. spinosa essential oil, of which several major constituents were found to show seasonal variation. objectives the aim of this work is to evaluate the diurnal variation of its oil constituents...

in previous studies, mebudipine, a dihydropyridine calcium channel blocker, showed a considerable potential to be used in cardiovascular diseases. the aim of the current study was to develop a valid method using reversed-phase high performance liquid chromatography coupled with electrospray ionization mass spectrometry to assay mebudipine in the human plasma. separation was achieved on a zorbax...

background many members of the genus satureja have aromatic and medicinal characteristics. objectives results thymol (34.5%), γ-terpinene (18.2%) and ρ-cymene (10.5%) were the main components of the essential oil. the toxicological study on 5637 and kyse cell lines showed ic50 values of 156 μg/ml. the essential oil exhibited considerable antimicrobial activity on tested bacteria and fungi. mate...

proteomics has emerged since 1995 for studying the total proteome of cells, tissues, or organisms at any condition. the study of proteins has a fundamental importance because they are the functional and final molecules of the gene expression process and proteomics could be a valuable technique for achieving this purpose. mass spectrometry is a complementary technique for proteomics that allows ...

a clinical presentation of a metabolic disorder, often first seen in infants who present with poor feeding, vomiting, tachypnea, acidosis, hyperammonemia, ketosis, ketonuria, irritability, and convulsions or hypotonia and lethargy, findings that are otherwise suggestive of neonatal sepsis diseases with oa isovaleric and propionic acidemias, maple syrup urine disease, medium chain acyl dehydroge...