J Am Soc Mass Spectrom
Universités Aix-Marseille I, II & III-CNRS, UMR 6264: Laboratoire Chimie Provence, Spectrométries Appliquées à la Chimie Structurale, Campus Saint-Jérôme, Case 511, 13397, Marseille Cedex 20, France.
Published: July 2011
Isomeric distinction of di- and tri-saccharides could be efficiently achieved by using data previously obtained while performing experiments aimed at discriminating monosaccharides using trimeric ion dissociation with data analysis by the kinetic method. This study shows that effects observed for lower homologues when one of the partners is changed in the metal/reference system (typically a transition metal divalent cation associated to amino acids) can be extrapolated to upper homologues, at least for the tested analyte series. Systems allowing galactose, glucose, and fructose distinction were used as starting conditions to resolve cellobiose, lactose, maltose, and saccharose disaccharides. When a unique dissociation reaction was observed from the trimeric clusters, a new reference was selected based on its propensity to favor the analyte or the reference release, as revealed from monosaccharide experiments, depending on the desired effect. The same approach could be implemented from data obtained for disaccharides to select efficient metal/reference systems to distinguish cellotriose, isomaltotriose, maltotriose, and panose trisaccharides. As a result, method optimization is greatly improved due to an enhanced rationalization of the search for discriminant systems. While 40 systems had to be tested for monosaccharides, by screening five transition metals and eight amino acids, the proposed approach allowed efficient metal/reference systems to be found for disaccharides after testing 18 combinations; then, only four systems had to be scrutinized to achieve trisaccharide distinction. Accurate quantitative analyses could be performed in binary mixtures using three-point calibration curves to correct for competition effects between analytes for the formation of the trimeric clusters.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1007/s13361-011-0128-6 | DOI Listing |
Chemphyschem
January 2025
Keio University Faculty of Science and Technology Graduate School of Science and Technology: Keio Gijuku Daigaku Rikogakubu Daigakuin Rikogaku Kenkyuka, Applied Physics and Physico-Informatics, 3-14-1 Hiyoshi, Kohoku-ku, 223-8522, Yokohama, JAPAN.
Understanding the reversible transformation between two isomeric states of organic molecules under external stimulation is essential for advancing single-molecule device development. Photochromic diarylethene (DAE) derivatives are promising candidates for single molecular switching elements. This study investigates the single-molecule reactions of the closed-form isomer of a DAE derivative on Cu(111) using scanning tunneling microscopy (STM).
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
School of Environment and Safety Engineering, North University of China, Taiyuan, 030051, China.
The initial decomposition reactions of 1,3,5-trinitrobenzene (TNB), picric acid (PA), 2,4,6-trinitrotoluene (TNT), 2,4,6-trinitroaniline (TNA) and 2,4,6-trinitrophenylmethylnitramine (Tetryl) were studied using ReaxFF-lg molecular dynamics simulations, and the substituent effect on the thermal decomposition behaviours of nitrobenzene compounds was evaluated through the reactant number, initial decomposition pathway, products and cluster analysis. The results show that the introduction of substituents could promote the decomposition of the reactants, increase the frequency of the nitro-nitrito isomerization reaction and intermolecular H or O atom transfer reaction, and reduce the frequency of the direct nitro dissociation reaction. Notably, these effects were most obvious in the case of TNT.
View Article and Find Full Text PDFWe report the first implementation of ion mobility mass spectrometry combined with an ultra-high throughput sample introduction technology for high throughput screening (HTS). The system integrates differential ion mobility (DMS) with acoustic ejection mass spectrometry (AEMS), termed DAEMS, enabling the simultaneous quantitation of structural isomers that are the sub-strates and products of isomerase mediated reactions in intermediary metabolism. We demonstrate this potential by comparing DAEMS to a luminescence assay for the isoform of phosphoglycerate mutase (iPGM) distinctively present in pathogens offering an opportunity as a drug target for a variety of microbial and parasite borne diseases.
View Article and Find Full Text PDFFoods
December 2024
Methods and Application of Food Composition Laboratory, Beltsville Human Nutrition Research Center, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, MD 20705, USA.
In the present study, we analyzed the bioactive curcuminoids content in eight capsules (DS-1-DS-7 and DS-9), one tablet (DS-8), three ground turmeric samples (DS-10-DS-12), and three ground turmeric rhizomes (TR-1, TR-2, and TR-3). Initial screening with infrared and ultraviolet-visible spectroscopy coupled with a principal component analysis (PCA) revealed distinct differences between the samples analyzed. Hence, targeted and untargeted analyses were performed using ultra-high-performance liquid chromatography and gas chromatography coupled with mass spectrometry detections.
View Article and Find Full Text PDFNature
January 2025
Department of Chemistry, The University of Hong Kong, Hong Kong SAR, China.
Mimicking the superstructures and properties of spherical biological encapsulants such as viral capsids and ferritin offers viable pathways to understand their chiral assemblies and functional roles in living systems. However, stereospecific assembly of artificial polyhedra with mechanical properties and guest-binding attributes akin to biological encapsulants remains a formidable challenge. Here we report the stereospecific assembly of dynamic supramolecular snub cubes from 12 helical macrocycles, which are held together by 144 weak C-H hydrogen bonds.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!
© LitMetric 2025. All rights reserved.