Marek Doskocz

NMR Techniques in Metabolomic Studies: A Quick Overview on Examples of Utilization

Metabolomics is a rapidly developing branch of science that concentrates on identifying biologically active molecules with potential biomarker properties. To define the best biomarkers for diseases, metabolomics uses both models (in vitro, animals) and human, as well as, various techniques such as mass spectroscopy, gas chromatography, liquid chromatography, infrared and UV–VIS spectroscopy and nuclear magnetic resonance. The last one takes advantage of the magnetic properties of certain nuclei, such as 1H, 13C, 31P, 19F, especially their ability to absorb and emit energy, what is crucial for analyzing samples. Among many spectroscopic NMR techniques not only one-dimensional (1D) techniques are known, but for many years two-dimensional (2D, for example, COSY, DOSY, JRES, HETCORE, HMQS), three-dimensional (3D, DART-MS, HRMAS, HSQC, HMBC) and solid-state NMR have been used. In this paper, authors taking apart fundamental division of nuclear magnetic resonance techniques intend to shown their wide application in metabolomic studies, especially in identifying biomarkers.

The decomposition of α-aminophosphine oxides to phosphonic acid derivatives (PIII)

AbstractAminophosphine oxides and aminophosphonates are, in general, very stable compounds. However, following phosphorus–carbon bond cleavage in aqueous acidic media these compounds sometimes decompose to phosphonic acids derivatives (PIII). Despite some controversy in the literature, careful analysis supported by theoretical studies leads to the conclusion that decomposition to PIII derivatives proceeds via an elimination reaction. FigureThe decomposition of α-aminophosphine oxides to phosphonic acid derivatives (PIII)

Weak Hydrogen Bond in Cl3CH· · ·O═P(n-Bu)3

The phosphoryl group (P═O) is able to form hydrogen bonds with the relatively low acidic atoms like in C═H· · · · O═P system. In this article, we present experimental and theoretical investigations on the C═H· · · · O═P hydrogen bond for the complex of tributylphosphine oxide and chloroform.

Theoretical study of spin-spin coupling across the hydrogen (O-H⋯N) bond in adenosine derivatives

AbstractThe study of spin-spin coupling constants across hydrogen bond provides useful information about configuration of complexes. The interesting case of such interactions was observed as a coupling across an intramolecular hydrogen bond in 8-bromo-2′,3′-O-isopropylideneadenosine between the -CH2OH (at 5″ proton) group and the nitrogen atom of adenine. In this paper we report theoretical investigations on the 4hJNH coupling across the H″-C-O-H···N hydrogen bond in adenosine derivatives in various solvent models. FigureCoupling constants in 8-bromo-2′,3′-O-isopropylideneadenosine