RESUMEN
NMR spectroscopy is one of the most powerful techniques to simultaneously obtain qualitative and quantitative information in chemical analysis. Despite its versatility, the applications of NMR in the study of biofluids are often limited by the insensitivity of the technique, further aggravated by the poor signal dispersion in the (1)H spectra. Recent advances in para-H2 induced hyperpolarization have proven to address both these limitations for specific classes of compounds. Herein, this approach is for the first time applied for quantitative determination in biofluid extracts. We demonstrate that a combination of solid phase extraction, para-hydrogen induced hyperpolarization and selective NMR detection quickly reveals a doping substance, nikethamide, at sub-µM concentrations in urine. We suggest that this method can be further optimized for the detection of different analytes in various biofluids, anticipating a wider application of hyperpolarized NMR in metabolomics and pharmacokinetics studies in the near future.
Asunto(s)
Espectroscopía de Resonancia Magnética , Niquetamida/orina , Urinálisis/métodos , Humanos , Hidrógeno , MetabolómicaRESUMEN
In an attempt to mimic the biosynthetic efficiencies of nature and in a search for greener, more sustainable alternatives to nowadays ways of producing chemicals, one-pot cascade reactions have attracted a lot of attention in the past decade. Since most catalysts are not compatible with each other, compartmentalization techniques have often been applied to prevent catalyst inactivation. A various array of nanoreactors have been developed to meet the demand of having a site-isolated catalyst system, while maintaining the catalyst activity. Both multienzyme nanoreactors as well as enzyme/metal catalyst or organocatalyst systems have shown great potential in one-pot cascade reactions and hold promise for future developments in this field.
Asunto(s)
Reactores Biológicos , Nanotecnología , Bencenosulfonatos/química , Materiales Biocompatibles/química , Materiales Biocompatibles/metabolismo , Catálisis , Enzimas/metabolismo , Metales/química , Nanopartículas/química , Nanopartículas/metabolismo , Polímeros/química , Pirrolidinas/químicaRESUMEN
We have demonstrated that multiple crude enzyme lysates containing a hydroxynitrile lyase can be used for the enantioselective synthesis of cyanohydrins from aldehydes in microchannels. Using a microreactor setup, two important parameters were efficiently screened consuming only minute amounts of reagents. More importantly, results from the continuous flow reaction were fully consistent with results obtained from larger batchwise processes in which a stable emulsion was formed.
Asunto(s)
Aldehídos/química , Reactores Biológicos , Liasas de Carbono-Carbono/química , Carbono/química , Hevea/enzimología , Técnicas Analíticas Microfluídicas/métodos , Nitrilos/química , Análisis de Inyección de Flujo/métodosRESUMEN
Novel synthetic procedures for the modification of non-proteinogenic acetylene-containing amino acids have been developed. The functionalization either proceeds via zinc/copper-mediated introduction of alkyl substituents, or via tungsten-catalyzed ring-closing alkyne metathesis reactions.