Synthesis and characterization of fluorescent displacers for online monitoring of displacement chromatography

Detection of trace proteins in multicomponent mixtures using displacement chromatography

Model protein feed mixtures containing three abundant and seven trace proteins at various concentrations were identified and employed in a series of displacement experiments. Reversed-phase liquid chromatography (RPLC) and matrix assisted laser desorption ionization-time-of-flight (MALDI-TOF) mass spectrometry were used to evaluate the compositions of both the feed mixtures and effluent fractions from the displacement experiments. The results demonstrated that trace proteins were focused at the boundaries between the abundant solutes where they were enriched and concentrated. For many of the multicomponent feed mixtures, mass spectrometry analyses of the displacement column effluent fractions resulted in the identification of trace proteins that were not detectable in the feed. In addition, the use of minimal or no salt in the carrier solutions enabled the analysis of displacement fractions by direct infusion mass spectrometry. These results are significant in that they indicate that while the presence of abundant proteins can often be problematic for the detection of trace components, displacement chromatography may be able to employ these abundant proteins to focus trace proteins in the displacement train, thus facilitating detection.

Enhancement of the click chemistry for the inverse Diels Alder technology by functionalization of amide-based monomers

In the near future personalized medicine with nucleic acids will play a key role in molecular diagnostics and therapy, which require new properties of the nucleic acids, like stability against enzymatic degradation. Here we demonstrate that the replacement of nucleobases with PNA by functional molecules harbouring either a dienophile or a diene reactivity is feasible and confers all new options for functionalization. These newly developed derivatives allow independent multi-ligations of multi-faceted components by use of the inverse Diels Alder technology. The high chemical stability and the ease of synthesis qualify these polyamide building blocks as favourites for intracellular delivery and targeting applications. This allows local drug concentrations sufficient for imaging and therapy and simultaneously a reduction of the application doses. It is important to point out that this technology is not restricted to ligation of medicament material; it is also a candidate to develop new and highly efficient active compounds for a "sustainable pharmacy".