A rapid HPLC-MS/MS method for the simultaneous quantification of cyclosporine A, tacrolimus, sirolimus and everolimus in human blood samples.

In the past few years, high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) has matured to a true alternative to antibody-based immunoassays in routine therapeutic drug monitoring. In transplantation medicine, mass spectrometry-based assessment of immunosuppressant drug levels is considered a gold standard diagnostic procedure. We describe a fast state-of-the-art routine online solid-phase extraction (SPE) HPLC-MS/MS analysis platform that allows monitoring of cyclosporine A, tacrolimus, sirolimus and everolimus from 50-microl aliquots of EDTA whole blood specimens within 3.

SAR, species specificity, and cellular activity of cyclopentene dicarboxylic acid amides as DHODH inhibitors.

Novel DHODH inhibitors were developed based on a previously described series by introduction of heteroatoms into the cyclopentene ring and hydroxyl groups attached to it. Also, the hydrophobic biphenyl side chain was replaced with benzyloxy phenyl groups. Activities on human, rat, and mouse enzymes indicate a species specificity of these inhibitors.