Rifampin (RIF) is a typical cytochrome P450 (CYP) 3A inducer and inhibitor of organic anion transporting polypeptide (OATP) 1B1 to assess drug-drug interaction (DDI) via CYP3A or OATP1B1 in clinical settings. To ensure sufficient exposure of RIF in DDI studies, it is important to determine plasma RIF concentrations. In this study, we developed a simple RIF assay in a small volume of human plasma by ultraperformance liquid chromatography with tandem mass spectrometry.
View Article and Find Full Text PDFNewly synthesized dehydroxymethyl epoxyquinomycin (DHMEQ) derivatives 6-9, which contain a tertiary hydroxyl group instead of the original secondary hydroxyl group, showed improved solubility in alcohol while maintaining their inhibitory activity against nitric oxide (NO) production, which is used as an indicator of nuclear factor-kappa B (NF-κB) inhibitory activity. We also synthesized a derivative 5 having a cyclopropane ring and a tertiary hydroxyl group and examined its inhibitory activity against NO production. Although it reacted with a nucleophile in a flask, it did not inhibit NO production.
View Article and Find Full Text PDFE7090, a novel fibroblast growth factor receptors inhibitor, is currently under clinical development for the treatment of patients with solid tumors. Assays for the determination of E7090 concentrations in human plasma and urine have been developed using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) to evaluate pharmacokinetic profiles of E7090. E7090 and a deuterated labeled internal standard (IS) were extracted from 50 μL of plasma by protein precipitation.
View Article and Find Full Text PDFLipopolysaccharide (LPS) is a component of the outer membrane of Gram-negative bacteria and causes inflammatory diseases. We searched MeOH extracts of collected marine organisms for inhibitors of LPS-induced nitric oxide (NO) production in RAW264.7 cells and identified prostaglandin A (PGA) as an active compound from the MeOH extract of the soft coral sp.
View Article and Find Full Text PDFLipopolysaccharides (LPS) are associated with various inflammatory diseases; therefore, the inhibition of LPS-induced nitric oxide (NO) production may have extensive therapeutic applications. We searched for inhibitors of NO production in the LPS-stimulated murine macrophage-like cell line RAW264.7 from MeOH extracts of marine organisms.
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