Our series of competitive antagonists against the G-protein coupled receptor P2Y(14) were found to be highly shifted in the presence of serum (>99% protein bound). A binding assay using 2% human serum albumin (HSA) was developed to guide further SAR studies and led to the identification of the zwitterion 2, which is substantially less shifted (18-fold) than our previous lead compound 1 (323-fold). However, as the bioavailability of 2 was low, a library of ester pro-drugs was prepared (7a-7j) and assessed in vitro.
View Article and Find Full Text PDFA weak, UDP-competitive antagonist of the pyrimidinergic receptor P2RY(14) with a naphthoic acid core was identified through high-throughput screening. Optimization provided compounds with improved potency but poor pharmacokinetics. Acylglucuronidation was determined to be the major route of metabolism.
View Article and Find Full Text PDFBackground: Remodeling of lung tissues during the process of granuloma formation requires significant restructuring of the extra-cellular matrix and cathepsins K, L and S are among the strongest extra-cellular matrix degrading enzymes. Cathepsin K is highly expressed in various pathological granulomatous infiltrates and all three enzymes in their active form are detected in bronchoalveolar lavage fluids from patients with sarcoidosis. Granulomatous inflammation is driven by T-cell response and cathepsins S and L are actively involved in the regulation of antigen presentation and T-cell selection.
View Article and Find Full Text PDFThe trifluoroethylamine group found in cathepsin K inhibitors like odanacatib can be replaced by a difluoroethylamine group. This change increased the basicity of the nitrogen which positively impacted the log D. This translated into an improved oral bioavailability in pre-clinical species.
View Article and Find Full Text PDFUsing the cell-permeable, radioiodinated, irreversible inhibitor BIL-DMK, we probed active cysteine cathepsins in blood. Incubation of the probe in human whole blood followed by separation of white blood cells by dextran sedimentation led to the labeling of one major band at 24kDa. Two-dimensional gel electrophoresis showed that the band resolved in a single protein spot and corresponded to cathepsin S based on its molecular mass, isoelectric point, and Western blot analysis using anti-human cathepsin S antibodies.
View Article and Find Full Text PDFRenin is the first enzyme in the renin-angiotensin-aldosterone system which is the principal regulator of blood pressure and hydroelectrolyte balance. Previous studies suggest that cathepsin B is the activator of the prorenin zymogen. Here, we show no difference in plasma renin activity, or mean arterial blood pressure between wild-type and cathepsin B knockout mice.
View Article and Find Full Text PDFCathepsin S (Cat S) is predominantly expressed in antigen-presenting cells and is up-regulated in several preclinical models of antigen-induced inflammation, suggesting a role in the allergic response. Prophylactic dosing of an irreversible Cat S inhibitor has been shown to attenuate pulmonary eosinophilia in mice, supporting the hypothesis that Cat S inhibition before the initiation of airway inflammation is beneficial in airway disease. In addition, Cat S has been shown to play a role in more distal events in the allergic response.
View Article and Find Full Text PDFTwo cathepsin K inhibitors (CatKIs) were compared with alendronate (ALN) for their effects on bone resorption and formation in ovariectomized (OVX) rabbits. The OVX model was validated by demonstrating significant loss (9.8% to 12.
View Article and Find Full Text PDFRecent studies provided evidence for a significant role of cathepsin S during extracellular remodeling in atherosclerosis. In this study, we investigated the effect of a specific cathepsin S inhibitor on atherosclerotic plaque progression in the brachiocephalic artery. Male and female Apoe-/- mice on a cholate-containing high-fat diet containing or lacking a specific cathepsin S inhibitor were evaluated for the remodeling of atherosclerotic lesions.
View Article and Find Full Text PDFMK-0674 is a potent and selective cathepsin K inhibitor from the same structural class as odanacatib with a comparable inhibitory potency profile against Cat K. It is orally bioavailable and exhibits long half-life in pre-clinical species. In vivo studies using deuterated MK-0674 show stereoselective epimerization of the alcohol stereocenter via an oxidation/reduction cycle.
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
March 2008
Identification, characterization and structure elucidation of human metabolites of drug candidates is crucial for the pharmaceutical industry to assess their activity against the therapeutic target of interest and potential toxicological effects. It often requires in vitro synthesis of microgram quantities of metabolites of interest with enzymatic preparations, pre-concentration of the reaction mixture by solid phase extraction (SPE), metabolite isolation using HPLC systems coupled to fraction collectors prior to nuclear magnetic resonance characterization. The method reported herein is a rapid and simple technique using solely off-line mixed phase anionic exchange lipophilic SPE cartridges to selectively isolate glucuronide and sulfate metabolites from their parent compound.
View Article and Find Full Text PDFBioorg Med Chem Lett
February 2008
Odanacatib is a potent, selective, and neutral cathepsin K inhibitor which was developed to address the metabolic liabilities of the Cat K inhibitor L-873724. Substituting P1 and modifying the P2 side chain led to a metabolically robust inhibitor with a long half-life in preclinical species. Odanacatib was more selective in whole cell assays than the published Cat K inhibitors balicatib and relacatib.
View Article and Find Full Text PDFHighly potent, selective, and bioavailable inhibitors of human, mouse, or rat cathepsin S are described. The key structural features combine a sulfonyl moiety attached to a large group in P2 and a small substituent in P3.
View Article and Find Full Text PDFBased on our previous study with trifluoroethylamine as a P2-P3 amide isostere of cathepsin K inhibitor, further optimization led to identification of compound 22 (L-873724) as a potent and selective non-basic cathepsin K inhibitor. This compound showed excellent pharmacokinetics and efficacy in an ovariectomized (OVX) rhesus monkey model. The volumes of distribution close to unity were consistent with this compound not being lysosomotropic, which is a characteristic of basic cathepsin K inhibitors.
View Article and Find Full Text PDFA series of benzotriazole phenyldifluoromethylphosphonic acids were found to be potent PTP-1B inhibitors. Molecular modeling on the X-ray crystal structure of the lead structure led to the design of potent PTP-1B inhibitors that show moderate selectivity against TC-PTP, a very closely related protein tyrosine phosphatase.
View Article and Find Full Text PDFProtein tyrosine phosphatase-1B (PTP-1B) is a negative regulator of insulin signaling. It is thought to carry out this role by interacting with and dephosphorylating the activated insulin receptor (IR). However, little is known regarding the nature of the cellular interaction between these proteins, especially because the IR is localized to the plasma membrane and PTP-1B to the endoplasmic reticulum.
View Article and Find Full Text PDFProtein tyrosine phosphatase 1B (PTP1B) has been implicated in the regulation of the insulin signaling pathway and represents an attractive target for the design of inhibitors in the treatment of type 2 diabetes and obesity. Inspection of the structure of PTP1B indicates that potent PTP1B inhibitors may be obtained by targeting a secondary aryl phosphate-binding site as well as the catalytic site. We report here the crystal structures of PTP1B in complex with first and second generation aryldifluoromethyl-phosphonic acid inhibitors.
View Article and Find Full Text PDFPyridazinone was found to be an excellent core template for selective COX-2 inhibitors. Two potent, selective and orally active COX-2 inhibitors, which were highly efficacious in rat paw edema and rat pyresis models, have been obtained.
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