JAK1, JAK2, JAK3, and TYK2 belong to the JAK (Janus kinase) family. They play critical roles in cytokine signaling. Constitutive activation of JAK/STAT pathways is associated with a wide variety of diseases.
View Article and Find Full Text PDFJanus kinases (JAKs) have been demonstrated to be critical in cytokine signaling and have thus been implicated in both cancer and inflammatory diseases. The JAK family consists of four highly homologous members: JAK1-3 and TYK2. The development of small-molecule inhibitors that are selective for a specific family member would represent highly desirable tools for deconvoluting the intricacies of JAK family biology.
View Article and Find Full Text PDFWe have identified a class of azabenzimidazoles as potent and selective JAK1 inhibitors. Investigations into the SAR are presented along with the structural features required to achieve selectivity for JAK1 versus other JAK family members. An example from the series demonstrated highly selective inhibition of JAK1 versus JAK2 and JAK3, along with inhibition of pSTAT3 in vivo, enabling it to serve as a JAK1 selective tool compound to further probe the biology of JAK1 selective inhibitors.
View Article and Find Full Text PDFStructure based design, synthesis, and biological evaluation of a novel series of 1-methyl-1H-imidazole, as potent Jak2 inhibitors to modulate the Jak/STAT pathway, are described. Using the C-ring fragment from our first clinical candidate AZD1480 (24), optimization of the series led to the discovery of compound 19a, a potent, orally bioavailable Jak2 inhibitor. Compound 19a displayed a high level of cellular activity in hematopoietic cell lines harboring the V617F mutation and in murine BaF3 TEL-Jak2 cells.
View Article and Find Full Text PDFGlucokinase (GK) acts as a glucose sensor by facilitating glucose phosphorylation into glucose-6-phosphate (G6P) in the liver and pancreas, the two key target tissues. LCZ960, a glucokinase activator exerts a stimulatory effect on GK activity in hepatocytes in vitro. This study aimed to verify in vivo that LCZ960 stimulates glucose uptake primarily through a mechanism involving hepatic GK activation.
View Article and Find Full Text PDFThe discovery of the activating mutation V617F in the JH2 domain of Jak2 and the modulation of oncogenic Stat3 by Jak2 inhibitors have spurred a great interest in the inhibition of the Jak2/Stat pathway in oncology. In this Letter, we communicate the discovery of novel inhibitors of the Jak2/Stat5 axis, the N-(1H-pyrazol-3-yl)pyrimidin-2-amino derivatives. The rationale, synthesis and biological evaluation of these derivatives are reported.
View Article and Find Full Text PDFAryl-amines are commonly used synthons in modern drug discovery, however a minority of these chemical templates have the potential to cause toxicity through mutagenicity. The toxicity mostly arises through a series of metabolic steps leading to a reactive electrophilic nitrenium cation intermediate that reacts with DNA nucleotides causing mutation. Highly detailed in silico calculations of the energetics of chemical reactions involved in the metabolic formation of nitrenium cations have been performed.
View Article and Find Full Text PDFSynthesis and biological evaluation of a series of 6-aminopyrazolyl-pyridine-3-carbonitriles as JAK2 kinase inhibitors was reported. Biochemical screening, followed by profile optimization, resulted in JAK2 inhibitors exhibiting good kinase selectivity, pharmacokinetic properties, physical properties and pharmacodynamic effects.
View Article and Find Full Text PDFThe myeloproliferative neoplasms, polycythemia vera, essential thrombocythemia, and idiopathic myelofibrosis are a heterogeneous but related group of hematological malignancies characterized by clonal expansion of one or more myeloid lineages. The discovery of the Jak2 V617F gain of function mutation highlighted Jak2 as a potential therapeutic target in the MPNs. Herein, we disclose the discovery of a series of pyrazol-3-yl pyrimidin-4-amines and the identification of 9e (AZD1480) as a potent Jak2 inhibitor.
View Article and Find Full Text PDFThiazol-2-yl amine was identified as an isosteric replacement for pyrazol-3-yl amine during our efforts to identify potent and selective JAK2 inhibitors. The rationale, synthesis and biological evaluation of several analogs is reported, along with the in vivo evaluation of the lead compounds.
View Article and Find Full Text PDFPersistent activation of Stat3 is oncogenic and is prevalent in a wide variety of human cancers. Chronic cytokine stimulation is associated with Stat3 activation in some tumors, implicating cytokine receptor-associated Jak family kinases. Using Jak2 inhibitors, we demonstrate a central role of Jaks in modulating basal and cytokine-induced Stat3 activation in human solid tumor cell lines.
View Article and Find Full Text PDFTwo classes of compounds, thiocarbamates 1 and triazoles 2, have been identified as HIV RT RNase H inhibitors using a novel FRET-based HTS assay. The potent analogs in each series exhibited selectivity and were active in cell-based assays. In addition, saturable, 1:1 stoichiometric binding to target was established and time of addition studies were consistent with inhibition of RT-mediated HIV replication.
View Article and Find Full Text PDFBioorg Med Chem Lett
December 2009
The design, synthesis and biological evaluation of a series of pyrazol-3-ylamino pyrazines as potent and selective JAK2 kinase inhibitors is reported, along with the pharmacokinetic and pharmacodynamic properties of lead compounds.
View Article and Find Full Text PDFType 2 diabetes is a polygenic disease which afflicts nearly 200 million people worldwide and is expected to increase to near epidemic levels over the next 10-15 years. Glucokinase (GK) activators are currently under investigation by a number of pharmaceutical companies with only a few reaching early clinical evaluation. A GK activator has the promise of potentially affecting both the beta-cells of the pancreas, by improving glucose sensitive insulin secretion, as well as the liver, by reducing uncontrolled glucose output and restoring post-prandial glucose uptake and storage as glycogen.
View Article and Find Full Text PDFThe Janus-associated kinase 2 (JAK2) V617F mutation is believed to play a critical role in the pathogenesis of polycythemia vera, essential thrombocythemia, and idiopathic myelofibrosis. We have characterized a novel small molecule JAK2 inhibitor, AZ960, and used it as a tool to investigate the consequences of JAK2 V617F inhibition in the SET-2 cell line. AZ960 inhibits JAK2 kinase with a K(i) of 0.
View Article and Find Full Text PDFBioorg Med Chem Lett
September 2008
The bisamide class of kinase inhibitors was identified as being active against CSF-1R. The synthesis and SAR of pyridyl and thiazolyl bisamides are reported, along with the pharmacokinetic properties and in vivo activity of selected examples.
View Article and Find Full Text PDFThrough high throughput screening of various libraries, substituted styryl naphthalene 6 was identified as an HCMV protease inhibitor. Optimization of various regions of the lead molecule using parallel synthesis resulted in 1,6-substituted naphthalenes 19d-i. These compounds displayed good potency and were selective over elastase, trypsin, and chymotrypsin.
View Article and Find Full Text PDFHerpesviruses encode a serine protease that is essential for the maturation of infectious virions. This protease has a unique polypeptide backbone fold and contains a novel Ser-His-His catalytic triad. It exists in a monomer-dimer equilibrium in solution, but only the dimer form of the enzyme is catalytically active.
View Article and Find Full Text PDFThe synthesis and biological activity of pyrimidotetrazin-6-ones against HCMV protease is described. The mechanism of action for these inhibitors is the oxidation of several cysteine residues to generate cross-linked enzyme.
View Article and Find Full Text PDFCurr Pharm Des
October 2002
Utilization of fat as a long-term energy storage vehicle is crucial for the maintenance of cellular metabolism and is under intricate and many times redundant control mechanisms. Aberrations in the control of energy metabolism is apparent in diseases such as diabetes and obesity and is evident early on in patients with impaired glucose tolerance. Insulin resistance has been observed at the level of muscle, liver and adipose tissue.
View Article and Find Full Text PDFThis article provides evidence of a new class of compounds, 1,3-diaryl-[1H]-pyrazole-4-acetamides, initially identified from their ability to increase glucose transport in an adipocyte and muscle cell line and ultimately demonstrating dramatic glucose lowering in ob/ob mice, a diabetic animal model. The lead compound, 1, possessed some behavioral-like effects which were removed by structural variation during the course of this investigation. Specifically, 11g (R1 = meta-CF(3), Ar2 = 4'biphenyl, R3 = diethylamide) illustrated the potency of this series with ED(50) values for glucose lowering in ob/ob mice of 3.
View Article and Find Full Text PDFThe overproduction of glucose by the liver in NIDDM patients markedly contributes to their fasting hyperglycemia and is a direct consequence of the increased oxidation of excess free fatty acids (FFA) being released from the adipocyte. 2-(1,1-Dimethylethyl)-2-(4-methylphenyl)[1,3]dioxolane (SAH51-641, 1) has previously been demonstrated to reduce glucose levels in animal models of diabetes by reducing fatty acid oxidation and hence depriving the system of the energy and cofactors necessary for gluconeogenesis. However, attempts at lowering glucose levels in vivo with 1 have been associated with toxicity in other organs such as the testes.
View Article and Find Full Text PDFThe optimization of a series of anilide derivatives of (R)-3,3, 3-trifluoro-2-hydroxy-2-methylpropionic acid as inhibitors of pyruvate dehydrogenase kinase (PDHK) is described that started from N-phenyl-3,3,3-trifluoro-2-hydroxy-2-methylpropanamide 1 (IC(50) = 35 +/- 1.4 microM). It was found that small electron-withdrawing groups on the ortho position of the anilide, i.
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