Publications by authors named "Tsuyoshi Mizutani"

Interleukin-1 receptor-associated kinase 4 (IRAK4) is a critical molecule in Toll-like receptor/interleukin-1 receptor signaling and an attractive therapeutic target for a wide range of inflammatory and autoimmune diseases as well as cancers. In our search for novel IRAK4 inhibitors, we conducted structural modification of a thiazolecarboxamide derivative 1, a lead compound derived from high-throughput screening hits, to elucidate structure-activity relationship and improve drug metabolism and pharmacokinetic (DMPK) properties. First, conversion of the thiazole ring of 1 to an oxazole ring along with introduction of a methyl group at the 2-position of the pyridine ring aimed at reducing cytochrome P450 (CYP) inhibition were conducted to afford 16.

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Treatment of allenic bromoalkenes bearing a nucleophilic moiety with a catalytic amount of palladium(0) in the presence of TBAF or Cs(2)CO(3) in MeCN affords bicyclic heterocycles in good to high yields, through zipper-mode cascade cyclisation.

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Thermal [2 + 2] cycloaddition of allenes with an additional multiple bond is described. By simply heating the allenenes or allenynes having a three-atom tether in an appropriate solvent such as dioxane or DMF, the distal double bond of the allenic moiety regioselectively participates in the cycloaddition to form bicyclo[4.2.

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Palladium(0)-catalyzed tandem cyclization of allenenes is described. Treatment of allenenes with an aryl halide, potassium carbonate, and catalytic [Pd(PPh(3))(4)] in dioxane afforded tri- or tetracyclic heterocycles in moderate to good yields through insertion of arylpalladium(II) halide into the allenic moiety, intramolecular carbopalladation, and aromatic C--H bond activation. The substituent on the olefin terminus has proven to be essential for the success of the tandem cyclization.

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Matrix metalloproteinase (MMP) has been implicated in joint destruction of chronic arthritis diseases, such as rheumatoid arthritis. FR217840 (2R)-1-([5-(4-fluorophenyl)-2-thienyl]sulfonyl)-N-hydroxy-4-(methylsulfonyl)-2-piperazinecarboxamide is a potent, orally active synthetic MMP inhibitor that inhibits human collagenases (MMP-1, MMP-8 and MMP-13), gelatinases (MMP-2 and MMP-9) and membrane type MMP (MT-MMP) (MT1-MMP/MMP-14). FR217840 also inhibits rat collagenase and gelatinase.

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FR255031 (2-[(7S)-7-[5-(4-ethylphenyl)-2-thienyl]-1,1-dioxido-4-(2-pyridinylcarbonyl)hexahydro-1,4-thiazepin-7-yl]-N-hydroxyacetamide) is a novel synthetic matrix metalloproteinase (MMP) inhibitor that inhibits human collagenases (MMP-1, MMP-8 and MMP-13), gelatinases (MMP-2 and MMP-9) and membrane type 1 MMP (MT1-MMP/MMP-14). FR255031 also inhibits rat collagenase and gelatinase. We studied the effect of FR255031 and Trocade, an inhibitor of collagenase and MMP-14, on a rat collagen-induced arthritis (CIA) model.

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In the course of our studies on non-peptide bradykinin (BK) B(2) receptor ligands, it was suggested that the 4-substituent of the quinoline ring may play a critical role in determining binding affinities for human and guinea pig B(2) receptors, as well as agonist/antagonist properties. We carried out an extensive investigation to elucidate the structure-activity relationships (SAR) for this key pharmacophore. Introduction of lower alkoxy groups to the 4-position of the quinoline ring of 3 led to the identification of 4-ethoxy derivative 22b as a unique partial agonist.

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Introduction of various aliphatic amino groups at the 4-position of the quinoline moiety of our nonpeptide bradykinin (BK) B(2) receptor antagonists afforded highly potent ligands for human B(2) receptor with various affinities for guinea pig B(2) receptor, indicating remarkable species difference. A representative 4-dimethyamino derivative 40a exhibited subnanomolar and nanomolar binding affinities for human and guinea pig B(2) receptors, respectively, and significantly inhibited BK-induced bronchoconstriction in guinea pigs at 10 microg/kg by intravenous administration. Further chemical modification led us to discover unique partial agonists for the human B(2) receptor that increase inositol phosphates (IPs) production by themselves in Chinese hamster ovary (CHO) cells expressing the cloned human B(2) receptor.

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Introduction of nitrogen-containing heteroaromatic groups at the 4-position of the quinoline moiety of our non-peptide B(2) receptor antagonists resulted in enhancing binding affinities for the human B(2) receptor and reducing binding affinities for the guinea pig one, providing new structural insights into species difference. A CoMFA study focused on the diversity of the quinoline moiety afforded correlative and predictive QSAR models of binding for the human B(2) receptor but not for the guinea pig one. A series of 4-(1-imidazolyl)quinoline derivatives could be dissolved in a 5% aqueous solution of citric acid up to a concentration of 10 mg/mL.

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