Keisuke Kato

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Choriogenin (Chg) H and L are estrogen-induced chorion precursors. We measured the induction of ChgH and ChgL mRNA in the livers of male medaka fish treated with Orthoester-2k, a selective ligand for estrogen receptor (ER) α, and 2-(4-hydroxyphenyl)-5-hydroxy-1,3-benzoxazole (HPHB), a selective ligand of ERβ. Although both ChgH and ChgL mRNA were induced by(More)
Direct beta-glucosidation between benzyl alcohol and D-glucose (5) using the immobilized beta-glucosidase from almonds with the synthetic prepolymer ENTP-4000 gave a benzyl beta-D-glucoside (1) in 53% yield. The coupling of the benzyl beta-D-glucopyranoside congener (8) derived from 1 with phenyl 2,3,4-tri-O-acetyl-1-thio-beta-D-xylopyranoside (9), ethyl(More)
Cyclization-carbonylation-cyclization coupling reaction (CCC-coupling reaction) of γ-propynyl-1,3-diketones catalyzed by (box)Pd(II) complexes afforded symmetrical ketones bearing two oxabicyclic groups in moderate to excellent yields.
Palladium(II) catalyzed carbonylation of 1-ethynyl-1-propargyl acetate is described; in the absence of the bisoxazoline (box) ligand, the second triple bond did not react, affording cyclic orthoesters and . The use of meso-Phbox-Pd(ii) strikingly changed the course of the reaction, yielding bicyclic lactone by tandem carbonylative cyclization as a result of(More)
Boxing clever: Direct conversion of a terminal alkyne group into a beta-methoxyacrylate is realized with the aid of the bis(oxazoline) ligand (box). Acetyl and ketal protecting groups, free hydroxy groups, and acid-sensitive glycosidic bonds are not affected under the reaction conditions. The one-pot synthesis of (+/-)-dihydrokawain from the homopropargyl(More)
A cyclization-carbonylation-cyclization coupling reaction (CCC-coupling reaction) of (o-alkynylphenyl) (methoxymethyl) sulfides, catalyzed by (box)Pd(II) complexes, afforded symmetrical ketones bearing two benzo[b]thiophene groups in good to excellent yields. This method is applicable to a broad range of substrates.
A novel fluorescent chelating ligand, 2,4-[bis-(2-hydroxy-3-methoxybenzylidene)]-dihydrazinoquinazoline (HBQZ), was synthesized, and the fluorescence characteristics of its complex with metal ions were investigated. Among the 36 different metal ions tested in this study, it was found that HBQZ emits intense fluorescence at 506 nm with an excitation(More)
Effect of pathological prolongation of action potential duration on the α-adrenoceptor-mediated negative inotropy was studied in streptozotocin-induced diabetic mice myocardium. In streptozotocin-treated mouse ventricular myocardium, which had longer duration of action potential than that in control mice, the negative inotropic response induced by(More)
The first total synthesis of (+)-gregatin E and a new total synthesis of (+)-gregatin B are described. Key features of our synthetic approach involve a palladium-catalyzed cyclization-methoxycarbonylation of optically active propargylic acetate and a Suzuki-Miyaura coupling or CuTC-mediated coupling reaction. The absolute configuration of (+)-gregatin E(More)