Yasunao Hattori

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Let (X, d) a metric space and BX = X × R denote the partially ordered set of (generalized) formal balls in X. We investigate the topological structures of BX, in particular the relations between the Lawson topology and the product topology. We show that the Lawson topology coincides with the product topology if (X, d) is a totally bounded metric space, and(More)
The design and evaluation of low molecular weight peptide-based severe acute respiratory syndrome (SARS) chymotrypsin-like protease (3CL) protease inhibitors are described. A substrate-based peptide aldehyde was selected as a starting compound, and optimum side-chain structures were determined, based on a comparison of inhibitory activities with Michael(More)
In Saccharomyces cerevisiae, genes involved in thiamin pyrophosphate (TPP) synthesis (THI genes) and the pyruvate decarboxylase structural gene PDC5 are transcriptionally induced in response to thiamin starvation. Three positive regulatory factors (Thi2p, Thi3p, and Pdc2p) are involved in the expression of THI genes, whereas only Pdc2p is required for the(More)
Exosomes, the natural vehicles of various biological molecules, have been examined in several research fields including drug delivery. Although understanding of the biological functions of exosomes has increased, how exosomes are transported between cells remains unclear. We hypothesized that cell tropism is important for effective exosomal intercellular(More)
The asymmetric total synthesis of murisolin, (15R, 16R, 19R, 20S)-murisolin A, and (15R, 16R, 19S, 20S)-16,19-cis-murisolin was performed by using an epoxy alcohol as a versatile chiral building block for synthesizing the stereoisomers of mono-THF annonaceous acetogenins. The inhibitory activity of these murisolin compounds was examined with bovine heart(More)
Studies of the action mechanism of acetogenins, the most potent and structurally unique inhibitors of bovine heart mitochondrial complex I (NADH-ubiquinone oxidoreductase), are valuable in characterizing the inhibitor binding site in this enzyme. Our previous study deepened our understanding of the dynamic function of the spacer region of bis-THF(More)
A chromene-type compound, daedalin A (1), was isolated from mycelial culture broth of Daedalea dickinsii. Based on spectroscopic data, the structure of 1 was found to be (2R)-6-hydroxy-2-hydroxymethyl-2-methyl-2H-chromene. Daedalin A (1) strongly inhibited the activity of tyrosinase (IC(50): 194 muM). In addition, 1 also showed 1,1-diphenyl-2-picrylhydrazyl(More)
The design and evaluation of a novel decahydroisoquinolin scaffold as an inhibitor for severe acute respiratory syndrome (SARS) chymotrypsin-like protease (3CL(pro)) are described. Focusing on hydrophobic interactions at the S2 site, the decahydroisoquinolin scaffold was designed by connecting the P2 site cyclohexyl group of the substrate-based inhibitor to(More)
Total synthesis of pyranicin was achieved using Cl2Pd(CH3CN)2-catalyzed diastereoselective cyclization of the allylic ester as the key step. The inhibitory activity of this compound for mitochondrial NADH-ubiquinone oxidoreductase (complex I) was slightly poorer than that of ordinary mono-THF acetogenins such as cis-solamin.
A superior substrate sequence for BACE1 containing transition-state mimics at the scissile site was evaluated as a protease inhibitor. Hydroxymethylcarbonyl (HMC) and hydroxyethylamine (HEA) isosteres were selected as the transition state mimics, and incorporated into the scissile site of the superior sequence covering the P4 to P1' sites(More)