A5023940411- Chemical Synthesis and Analysis
- DNA and Nucleic Acid Chemistry
- Porphyrin and Phthalocyanine Chemistry
- Polyamine Metabolism and Applications
- Click Chemistry and Applications
- Metal-Catalyzed Oxygenation Mechanisms
- RNA Interference and Gene Delivery
- Advanced biosensing and bioanalysis techniques
- Bacteriophages and microbial interactions
- Supramolecular Self-Assembly in Materials
- Luminescence and Fluorescent Materials
- Epigenetics and DNA Methylation
- Molecular Sensors and Ion Detection
- Advanced Biosensing Techniques and Applications
- RNA and protein synthesis mechanisms
- Metal complexes synthesis and properties
- Amino Acid Enzymes and Metabolism
- Porphyrin Metabolism and Disorders
- Biopolymer Synthesis and Applications
- Carbohydrate Chemistry and Synthesis
- Photochromic and Fluorescence Chemistry
- Eicosanoids and Hypertension Pharmacology
- Analytical Chemistry and Sensors
- Cancer-related gene regulation
- Antimicrobial Peptides and Activities
Nagoya City University
2015-2024
Kyoto Institute of Technology
2022-2023
Ritsumeikan University
2013
The University of Tokyo
1997-2009
University of Wisconsin–Madison
2001-2006
Georgetown University
2005-2006
Georgetown University Medical Center
2005-2006
University of Michigan
2005-2006
Walter and Eliza Hall Institute of Medical Research
2006
Osaka University
2004
To characterize fullerenes (C60 and C70) as photosensitizers in biological systems, the generation of active oxygen species, through energy transfer (singlet 1O2) electron (reduced radicals such superoxide anion radical O2-• hydroxyl •OH), was studied by a combination methods, including biochemical (DNA-cleavage assay presence various scavengers species), physicochemical (EPR trapping near-infrared spectrometry), chemical methods (nitro blue tetrazolium (NBT) method). Whereas 1O2 generated...
Fluorescein is one of the best available fluorophores for biological applications, but factors that control its fluorescence properties are not fully established. Thus, we initiated a study aimed at providing strategy rational design functional probes bearing fluorescein structure. We have synthesized various kinds derivatives and examined relationship between their highest occupied molecular orbital (HOMO) levels benzoic acid moieties obtained by semiempirical PM3 calculations. It was...
Short cationic peptides derived from DNA-binding proteins, of which HIV Tat is a prototype, can cross the membranes living cells, and they bring covalently attached moieties (proteins, drugs) along with them. We show that β-amino acid analogue 47-57 enters HeLa cells comparable efficiency to itself (YGRKKRRQRRR). The β-peptide comprised residues bear appropriate side chain at β-carbon. Both α- were conjugated fluorescein N terminus, cell penetration was monitored by confocal fluorescence...
Lysine-specific demethylase 1 (LSD1/KDM1) demethylates histone H3, in addition to tumor suppressor p53 and DNA methyltransferase (Dnmt1), thus regulating eukaryotic gene expression by altering chromatin structure. Specific inhibitors of LSD1 are desired as anticancer agents, because aberrations associated with several cancers, inhibition restores the abnormally silenced genes cancerous cells. In this study, we designed synthesized candidate compounds inhibit LSD1, based on structures...
The development of molecules that bind to specific protein surface sites and inhibit protein−protein interactions is a fundamental challenge in molecular recognition. New strategies for approaching this could have important long-term ramifications biology medicine. We are exploring the concept unnatural oligomers with well-defined conformations ("foldamers") can mimic secondary structural elements thereby block interactions. Here, we describe identification analysis helical peptide-based...
The first fluorescent chemical traps for (1)O(2) have been developed. DPAXs react specifically with to yield the corresponding endoperoxides, DPAX-EPs (see scheme; X = H, Cl, F). scarcely fluoresce, while are strongly fluorescent. Since fluorescence of these probes is unaffected by H(2)O(2), superoxide, and nitric oxide, they useful selective detection in biological systems.
Molecules that bind to specific surface sites on proteins are of great interest from both fundamental and practical perspectives. We exploring a ligand development strategy is based oligomers with discrete folding propensities ("foldamers"); we target cleft the cancer-associated protein Bcl-xL because this system well characterized structurally. In vivo, binds α-helical segments (BH3 domains) other proteins. evaluated several types helical foldamer, built entirely β-amino acid residues or...
Alzheimer's disease (AD) is a neurodegenerative disorder pathologically characterized by extensive extracellular deposition of amyloid-β (Aβ) peptides as senile plaques, and inhibition "amyloidogenic" amyloid precursor protein (APP) processing γ-secretase an important strategy for prevention treatment AD. Here we show that β-peptide foldamers designed to adopt 12-helical conformation in solution are potent specific inhibitors γ-secretase. Subtle modifications disrupt helicity substantially...
Oxidations of alkanes, alkenes, and aromatic rings with pyridine N-oxides are efficiently catalyzed by ruthenium porphyrins under mild conditions. We show here that the oxidation N-acyl cyclic amines RuIVtetraarylporphyrin dichloride-2,6-substituted directly gives amino acids in modest to good yield via oxidative C−N bond cleavage. N-Acylpyrrolidines N-acylpiperidines were converted N-acyl-γ-aminobutyric N-acyl-δ-aminovaleric acids, respectively. This type reaction is a novel one which...
Antioxidant therapies have been considered for a wide variety of disorders associated with oxidative stress, and synthetic catalytic scavengers reactive oxygen species would be clinically superior to stoichiometric ones. Among them, salen–manganese complexes (Mn(Salen)) seem promising, because they exhibit dual functions, i.e. superoxide dismutase- catalase-mimetic activities. We developing enzyme-mimetic Mn(Salen) bearing functional group that enhances their activity. Here, we describe the...
Longer- and/or branched-chain polyamines are unique polycations found in thermophiles. N(4)-aminopropylspermine is considered a major polyamine Thermococcus kodakarensis. To determine whether quaternary branched penta-amine, N(4)-bis(aminopropyl)spermidine, an isomer of N(4)-aminopropylspermine, was also present, acid-extracted cytoplasmic were analyzed by high-pressure liquid chromatography, gas chromatography (HPLC), and chromatography-mass spectrometry. N(4)-bis(aminopropyl)spermidine...
ADVERTISEMENT RETURN TO ISSUEPREVNoteNEXTAn Efficient Route to Either Enantiomer of trans-2-Aminocyclopentanecarboxylic AcidPaul R. LePlae, Naoki Umezawa, Hee-Seung Lee, and Samuel H. GellmanView Author Information Department Chemistry, University Wisconsin, Madison, Wisconsin 53706-1396 [email protected]Cite this: J. Org. Chem. 2001, 66, 16, 5629–5632Publication Date (Web):July 11, 2001Publication History Received12 March 2001Published online11 July inissue 1 August...
We have studied the interaction of β‐17, a potent synthetic antimicrobial β‐peptide, with phospholipids. find that unlike other peptides such as magainin II, β‐17 facilitates formation nonbilayer phases, indicating peptide promotes negative curvature. Studies liposomal leakage also indicate different mode membrane relative to but both and binding show like has strong affinity for membranes containing anionic lipids. This is likely be an important factor contributing specificity β‐peptide.
The interaction between the HIV-1 Tat protein and TAR RNA element in nascent viral genomic transcript is required for replication. An 11-residue β-peptide (1), an all-β homologue of Arg-rich region 47−57, binds with Kd = 29 ± 4 nM. A control (2) which all Arg side chains are replaced by Lys shows increased affinity but decreased specificity wild-type vs bulge-deleted RNA, as do α-peptide analogues 1 2.
Abstract Scholarisine A, isolated from the leaves of Alstonia scholaris , is a monoterpene indole alkaloid with an unprecedented cage‐like structure. In this paper, preparation distinctive core skeleton scholarisine A described. The key feature synthetic strategy intramolecular oxidative coupling reaction at late stage to construct 10‐oxa‐tricyclo[5.3.1.0 3, 8 ]undecan‐9‐one structure fused indolenine. Intramolecular by using N ‐iodosuccinimide gave carbon framework in moderate yield, which...
Porphyrin complexes of iron, manganese and cobalt catalysed reductive dimerization alkenes with NaBH4 under N2O. The reaction system using FeIII porphyrin generated an FeI intermediate that reduced N2O to regenerate porphyrin.
Abstract Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disorder. Despite its severity, there are no effective treatments because of the complexity pathogenesis. As one underlying mechanisms Cu, Zn superoxide dismutase ( SOD1 ) gene mutation-induced ALS, mutants (SOD1 mut commonly interact with an endoplasmic reticulum-resident membrane protein Derlin-1, triggering motoneuron death. However, importance SOD1-Derlin-1 interaction in vitro human model and vivo mouse...
The dye-sensitized photovoltaic cells were prepared by using donor−acceptor dyads derived from fluorescein. measurements performed a standard two-electrode system consisting of working electrode and Pt sputtered in air-saturated methoxyacetonitrile containing 0.5 M iodide 0.05 I2. xanthene the charge-separation type exhibit significant enhancement photoelectrochemical performance as compared with those fluorescein without unit. overall power conversion efficiency (η = 1.6%) has been attained...
A new Mn(Salen) complex bearing an ureido group as auxiliary that is three-dimensionally fixed by a cyclopentane ring fused to the Salen structure was developed. This compound exhibited considerably higher catalase-like activity than original Mn(Salen), i.e., cyclopentane-fused without auxiliary, under near-physiological conditions.
Substrate-selective inhibition or modulation of the activity γ-secretase, which is responsible for generation amyloid-β peptides, might be an effective strategy prevention and treatment Alzheimer's disease. We have shown that helical β-peptide foldamers are potent specific inhibitors γ-secretase. Here we report identification target site by using a photoaffinity probe. The photoprobe directly specifically labeled N-terminal fragment presenilin 1, in initial substrate docking predicted to...