Publications by authors named "Sun Ho Jung"

A zirconium complex containing an N,O-chelate and alkylamide ligand has great potential for application in atomic layer deposition (ALD). However, the synthesis of this mononuclear Zr complex remains a major challenge because of the highly electrophilic nature and rich coordination of the Zr(IV) atom. Herein, a nonclassical and highly effective route for synthesizing the mononuclear N,O-chelate Zr complex was envisaged and verified using rationally designed reactions, involving the ring-opening insertion of epoxide into tetrakis(dimethylamido)zirconium(IV) (TDMAZ) at room temperature.

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A cue for long-range vision allows mosquitoes to identify hosts and differentiate the ecological niches (e.g., habitats).

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Color generation based on strategically designed plasmonic nanostructures is a promising approach for display applications with unprecedented high-resolution. However, it is disadvantageous in that the optical response is fixed once the structure is determined. Therefore, obtaining high modulation depth with reversible optical properties while maintaining its fixed nanostructure is a great challenge in nanophotonics.

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To clarify the microscopic effects of solvents on the formation of the Li(+)-O2(–) process of a Li–O2 battery, we studied the kinetics and thermodynamics of these ions in dimethyl sulfoxide (DMSO) and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMI-TFSI) using classical molecular dynamics simulation. The force field for ions–solvents interactions was parametrized by force matching first-principles calculations. Despite the solvation energies of the ions are similar in both solvents, their mobility is much higher in DMSO.

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Although the programmed degradation of biocompatible films finds applications in various fields including biomedical and bionanotechnological areas, coating methods have generally been limited to be substrate-specific, not applicable to any kinds of substrates. In this paper, we report a dopamine derivative, which allows for both universal coating of various substrates and stimuli-responsive film degradation, inspired by mussel-adhesive proteins. Two dopamine moieties are linked together by the disulfide bond, the cleavage of which enables the programmed film degradation.

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Chalcopyrite CuInSe2 (CIS) nanoparticles were synthesized in oleic acid, 1-octadecene, oleyl amine and tetraethylene glycol at temperature above 200 degrees C. Depending on the solvent used and reaction temperature, the obtained nanoparticles had different shapes, sizes, chemical compositions, and crystal and thermal properties. CIS powders synthesized in oleic acid, 1-octadecene and oleyl amine above 200 degrees C exhibited chalcopyrite structure.

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In the title salt, C17H19N4 (+)·PF6 (-), the two pyridine rings of the cation are inclined to one another by 15.89 (8)°, and inclined to the imidazole ring by 65.05 (10) and 64.

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A series of novel indene N-oxide derivatives were prepared by various synthetic methods and evaluated for their ability to activate PPARgamma. The best PPARgamma agonist in this series was 9h, which showed an EC(50) value of 15 nM.

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Inhibitors of dipeptidyl peptidase IV (DPP-IV) have been shown to be effective treatments for type 2 diabetes. A series of beta-aminoacyl-containing cyclic hydrazine derivatives were synthesized and evaluated as DPP-IV inhibitors. One member of this series, (R)-3-amino-1-(2-benzoyl-1,2-diazepan-1-yl)-4-(2,4,5-trifluorophenyl)butan-1-one (10f), showed potent in vitro activity, good selectivity and in vivo efficacy in mouse models.

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The asymmetric synthesis of chiral piperazinylpropylisoxazoline analogues, (R)-(+)-1, 2 and (S)-(-)-1, 2 was accomplished through a seven-step sequence of reactions, which involved asymmetric 1,3-dipolar cycloaddition, alkyl chain extension, and reductive amination as key reactions. Chiral ligands (R)-(+)-1, 2 exhibited the higher binding affinity and selectivity for the D(3) receptor over the D(4) receptor than (S)-(-)-1, 2 ligands.

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Agonists of peroxisome proliferator-activated receptor gamma (PPAR gamma) are of interest as a treatment for diabetes, which prompted the identification of a new class of non-TZD PPAR gamma agonist. Moreover, compound 14c has displayed the most active agonistic activity with an EC50 value of 50 nM, in addition to exhibiting a new binding mode in the X-ray cocrystal structure.

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In the continuation of efforts to modify the structure of our novel DP-IV inhibitors, a series of pyrazolidine derivatives with heteroaryl urea was synthesized and evaluated for their ability to inhibit dipeptidyl peptidase IV (DP-IV).

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A new series of cyano-pyrazoline derivatives with secondary amine at P-2 site was synthesized through achiral and chiral synthetic methods and evaluated for their ability to inhibit dipeptidyl peptidase IV (DP-IV). Compound 5i revealed good in vivo efficacy (ED50: 4.1 mg/kg; in vivo DP-IV inhibition).

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1-(2-ethoxy-phenyl)-4-[3-(3-thiophen-2-yl-isoxazolin-5-yl)-propyl]-piperazine (KCH-1110), has a high affinity for human dopamine D3 (hD3) receptor (Ki=1.28 nM) with about 90-fold selectivity over the human dopamine D2L (hD2L) receptor. Antipsychotic or antidopaminergic activity of KCH-1110 was investigated in the models for the positive symptoms of schizophrenia, apomorphine-induced climbing and cocaine-induced hyperlocomotion, in mice.

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A new series of 1,2-naphthoquinone derivatives was synthesized by various synthetic methods and evaluated for their ability to inhibit protein tyrosine phosphatase 1B (PTP1B). 1,2-Naphthoquinone derivatives with substituent at R(4) position showed submicromolar inhibitory activity, and compound 24 demonstrated 10- to 60-fold selectivity against the tested phosphatases. Also, several 4-aryl-1,2-naphthoquinone derivatives with substituents at R(3), R(6), R(7), or/and R(8) showed submicromolar inhibitory activity and good plasma stability.

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