Publications by authors named "Yong-Wah Kim"

Nanostructured metal oxides with cationic or anionic deficiency find applications in a wide range of technological areas including the energy sector and environment. However, a facile route to prepare such materials in bulk with acceptable reproducibility is still lacking; many synthesis techniques are still only bench-top and cannot be easily scaled-up. Here, we report that the benzyl alcohol (BA)-mediated method is capable of producing a host of nanostructured metal oxides (MO, where M = Ti, Zn, Ce, Sn, In, Ga, or Fe) with inherent nonstoichiometry.

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A novel class of ionic liquids (ILs), exhibiting high selectivity towards boron species as well as the ability to phase separate from water, were synthesized from N-methyl-D-glucamine. The complexation of boric acid/borate with the ILs was confirmed using (11)B NMR.

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Theoretical calculations were carried out for studying the tautomeric protonation of N-methylpiperazine as a prototype six-member aliphatic ring containing a secondary and a tertiary nitrogen atom. The protonation was investigated in three solvents, water, acetonitrile, and dichloromethane. Calculations were performed up to the B3LYP/aug-cc-pvtz and QCISD(T)/CBS levels by applying the IEF-PCM polarizable continuum dielectric solvent model.

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The procedure for the expression and purification of recombinant porcine leukocyte 12-lipoxygenase using Escherichia coli [K.M. Richards, L.

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Lipoxygenase plays a central role in polyunsaturated fatty acid metabolism, inaugurating the biosynthesis of eicosanoids in animals and phytooxylipins in plants. Redox cycling of the non-heme iron cofactor represents a critical element of the catalytic mechanism. Paradoxically, the isolated enzyme contains Fe(II), but the catalytically active form contains Fe(III), and the natural oxidant for the iron is the hydroperoxide product of the catalyzed reaction.

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The positively charged quaternary ammonium cyclodextrin, QA-beta-CD, was previously used as a chiral selector to achieve baseline resolution of two of the dianionic enantiomers of disodium 3-(p-isothiocyanatophenoxy)-3-(p-isothiocyanatophenyl)propane-1,2-disulfate by capillary electrophoresis. The basis of the chiral discrimination between QA-beta-CD and the enantiomers was investigated by (1)H NMR spectroscopy. COSY and NOESY spectra were used to infer the role that molecular interactions and the stereocenters have upon association of QA-beta-CD with the enantiomers.

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The acid H(2)B(12)(OH)(12) can be isolated as a crystalline solid by protonation of the hydroxylated borane anion, B(12)(OH)(12)(2)(-). This acidic compound has low solubility in water, conducts protons in the solid state, and has thermal stability to a temperature of 400 degrees C. The conductivity mechanism is a Grotthuss mechanism with a low activation enthalpy (9-13 kcal/mol).

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Lipoxygenase catalysis depends in a critical fashion on the redox properties of a unique mononuclear non-heme iron cofactor. The isolated enzyme contains predominantly, if not exclusively, iron(II), but the catalytically active form of the enzyme has iron(III). The activating oxidation of the iron takes place in a reaction with the hydroperoxide product of the catalyzed reaction.

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