• Korean Journal of Crystallography
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• v.16 no.1
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• pp.43-53
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• 2005

The dihydrido P-C-P pincer complex, $IrH_2{C_6H_3-2,6-(CH_2PBu_2^t)_2}$ (1), was successfully prepared from the reaction of the hydrochloride complex, $IrClH (C_6H_3-2,6-(CH_2PBu_2^t)_2}$, and super acid $(LiBEt_3H)$ under 1 atm of hydrogen in pentane solution at room temperature and followed by Heating at $130^{\circ}C$ in vacuo. Jensen recently found that the dihydrido P-C-P pincer complex 1 is a highly active homogeneous catalyst for the transfer dehydrogenation of alkanes with unusual longterm stability at temperatures as high as $200^{\circ}C$. The treatment of dihydrido complex 1 with nitrogen, water, carbon dioxide, and carbon monoxide in presence of tert-butylethylene (the) at room temperature in an appropriate solution gave the dinitrogen complex, $[Ir{C-6H_3-2,6-(CH_2PBu_2^t)_2}]_2({\mu}-N_2)$ (2), the hydrido hydroxyl complex, $IrH(OH){C_6H_3-2,6-(CH_2PBu_2^t)_2}$ (3), the carbon dioxide complex, $Ir({\eta}^2-CO_2) {C_6H_3-2,6-(CH_2PBu_2^t)_2}$ (including the bicarbonate complex, $IrH({\kappa}^2-O_2COH){C_6H_3-2,6-(CH_2PBu_2^t)_2}\;(4))$, and the carbonyl complex, $Ir(CO) {C_6H_3-2,6-(CH_2PBu_2^t)_2}\;(5)$ (including the carboxyl complex, $IrH(C(O)OH) {C_6H_3-2,6-(CH_2PBu_2^t)_2}\;(6))$, in good yield, respectively. These P-C-P iridium complexes were isolated and characterized by $^1H,\;^{13}C,\;^{31}P\; NMR$, and IR spectroscopy. In addition, the complexes (1-6) were characterized by a single crystal X-ray crystallography. These complexes account for these small molecules' inhibition of dehydrogenation of alkanes catalyzed by the dihydrido complex 1.

• Journal of Integrative Natural Science
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• v.2 no.3
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• pp.190-193
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• 2009

Bis(silyl)palladinum(II) and -platinum(II) complexes are key intermediates for the synthesis of organic silyllated compounds by the Pd or Pt-catalyzed reactions. Reactions of dialkylpalladinum and -platinum complexes with diphenylsilane gave the bis(silyl)palladinum and -platinum complexe in moderate to good yields. Isolated complexes were characterized by $^1H$, $^{13}C$ and $^{31}P$-NMR spectroscopy and elemental analyses. Some of the complexes were determined by X-ray crystallographic studies.

• Macromolecular Research
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• v.16 no.7
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• pp.620-625
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• 2008

A novel nitrogen-phosphorus compound, diphenyl piperazine-1,4-diylbis(methylphosphinate)(DPPMP) was synthesized via a two step reaction and its flame retarding efficiency as a single component additive was investigated. The success of synthesis was confirmed by FTIR and $^1H$ and $^{31}P$ NMR analysis. The product was mixed with polycarbonate (PC), poly(butylene terephtalate) (PBT), ethylene-vinyl-acetate copolymer (EVA), and acrylonitrile-butadiene-styrene copolymer (ABS). The flame-retarding efficiency was evaluated using the limiting oxygen index (LOI) and the UL-94 vertical test methods. The addition of DPPMP enhanced the flame retardancy of the polymers and the V-0 ratings were obtained for the polymers examined in this study at a loading of 7-30 wt%. The gas-phase flame retardancy mode of action was suggested for this material from the thermogrametry experiment results.

• Journal of the Korean Chemical Society
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• v.55 no.6
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• pp.952-959
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• 2011

Novel phosphorylated derivatives of ribavirin 5-16 were synthesized by the reaction of 4-nitrophenyl phosphorodichloridate with various amino acid esters in the presence of triethylamine in dry tetrahydrofuran through the intermediates 3. On further reaction of 3 with ribavirin in THF and pyridine in the presence of TEA afforded the title compounds 5-16. Their structures were characterized by IR, $^1H$, $^{13}C$, $^{31}P$ NMR and mass spectral analyses. All the title compounds were found to exhibit potent in vitro anticancer activity against MCF-7 breast cancer cell lines.

• Bulletin of the Korean Chemical Society
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• v.17 no.11
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• pp.1031-1036
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• 1996

The synthesis and characterization of diastereomeric dodecanucleotides, d[GATCp(S)TCGAGATC], containing recognition sequence of the XhoI restriction endonuclease with a phosphorothioate internucleotidic linkage the cleavage site are described. Rp and Sp form of diastereomerically pure dinucleoside phosphorothioates d[Cp(S)T] were presynthesized and used for the addition to the growing oligonucleotide chain as a block. The stereochemistry of dinucleoside phosphorothioate was assigned by 31P NMR spectroscopy, enzyme digestion, and reverse-phase HPLC. XhoI restriction endonuclease cut only Rp diastereomer d[GATCp(S))TCGAGATC]. The rate of hydrolysis is slower than that of the unmodified dodecamer d[GATCTCGAGATC]. The phosphorothioate nucleotide is using for determination of the stereochemical course of the XhoI catalyzed reaction.

• Bulletin of the Korean Chemical Society
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• v.11 no.3
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• pp.238-240
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• 1990

$^{31}P${$^1H$} nuclear Overhauser effects (NOEs) have been obtained for complexes formed between apolipoprotein B (apo B) and dipalmytoylphosphatidylcholine (DPPC) vesicles. NOE measurements have been conducted with broad-band irradiation of the entire $^1H$ spectrum in order to identify the proton source of the NOE. In a unilamellar vesicle formed spontaneously upon mixing aqueous suspensions of long-chain phospholipid with small amount of short-chain lecithin, the maximum NOE occurs at the N-methyl proton resonance position of the choline moiety. With addition of cholesterol to vesicles, the position of the NOE maximum shifts further away from the choline methyl frequency. For the ternary apo B-vesicle-cholesterol complex, the position of the maximum NOE lies halfway between those in vesicles with and without cholesterol.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2007.11a
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• pp.27-31
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• 2007

This study relates to low and medium molecular weight isoflavone-${\beta}$-D-glucan produced by submerged liquid culture of Agaricus blazei, a method of producing the isoflavone-B-D-glucan using autolysis enzyme of Agaricus blazei mycelia, and use of the isoflavone-B-D-glucan for anti-cancer and immunoenhancing effect. In acordance with one aspect of the present study, it deals with a method of producing isoflavone-${\beta}$-D-glucan, which comprises the followings; 1) culturing and separating mushroom mycelia, 2) producing low-medium molecular weight isoflavone-${\beta}$-D-glucan from high molecular weight one. The cytotoxicity on human cnacer cell line (Caco-2, MCF-7), the expression of Cyclin D, Bcl-2, Bax protein, p21 protein, p53 protein in MCF-7 cells assessed by SDS-PAGE and immunoblotting, and other immuno related factors such as TNF-${\alpha}$ and IL-1B activities were examined. Structural identification of isoflavone-${\beta}$-D-glucan which showed cytotoxicity against cancer cell and immunoenhancing effects was carried by separation with DEAE-cellulose column chromatography, TLC, HPLC, IR, NMR. Clinical test for the cancer patients (n=119) for 6 month was carried out, and immunoenhancing factors (NK. cell number, ratio of T4/T8) were checked. We concluded the identified isoflavone-${\beta}$-D-glucan has immuno enhancing effects and could be useful for cancer chemoprevention.

• The Plant Pathology Journal
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• v.23 no.3
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• pp.180-186
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• 2007

The biocontrol agent, Serratia plymuthica A21-4, has been developed for controlling pepper Phytophthora blight. Serratia plymuthica A21-4 strongly inhibits the mycelial growth, zoospore formation, and cyst germination of Phytophthora capsici in vitro. The application of a cell suspension of strain A21-4 to pepper plants in pot experiments and in greenhouse successfully controlled the disease. The bacteria produced a potent antifungal substance which was a key factor in the suppression of Phytophthora capsici. The most active chemical com-pound was isolated and purified by antifungal activity-guided fractionation. The chemical structure was identified as a chlorinated macrolide $(C_{23}H_{31}O_8Cl)$ by spectroscopic (UV, IR, MS, and NMR) data, and was named macrocyclic lactone A21-4. The active compound significantly inhibited the formation of zoosporangia and zoospore and germination of cyst of P. capsici at concentrations lower than $0.0625{\mu}g/ml$. The effective concentrations of the macrocyclic lactone A21-4 for $ED_{50}$ of mycelial growth inhibition were $0.25{\mu}g/ml,\;0.25{\mu}g/ml,\;0.30{\mu}g/ml \;and\;0.75{\mu}g/ml$ against P. capsici, Pythium ultimum, Sclerotinia sclerotiorum and Botrytis cinerea, respectively.

• Bulletin of the Korean Chemical Society
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• v.16 no.6
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• pp.524-528
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• 1995

The reaction of [IrCl(cod)]2 with ppol ligand, Ph2PCH2CH2CH2P(Ph)CH2CH2CH=CH2, in ethanol gives an iridium complex, whose structure is converted from an ionic form, [Ir(cod)(ppol)]Cl·2C2H5OH (1),in polar solvents (ethanol, methanol and acetonitrile), to a molecular form, [IrCl(cod)(ppol)], in non-polar solvents (benzene and toluene). The cationic complexes, [Ir(cod)(ppol)]AsF6·1/2C2H5OH and [Ir(cod)(ppol)]PF6·1/2CH3CN, were prepared to compare with the ionic form by 31P NMR spectroscopy. When carbon monoxide is introduced to 1, cod is replaced by CO to give the 5-coordinated complex, [IrCl(CO)(ppol)]. Hydrogenation of 1-octene was not successful in the presence of 1. In order to verify the reason for 1 not behaving as a good catalyst for hydrogenation, electrophilic reactions with HCl, I2 and HBF4·etherate were performed, which yielded the oxidative addition product, [IrHCl2(ppol)], the substitution product, [IrI(cod)(ppol)], and another cationic product, [Ir(cod)(ppol)]BF4, respectively. Thus, the iridium complex is not sufficiently basic to activate hydrogen atoms or the olefin of the ppol ligand.

• Journal of Microbiology and Biotechnology
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• v.31 no.5
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• pp.696-704
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• 2021

Levan is an industrially important, functional biopolymer with considerable applications in the food and pharmaceutical fields owing to its safety and biocompatibility. Here, levan-type exopolysaccharide produced by Pantoea agglomerans ZMR7 was purified by cold ethanol precipitation and characterized using TLC, FTIR, ¹H, and ¹³C NMR spectroscopy. The maximum production of levan (28.4 g/l) was achieved when sucrose and ammonium chloride were used as carbon and nitrogen sources, respectively, at 35℃ and an initial pH of 8.0. Some biomedical applications of levan like antitumor, antiparasitic, and antioxidant activities were investigated in vitro. The results revealed the ability of levan at different concentrations to decrease the viability of rhabdomyosarcoma and breast cancer cells compared with untreated cancer cells. Levan appeared also to have high antiparasitic activity against the promastigote of Leishmania tropica. Furthermore, levan had strong DPPH radical scavenging (antioxidant) activity. These findings suggest that levan produced by P. agglomerans ZMR7 can serve as a natural biopolymer candidate for the pharmaceutical and medical fields.