• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1650-1656
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• 2011

A series of potent tricyclic derivatives with a non-aromatic amide as potent PARP-1 inhibitors were successfully synthesized and their PARP-1 inhibitory activity was evaluated. Among the derivatives, 2-(1-propylpiperidin-4-yloxy)-7,8,9,10-tetrahydrophenanthridin-6(5H)-one 23c displayed potent activity in a PARP-1 enzymatic assay and cell-based assay ($IC_{50}$ = 0.142 ${\mu}M$, $ED_{50}$ = 0.90 ${\mu}M$) with good water solubility. Further, molecular modeling studies confirmed the obtained biological results.

• Journal of Applied Biological Chemistry
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• v.58 no.1
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• pp.25-29
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• 2015

The determination of the optimum conditions for the conversion of ergosterol to vitamin $D_2$ in shitake mushrooms (Lentinula edodes) was studied using response surface methodology (RSM). The effects of the three main variables ambient temperature ($20-40^{\circ}C$), exposure time (60-180 min), and irradiation intensity ($0.6-1.8W/m^2$) were investigated. According to the RSM ridge analysis, the optimum conditions were as follows: ambient temperature of $34.2^{\circ}C$, exposure time of 175.6 min, and irradiation intensity of $1.41W/m^2$. Under these optimum conditions, the maximum vitamin $D_2$ content of $117.93{\mu}g/g$ in shitake mushrooms was obtained, which agreed fairly well with the predicted value of $122.60{\mu}g/g$.

• Applied Chemistry for Engineering
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• v.7 no.2
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• pp.350-355
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• 1996

Poly(AA-co-EGDMA) microgels were prepared by precipitation polymerization in highly swollen polystyrene gel solution. The polymerization was carried out in selective solvent such as cyclohexane/acetone at $60^{\circ}C$. Poly(AA-co-EGDMA) microgels with various site of $0.18{\sim}0.55{\mu}m$ were obtained from different concentration of polystyrene(PS), concentration of crosslinking agent(EGDMA), ratio of Ps/monomer and volume ratio of solvents. The particle size of poly(AA-co-EGDMA) microgels decreased with increasing the concentration of PS and increased with that of EGDMA.

• Bulletin of the Korean Chemical Society
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• v.27 no.10
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• pp.1597-1600
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• 2006

The mononuclear iron complex 1, $Fe^{III}$(Hbida)Cl($H_2O$), was synthesized using a tripodal tetradentate ligand, N-(benzimidazol-2-ylmethyl)iminodiacetic acid (H3bida), which has two carboxylate groups, one benzimida- zoyl group, and one tertiary amine where it serves as a tetradentate chelating ligand for the octahedral Fe(III) ion. The four equatorial positions of the octahedral complex are occupied by two monodentate carboxylates, a benzimidazole nitrogen, and an oxygen of a water molecule. One of the axial positions is occupied by an apical nitrogen of the Hbida and the other by a chloride anion. The mononuclear octahedral complex 1 mimics the geometry of the key intermediate structure of the catalytic reaction cycle proposed for the FeSODs, which is a distorted octahedral geometry with three histidyl imidazoles, an aspartyl carboxylate, a superoxide anion, and a water molecule. The redox potential of complex 1, $E_{1/2}$ is -0.11V vs. Ag/AgCl (0.12 V vs. NHE), which is slightly lower than those reported for the most FeSODs. The magnetic susceptibility of complex 1 at room temperature is 5.83 $\mu$B which is close to that of the spin only value, 5.92 $\mu$B of high-spin d5 Fe(III).

• YAKHAK HOEJI
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• v.50 no.5
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• pp.326-331
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• 2006

We designed and synthesized new benzylpiperidinyl ether derivatives as beta-amyloid aggregation inhibitors for the development of novel anti-Alzheimer's disease agents. As starting material, 4-hydroxypiperidine was used. For protection of the amine group in piperidine (2), di-tert-butyl dicarbonate was reacted with 4-hydroxypiperidine in the presence of triethylamine. For introduction of benzyl group, benzylbromide was treated with compound 2 in dioxane. After deprotection of Boc group on amine in compound 3, ester (5) was synthesized by addition of ethyl-4-chlorobutyrate. The alcohol 6 was synthesized by hydride reduction of 5 using $LiAlH_4$. To obtain final products (7-14), the alcohol 6 was condensed with each of substituted benzoic acids. To screen beta-amyloid aggregation inhibition of the products, thioflavinT assay was performed using $A{\beta}1-42\;at\;37^{\circ}C$ for 26 h incubation, in vitro. From the result of screening, compound 8, 9, 11 and 12 showed effective activity about $65{\sim}85\;{\mu}M\;as\;IC_{50}$ value. Among the prepared compounds, 4-[4-(benzyloxy)piperidino]butyl-4-chlorobenzoate (8) was the most effective inhibitor having $IC_{50}\;of\;65.4{\mu}M$.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.11 no.3
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• pp.97-105
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• 1997

The aim of this paper is to introduce a design technique of the Two-Degree-of-Freedom(TDF) satellite-tracking control system which has not only the robust stability for a unstructured uncertainty but also the robust performance for a structured uncertainty. This TDF system which can design the feedforward controller KI and the feedback one K independently is designed by , $\mu$-synthesis. The effectiveness of this TDF system is verified and compared with the One-Degree-of -Freedom(ODF) satellitetracking control system by computer simulation.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.19 no.3
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• pp.125-129
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• 2009

The preparation and characterization of niobium carbide crystallites were investigated in this study, and in particular, the effect of preparation conditions were studied on the synthesis of niobium carbides crystallites. For this purpose, various characterization techniques including x-ray diffraction, BET surface area, and oxygen uptake measurements were employed to characterize the synthesized niobium carbide crystallites. The niobium carbide crystallites were prepared using niobium oxide and methane gas or methane-hydrogen mixture. Using x-ray diffraction a lattice parameter of $4.45{\AA}$ and a crystallite size ranging from $52{\AA}$ to $580{\AA}$ was found. BET surface areas ranged from $3.2\;m^2/g$ to $16.6\;m^2/g$ and oxygen uptake values varied from $0.5{\mu}mol/g$ to $6.1{\mu}mol/g$. It was observed that niobium carbide crystallites were active for ammonia decomposition reaction. While the BET surface area increased with increasing the oxygen uptake, the conversion of ammonia decomposition reaction decreased. These results indicated that the ammonia decomposition over these materials was considered to be structure-sensitive.

• Microbiology and Biotechnology Letters
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• v.21 no.4
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• pp.316-321
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• 1993

MCH-201 was isolated from the mycelium of Streptomyces sp. Ba16 as a potent effector on proliferation and morphology of human breast tumor cell line, MCF-7. Morphological change could be observed at concentration between 2.5${\mu}$g/ml and 250pg/ml and showed cytotoxic effect at the concentration of more than 5${\mu}$g/ml. This compound also showed inhibitory effect on DNA synthesis of hepatoma cells, Hepa 1c1c7, and strong cytotoxic effect on proliferation of human tumor cell lines, A549 and XF498.

• Korea-Australia Rheology Journal
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• v.15 no.3
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• pp.117-124
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• 2003

Elastohydrodynamic lubrication (EHL) film is measured under the condition of viscosity index improver added to base oil. In-situ optical contact method using the interference principle make the measuring resolution of ~5 nm possible and enables the measuring range all over the contact area of up to ~300 $\mu\textrm{m}$ diameter. What is more important to the developed method by the author is that the measurement of EHL film thickness is possible in the range from 100 nm to 2 $\mu\textrm{m}$, which is the regime of worst contact failures in precision machinery. Viscosity index improver (VII) is one of the major additives to the modem multigrade lubricants for the viscosity stability against temperature rise. However, it causes shear thinning effects which make the film thickness lessened very delicately at high shear rate (over $10^5 s^{-1}$) of general EHL contact regime. In order to exactly verify the VIIs performance of viscosity stability at such high shear rate, it is necessary to make the measurement of EHL film thickness down to ~100 nm with fine resolution for the preliminary study of viscosity control. In this work, EHL film thickness of VII added lubricant is measured with the resolution of ~5 nm, which will give very informative design tool for the synthesis of lubricants regarding the matter of load carrying capacity at high shear rate condition.

• Parasites, Hosts and Diseases
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• v.56 no.5
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• pp.491-494
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• 2018

Multipurpose contact lens disinfecting solutions (MPDS) are widely used to cleanse and disinfect microorganisms. However, disinfection efficacy of these MPDS against Acanthamoeba cyst remain insufficient. 2, 6-dichlorobenzonitrile (DCB), a cellulose synthesis inhibitor, is capable of increasing the amoebical effect against Acanthamoeba by inhibiting its encystation. In this study, we investigated the possibility of DCB as a disinfecting agent to improve the amoebicidal activity of MPDS against Acanthamoeba cyst. Eight commercial MPDS (from a to h) were assessed, all of which displayed insufficient amoebicidal activity against the mature cysts. Solution e, f, and h showed strong amoebicidal effect on the immature cysts. Amoebicidal efficacy against mature cysts remained inadequate even when the 8 MPDS were combined with $100{\mu}M$ DCB. However, 4 kinds of MPDS (solution d, e, f, and h) including $100{\mu}M$ DCB demonstrated strong amoebicidal activity against the immature cysts. The amoebicidal activity of solution d was increased by addition of DCB. Cytotoxicity was absent in human corneal epithelial cells treated with either DCB or mixture of DCB with MPDS. These results suggested that DCB can enhance the amoebicical activity of MPDS against Acanthamoeba immature cyst in vitro.