• 대한화학회지
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• 제59권3호
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• pp.215-224
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• 2015

Unsymmetrical tetradentate Schiff base N-(2-hydroxy-5-methylacetophenone)-N'-(2-hydroxy acetophenone) ethylene diamine (H₂L) and its complexes with Cr(III), Mn(II), Fe(III), Co(II), Ni(II) and Cu(II) have been synthesized and characterized by elemental analyses, magnetic susceptibility measurements, IR, electronic spectra and thermogravimetric analyses. ¹H, ¹³C-NMR and FAB Mass spectra of ligand clearly indicate the presence of OH and azomethine groups. Elemental analyses of the complexes indicate that the metal to ligand ratio is 1:1 in all complexes. Infrared spectra of complexes indicate a dibasic quadridentate nature of the ligand and its coordination to metal ions through phenolic oxygen and azomethine nitrogen atoms. The thermal behavior of these complexes showed the loss of lattice water in the first step followed by decomposition of the ligand in subsequent steps. The thermal data have also been analyzed for the kinetic parameters by using Horowitz-Metzger method. The dependence of the electrical conductivity on the temperature has been studied over the temperature range 313-403 K and the complexes are found to show semiconducting behavior. XRD and SEM images of some representative complexes have been recorded. The antimicrobial activity of the ligand and its complexes has been screened against various microorganisms and all of them were found to be active against the test organisms. The Fe(III) and Ni(II) complex have been tested for the catalytic oxidation of styrene.

• Preventive Nutrition and Food Science
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• 제6권4호
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• pp.230-234
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• 2001

The extract of Ulmus davidiana var. japonica cortex has known as natural anti-inflammatory substance in East Asia. For the identification of antimicrobial substance, it was extracted by using methanol and fractionated by using different organic solvents. The fraction of butanol was represented the highest antimicrobial activities. Therefore, the butanol fraction was purified and identified the chemical structure by $^1$H and $^{13}$ C-NMR spectra, FT-IR and EI/MS spectroscopies. The isolated antimicrobial substance was identified as cis-2-[3,4-dihydroxy phenyl]-3,4-dihydro-2H-1-benzopyran-3,5,7-triol, which has commonly known as (-)epicatechin. Its minimum inhibitory concentrations (MICs) against Staphylococcus aureus and Listeria monocytogenes were shown as 100 $\mu\textrm{g}$/mL, respectively.

• Bulletin of the Korean Chemical Society
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• 제30권10호
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• pp.2227-2232
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• 2009

Novel polythiol materials of urethane lens series for plastic optical lens were synthesized from polyol materials via thioisouronium of thiourea with c-HCl in refluxing aqueous solution, in which polythiol material was carried out from hydrolysis of thioisouronium by ammonia water. Their structure properties were identified by EA, EI-MS, FT-IR, $^1H\;and\;^{13}C$ NMR spectroscopies and TGA. Their ophthalmic lenses as polythiourethane material were prepared by thermal curing to an injected glass mold using the evenly solutions of diisocyanates series (TDI, XDI, HDI or IPDI) with polythiols. Polythiourethane shows that the strong stretching mode for SH group of polythiol disappeared in FT-IR spectra after thermosetting polymerization. Thermal deformation starting temperature of ophthalmic lenses was determined by TMA. Ophthalmic lenses made from characteristic polythiol and diisocyanate series have transparency, colorless and good impact strength, in which thermal resistance and impact strength of ophthalmic lenses were influenced by diisocyanate series. Physical properties of ophthalmic lens have contrast thermal resistance with impact strength. The property of thermal resistance and impact strength for respective ophthalmic lenses was examined by TMA and drop ball test.

• Journal of Microbiology and Biotechnology
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• 제15권3호
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• pp.626-632
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• 2005

A new bacterium BL-2 excreting a novel cationic polyglucosamine biopolymer was isolated from the spoiled leaves of Chinese cabbage and identified as Enterobacter sp. BL-2. The isolated Enterobacter sp. BL-2 was cultivated in pH-stat fed-batch culture using acetic acid as the feeding stock at pH 8.0, resulting in 17.11 g/l of cells and 1.53 g/l of an extracellular biopolymer after 72 h. The excreted biopolymer was purified by a three-step procedure, involving ethanol precipitation and deproteinizations, to a nearly homogeneous state, and its molecular weight was found to be 106 kDa. It was composed of glucosamine, rhamnose, and galactose at a molar ratio of 86.4:1.6:1.0, respectively, indicating a rarely found novel high-glucosamine-containing biopolymer. The FT-IR and $^{13}C-NMR$ spectra of the novel cationic polyglucosamine biopolymer PGB-l revealed a close identity with chitosan from crab shell. It can effectively flocculate various suspended solids, including kaolin clay, $Ca(OH)_2,\;Al_{2}O_3$, active carbon, microbial cells, and acidic dyes.

• 한국응용과학기술학회지
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• 제12권1호
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• pp.35-41
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• 1995

The Hydrolysis kinetics of Benzoyl Styrene Derivatives[I]${\sim}$[IV] was investigated by ultraviolet spectrophotometery in 5% dioxane-$H_2O$ at $40^{\circ}C$. The structure of these compounds were ascertained by means of ultraviolet, melting point, IR and NMR spectra. The rate equations which were applied over a wide pH range (pH $1.0{\sim}13.0$) were obtained. The substituent effects on Benzoyl styrene derivatives[I]${\sim}$[IV] were studied, and the hydrolysis were facilitated by electron attracting groups. On the basis of the rate equation and substitutent effect and final product, the plausible hydrolysis reaction mechanism was proposed: At pH 1.0${\sim}$pH 9.0, not relevant to the hydrogenl ion concentration, neutral $H_2O$ molecule competitively attacked on the double bond. By contrary. Above pH 9.0, It was proportional to concentration of hydroxidel ion.

• Macromolecular Research
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• 제11권1호
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• pp.47-52
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• 2003

The objective of this study was to develop a polymeric drug delivery system for camptothecin (CPT), capable of improving its therapeutic index and reducing its side effects. A monomeric conjugate, 3,6-endo-methylene-1,2,3,6-tetrahydrophthalimidoethanoylcamptothecin in (ETECPT) between CPT and 3,6-endo-methylene-1,2,3,6-tetrahydrophthalimidoethanoic acid was synthesized. Its homo-and copolymer with acrylic acid (AA) were prepared by photopolymerization using 2,2-dimethoxy-2-phenylacetophenone (DMP) as a photoinitiator. The monomer and its polymers were characterized by IR, $^1$H- and $^{13}$ C-NMR spectra. The ETECPT content in poly(ETECPT-co-AA) obtained by elemental analysis was 82 wt%. The number-average molecular weights of the polymers determined by gel permeation chromatography were as follows: M$_{n}$ = 11,400 for poly(ETECPT), M$_{n}$ = 17,900 for poly(ETECPT-co-AA). The $IC_{50}$/ values of ETECPT and its polymers against cancer cells were much larger than that of CPT. Our results from the in vivo antitumor activity indicated that all polymers show high antitumor activity than CPT at a dose of 100 mg/kg./kg.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1988년도 학술대회지
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• pp.122-128
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• 1988

폴리아세칠랜계 화합물이 함유된 인삼의 석유 에텔 추출물은 시험관내 실험에서 Sarcoma 180, Walker carcinosarcoma 256, $L_{1210}leukemic$ lympocyte의 성장을 억제한다. 우리는 석유 ether 추출물로 부터 몇가지 포리아세틸렌계 화합물을 분리하여 화학구조를 밝혔다. UV, IR $^{1}H$ NMR, $^{13}C$ NMR, EI mass, CI mas, 원소분석과 산화 또는 산촉매 가수분해와 같은 화학적인 방법으로 얻어진 자료에 근거하여 이들은 heptadeca-1,9-dien-4,6-diyn-3-ol, hepatadeca-l-en-4.6-diyn-9,10-epoxy-3-ol 및 hepatadeca-1,8-dien-4,6-diyn-3,10-diol로 밝혀 졌다.

• 생명과학회지
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• 제14권1호
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• pp.91-97
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• 2004

앞선 연구의 구조적 특성을 근거로 하여, 한 분자내에 MES 유발경련에 작용하는 cyclicimide의 구조를 포함하면, 그들의 구조가 경련 유발 수용체들에 상호 보완적으로 작용, MES및 PTZ유발 경련에 모두 작용할 수 있는 적용 범위가 넓은 항경련성 화합물이 될 수 있을 것으로 생각하여 N-acyl-$\alpha$-aminosuccinimide 1과 N-acyl-$\alpha$-aminoglutar- imide 2 유도체를 합성하였다. 먼저 (R)-2-benzyloxy carbonylamino-succinic acid 3을 출발 물질로 하여 N-acyl-a-aminosuccinimide 1 유도체인 (R)-Benzoic acid 4-benzyloxycarbonyl-amino-2-oxo-pyrrolidin-l-yl ester 6a, (R)4-nitro-benzoic acid 4-benzyloxycarbon-ylamino-2-oxo-pyrrolidin-1-yl ester 6b, (R)-4-nitro-benzoic acid 4-benzyloxycarbonylamino-2-oxo-pyrrolidin-1-yl ester 6c, 그리고 (R)-propionic acid 4-benzyloxycarbonylamino-2-oxo-pyrrolidin-1-yl ester 64를 합성하였다 또한 (R)-3-car-bobenzyloxy-aminoglutarrnic acid 7를 출발물질로 하여 N-acyl-$\alpha$-aminoglutarimide 2유도체인 (R)-(3-Benzyloxycarbonyl-amino-2,6-dioxo-piperidin-1-yloxy)-acetic acid methyl ester 10a, (R)-(3-benzyloxyarbonylamino-2,6-dioxo-piperidin-1-yloxy)-acetic acid ethyl ester l0b, 그리고 (R)-2-(3-benzylox-ycarbonylanino-2,6-dioxo-piperidin-1-yloxy)-propionic acid methyl ester l0c를 합성하였다. 합성된 화합물 6a, 6b, 6c, 6d, 10a, lOb, l0c에 대한 활성평가는 각 단계별 MES test와 PTZ test의 항경련 활성 시험 방법을 가지고 실험할 예정이다.

• Restorative Dentistry and Endodontics
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• 제21권2호
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• pp.642-651
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• 1996

The purpose of this study was to evaluate the relationship between monomer compositions and the changes in the degree of conversion in the various layers of composites after additional heat curing. Four types of composites and 3 types of inlay ovens were used in this study. Composite was placed in a 4-mm thick teflon mold, and light cured from the top for 60 seconds. Ten samples were prepared for each composite ; 5 of these were additionally heat cured in an inlay oven as the manufacturer recommended. After light curing or light and heat curing, the samples were sectioned into four parts and assigned to groups A, B, C, or D according to their distance from the light source. These sections were then thinned to 50-$70{\mu}m$, and these wafers were analyzed with a Fourier Transform Infrared Spectrometer(FI-IR) to determine the degree of conversion. A standard baseline technique was used to calculate the degree of conversion. $^{13}C$ NMR spectra of bis-GMA, TEGDMA and bis-EMA, were acquired using a Varian Gemini spectrometer operated at 200 MHz. $CDCl_3$ solvent was used for qualitative analysis. The degree of conversion was affected by bis-GMA : TEGDMA ratio but it seemed to be also affected by other factors. When the composites were heat cured, significant increases in the degree of conversion were noted throughout the samples, but the amount of increase differed between materials. Thus, clinical performance of a heat-treated composite inlay may be different depending on materials.

• 대한화학회지
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• 제55권6호
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• pp.919-925
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• 2011

A new series of manganese(II), iron(III) and cobalt(III) complexes of 14-membered macrocyclic ligand, (3,6,10,13,16,19-hexaazabicyclo[6.6.6]icosane-1,8-diamine) have been prepared and characterized by elemental analyses, IR, UV-VIS, $^1H$- and $^{13}C$- NMR spectra, magnetic susceptibilities, conductivities, and ESR measurements. Molar conductance measurements in DMF solution indicate that the complexes are electrolytes. The ESR spectrum for cobalt(III) complex in $CD_3OD+10%D_2O$ after exposure to $^{60}Co-{\gamma}$-rays at 77 K using a 0.2217 M rad $h^{-1}$ vicrad source showed $g_{\perp}$ > $g_{\parallel}$ > $g_e$, indicating that, the unpaired electron site is mainly present in the $d_z2$ orbital with covalent bond character. In this case, the ligand hyperfine tensors are nearly collinear with ${\gamma}$-tensors, so there is no major tendency to bend. Therefore, little extra delocalization via the ring lobe of the $dz^2$ orbital occurs. However, the ESR spectrum in solid state after exposure to $^{60}Co-{\gamma}$-rays at 77 K showed $g_{\parallel}$ > $g_{\perp}$ > $g_e$, indicating that, the unpaired electron site is mainly present in the $d_x2_{-y}2$ ground state as the resulting spectrum contains a large number of randomly oriented molecules provided that, the principle directions of g and A tensors. Manganese (II) complex 2, $[H_{12}LMn]Cl_4.2H_2O$, showed six isotropic lines characteristic to an unpaired electron interacting with a nucleus of spin 5/2, however, iron(III) complex 3, $[H_{12}LFe]Cl_5.H_2O$, showed spectrum of a high spin $^{57}Fe$ (I=1/2), $d^5$ configuration. The geometry of these complexes was supported by elemental analyses, IR, electronic and ESR spectral studies. Complex 1 showed exploitation in reducing the amount of electron adducts formed in DNA during irradiation with low radiation products.