• Bulletin of the Korean Chemical Society
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• 제31권2호
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• pp.503-506
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• 2010

• Bulletin of the Korean Chemical Society
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• 제35권7호
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• pp.2077-2080
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• 2014

Cobalt-immobilized SBA-15 6a-c was synthesized from alkyne-attached SBA 5a-c by the reaction with $Co_2(CO)_8$ in toluene. Alkyne group was introduced into amino SBA-15 (4) by imine-linkage or substitution with propargyl bromide to afford iminoalkyne 5a and aminoalkyne 5b, respectively. Meanwhile, alkyne 5c was prepared in one-step by reacting triethoxysilyl hexyne with SBA-15. Dicobalt-complexes 6a-c were characterized by means of FT-IR, solid-state NMR and elemental analysis.

• 대한안전경영과학회지
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• 제1권1호
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• pp.259-272
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• 1999

In order to enhance the selectivity, productivity and yield of methyl fructoside, which was synthesized by enzymatic glycosylation of sucrose and methanol solution, controlling of surface property of solid support using different immobilization procedures optimized microenvironment of immobilized invertase. Silanization and polyethylene imine coating methods were adopted to give a hydrophobic and hydrophilic environment of immobilized invertase. As a result, polyethyleneimine coating method gave higher loading of enzyme, effective activity, and relative activity than silanization method, because it brought on increasing the functional density of amino group and enhancing the conservation of activity by regulating of hydrophilicity. And then, hydrophilic environment was possible to restraint the assessing of methyl fructoside molecule, which was more hydrophobic than sucrose, fructose, and glucose molecule in the reaction mixture, into .the active site of immobilizedinvertase. Consequently, hydrophilic microenvironment of immobilized invertase by polyethyleneimine coating obtained higher yield and productivity with increasing conversion than silanized and native invertase. Thus, this procedure optimized the microenvironment of immobilized invertase suitable for the enzymatic synthesis of methyl fructoside.

• Bulletin of the Korean Chemical Society
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• 제16권11호
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• pp.1037-1042
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• 1995

The reaction of acetophenone 1-ureidoethylidenehydrazones 6 with a mixture of triphenylphosphine, carbon tetrachloride, and triethylamine in dichloromethane provides a general route to 1-(1-phenylethenyl)-5-(N-substituted amino)-1,2,4-triazoles 11 via the electrocyclization of the expected azino carbodiimide intermediates 9 to give the resonance stabilized azomethine imine 10a followed by a proton abstraction from the methyl group by amide anion. However, the same reaction of benzaldehyde 1-ureidoethylidenehydrazones 5 was unsuccessful. Under the same conditions, the reactions of benzaldehyde 1-N-acylureidoethylidenehydrazones 7 or acetophenone 1-N-acylureidoethylidenehydrazones 8 afforded 4H-1,2,4-triazolo[1,5-c][1,3,5]oxadiazines 16 or 17 via the zwitterionic species 15, or a [4+2] intramolecular cycloaddition from the carbodiimide intermediates 14, respectively.

• Bulletin of the Korean Chemical Society
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• 제30권2호
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• pp.409-414
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• 2009

Novel binol aldehydes derivatized at 2' hydroxy position with both uryl and acetamide groups (2), and diuryl groups (3) have been synthesized. Both were designed for streospecific binding and chirality conversion of general dipeptides with support of multiple hydrogen bonding donor sites in the receptors. The receptors, 2 and 3, converted the chirality of N-terminal amino acids of peptides such as Ala-Gly, Met-Gly, Leu-Gly and His-Gly with stereoselectivity on D-form over L-form. The stereoselectivity ratios were in the range of 5-11, somewhat higher than those of the binol receptor with mono uryl group (1). The DFT calculation at the B3LYP/6-31G$^*$//MPWB1K/6-31G$^*$ level revealed that 3-D-Ala-Gly was 2.2 kcal/mol more stable than 3-L-Ala-Gly. The considerable steric hindrance between the methyl group of the alanine and the imine CH moiety of the receptor seems to be the main contributing factor for the thermodynamic preference.

• 폴리머
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• 제29권2호
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• pp.135-139
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• 2005

본 연구에서는 세포 독성을 감소시키고 in vivo에서 표적화를 향상시키기 위하여 methoxypoly(ethylene glycol) (mPEG) 및 folate가 도입된 poly(ethylene imine)(PEI)를 합성하였다. mPEG 말단에 카복실 그룹을 도입하여 EDC/NHS에 의해 활성화시킨 후 PEI의 아민기와의 반응으로 mPEG-PEI를 합성하였다. Folate의 카복실 그룹을 EDC/NHS으로 활성화시킨 후 mPEG-PEI의 아민기와의 반응으로 PEG-folate-graft-PEI를 합성하였다. 합성된 고분자의 화학적 구조는 $^1H-NMR$과 H-n을 이용하여 확인하였다. 합성된 고분자와 DNA가 정전기적 인력에 의해 완전한 복합체의 형성을 확인하기 위해 여러 가지 N/P charge 비율로 agarose gel 전기영동 및 형광을 측정하였고, 2 이상의 N/P charge 비율에서 완전한 복합체를 형성함을 확인하였다. 복합체의 크기는 광산란장치 및 AFM으로부터 $100\~300nm$임을 관찰하였다. 이러한 결과들로부터 합성된 양이온성 고분자와 DNA가 복합체를 잘 이루어지는 것을 관찰하였고 유전자 전달체로서의 가능성을 평가하고자 하였다.

• Bulletin of the Korean Chemical Society
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• 제34권7호
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• pp.1985-1989
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• 2013

A simple colorimetric and fluorescent anion sensor 1 based on salicylimine showed a high selectivity and sensitivity for detection of cyanide in aqueous solution. The receptor 1 showed high selectivity toward $CN^-$ ions in a 1:1 stoichiometric manner, which induces a fast color change from colorless to orange and a dramatic enhancement in fluorescence intensity selectively for cyanide anions over other anions. Such selectivity resulted from the nucleophilic addition of $CN^-$ to the carbon atom of an electron-deficient imine group. The sensitivity of the fluorescence-based assay (0.06 ${\mu}M$) is below the 1.9 ${\mu}M$ suggested by the World Health Organization (WHO) as the maximum allowable cyanide concentration in drinking water, capable of being a practical system for the monitoring of $CN^-$ concentrations in aqueous samples.

• Bulletin of the Korean Chemical Society
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• 제31권9호
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• pp.2656-2664
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• 2010

We have synthesized a series of push-pull porphyrins containing both donor and acceptor substituents at the mesopositions and have examined their spectral and biological properties. The push-pull porphyrins containing both strong donor $NH_2$ and acceptor $NO_2$ at meso-positions, in which donor group condensed with the ligand, (2,6-bis(4-methylpiperazine-1-yl-methyl)-4-formlyphenol (L) to form imine linkages with porphyrin. The Schiff base ligand 5-[4-(2,6-bis(4-methylpiperazine-1-yl-methyl)-4-iminomethylphenol)phenyl]-10,15,20-tris(4-nitrophenyl) porphyrin [$an_3$(TPP)L] can be synthesized from 2,6-bis(4-methylpiperazine-1-yl-methyl)-4-formylphenol (L) and 5-(4-aminophenyl)-10, 15,20-tris(4-nitrophenyl)porphyrin. The push-pull porphyrin [$an_3$(TPP)L] was metallated to get copper, nickel and zinc complexes. The spectral, electrochemical, antibacterial, antifungal and cytotoxicity properties of all the donor- acceptor push-pull porphyrins and their complexes were characterized and studied.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2018년도 춘계학술대회 논문집
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• pp.80-80
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• 2018

실리콘 관통전극 (Through Silicon Via, TSV)는 메모리 칩을 적층하여 고밀도의 집적회로를 구현하는 기술로, 기존의 와이어 본딩 (Wire bonding) 기술보다 낮은 소비전력과 빠른 속도가 특징인 3차원 집적기술 중 하나이다. TSV는 일반적으로 도금 공정을 통하여 충전되는데, 고종횡비의 TSV에 결함 없이 구리를 충전하기 위해서 3종의 유기첨가제(억제제, 가속제, 평탄제)가 도금액에 첨가되어야 한다. 이러한 첨가제 중 결함 발생유무에 가장 큰 영향을 주는 첨가제는 평탄제이기 때문에, 본 연구에서는 이미다졸(imidazole) 계열, 이민(imine) 계열, 디아조늄(diazonium) 계열 및 피롤리돈(pyrrolidone) 계열과 같은 평탄제(leveler)의 작용기에 따라 TSV 충전 성능을 조사하였다. TSV 충전 시 관능기의 거동을 규명하기 위해 QCM (quartz crystal microbalance) 및 EQCM (electrochemical QCM)을 사용하여 흡착 정도를 측정하였다. 실험 결과, 디아조늄 계열의 평탄제는 TSV를 결함 없이 충전하였지만 다른 작용기를 갖는 평탄제는 TSV 내 결함이 발생하였다. QCM 분석에서 디아조늄 계열의 평탄제는 낮은 흡착률을 보이지만 EQCM 분석에서는 높은 흡착률을 나타내었다. 즉, 디아조늄 계열의 평탄제는 전기 도금 동안 전류밀도가 집중되는 TSV의 상부 모서리에서 국부적인 흡착을 선호하며 이로 인하여 무결함 충전이 달성된다고 추론할 수 있다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권6호
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• pp.465-470
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• 2004

Optimal conditions for the in situ immobilization of lipase in aldehyde-silica packed columns, via reductive amination, were investigated. A reactant mixture, containing lipase and sodium borohydride (NaCBH), was recirculated through an aldehyde-silica packed column, such that the covalent bonding of the lipase, via amination between the amine group of the enzyme and the aldehyde terminal of the silica, and the reduction of the resulting imine group by NaCBH, could occur inside the bed, in situ. Mobile phase conditions in the ranges of pH $7.0{\~}7.8$, temperatures between $22{\~}28^{circ}C$ and flow rates from $0.8{\~}1.5\;BV/min$ were found to be optimal for the in situ immobilization, which routinely resulted in an immobilization of more than 70 mg­lipase/g-silica. Also, the optimal ratio and concentration for feed reactants in the in situ immobilization: mass ratio [NaCBH]/[lipase] of 0.3, at NaCBH and lipase concentrations of 0.75 and 2.5 g/L, respectively, were found to display the best immobilization characteristics for concentrations of up to 80 mg-lipase/g-silica, which was more than a 2-fold increase in immobilization compared to that obtained by batch immobilization. For tributyrin hydrolysis, the in situ immobilized lipase displayed lower activity per unit mass of enzyme than the batch-immobilized or free lipase, while allowing more than a $45\%$ increase in lipase activity per unit mass of silica compared to batch immobilization, because the quantity of the immobilization on silica was aug­mented by the in situ immobilization methodology used in this study.