• Bulletin of the Korean Chemical Society
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• v.32 no.1
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• pp.273-276
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• 2011

Uniform Ag nanoparticles (< 10 nm) were effectively prepared in 1-amino-4-methylpiperazine as a solvent with multiple functions including reduction and stabilization. An Ag-complex such as $Ag_2(ehac)_2(eha)_2$ (ehac = 2-ethylhexylammonium carbamate; eha = 2-ethylhexylamine) was used as an Ag-precursor, whereas the usage of a salt such as $AgNO_3$ showed the formation of Ag nanoparticles in larger and irregular size (30 - 500 nm). The Ag nanoparticles (< 10 nm) prepared by using the Ag-complex could also be effectively stabilized by 1-amino-4-methylpiperazine. Transmission electron micrographs confirmed that the Ag particles were spherical and in the nanometer size.

• Bulletin of the Korean Chemical Society
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• v.31 no.9
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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.

• Bulletin of the Korean Chemical Society
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• v.35 no.8
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• pp.2251-2256
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• 2014

We have successfully decorated reduced graphene oxide (RGO) with silver nanoparticles (AgNPs) by microwaving silver alkylcarbamate for 13 seconds using 1-amino-4-methylpiperazine. Uniform AgNPs (20-40 nm) were effectively prepared, and 1-amino-4-methylpiperazine acted as a reaction medium, reducing agent, and stabilizer. Particle size and morphology were correlated with the silver alkylcarbamate concentration and microwave time. The graphene/AgNPs composites were characterized by Raman, X-ray diffraction, and scanning electron microscopy to confirm that the AgNPs were uniformly decorated onto the graphene. Measurements of the transparent conductive property at room temperature indicated that these graphene/AgNPs nanosheets with 55.45% transmittance were electrically continuous with a sheet resistance of approximately $43{\Omega}/{\Box}$.

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2004.05a
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• pp.49-68
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• 2004

New analogues of Sildenafil (Viagra${\circledR}$)were identified in the imported Chinese herb drinks, which have been added illegally for affecting penile erectile dysfunction. In order to elucidate the chemical structures of Sildenafil analogues, separation and purification were carried out and followed by analysis of the routine 1D and 2D NMR spectroscopy and FAB mass spectrometry. Based on analytical data one compound was maned as Homosildenafil contains ethylpiperazine switched with methylpiperazine of Sildenafil and the other one was called an Hongdenafil contains ethylpiperazine switched with methylpiperazine and acetyl group instead of sulfonyl group of Sildenafil. As results, Homosildenafil and Hongdenafil were put on the list as new inspection items of the imported food for protectiong public health in Korea.

• YAKHAK HOEJI
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• v.35 no.3
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• pp.190-196
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• 1991

N-monoalkyiations of ditertiary diamines succeed best in nitromethane or ethanol at low temperature, unsymmetrical piperazine and piperidine compounds react selectively under these condition at the sterically less hindered nitrogen atom.

• Bulletin of the Korean Chemical Society
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• v.33 no.2
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• pp.483-488
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• 2012

We successfully decorated multi-wall carbon nanotubes (MWNTs) with silver by reacting Ag-NPs with thiolfunctionalized MWNT-SH. Ag alkylcarbamate complex was used as an Ag precursor. Uniform Ag-NPs (5-10 nm) were effectively prepared by microwaving within 60 s using 1-amino-4-methylpiperazine (AMP), which acts as a reaction medium, reducing agent, and stabilizer. The MWNTs were functionalized with 2-aminoethanethiol. Exploiting the chemical affinity between thiol and Ag-NPs, Ag-MWNT nanohybrids were obtained by spontaneous chemical adsorption of MWNT-SH to Ag through Ag-S bonds. The Ag-S-MWNTs were characterized by TGA, XRD, and TEM to confirm that Ag-NPs were uniformly decorated onto the MWNTs. The Ag-S-MWNTs were then employed as conducting filler in epoxy resin to fabricate electrically conducting polymer composites. The electrical properties of the composites were measured and compared with that containing MWNT-SH. The electrical conductivity of composites containing 0.4 wt % Ag-S-MWNT was four orders of magnitude higher than those containing same content of MWNT-SH, confirming Ag-S-MWNT as an effective conducting filler.

• YAKHAK HOEJI
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• v.34 no.4
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• pp.244-251
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• 1990

N-Monoalkylations of ditertiary diamines succeed best in nitromethane or ethanol at low temperature. Unsymmetrical 1,2-diaminoethane, 1,3-diaminopropane and piperazine compounds react selectively under these conditions at the sterically less hindered nitrogen atom.

• Journal of the Korean Chemical Society
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• v.63 no.1
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• pp.7-11
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• 2019

Olmutinib, N-[3-({2-[4-(4-methylpiperazine-1-yl)aniline]thieno[3,2-d]Pyrimidin-4-yl}oxy)phenyl]prop-2-enamide dihydrochloride monohydrate, $Olita^{TM}$ is an oral, third-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI) that was developed by Boehringer Ingelheim and Hanmi Pharmaceutical Co. Ltd for the treatment of non-small cell lung cancer (NSCLC). The aim of this work was to investigate the existence of polymorphs and pseudopolymorphs of olmutinib. Three crystal forms of olmutinib have been isolated by recrystallization and characterized by differential scanning calorimetry (DSC), thermogravimetric (TG) analysis and powder X-ray diffractometry (PXRD). From the DSC and TG data it was confirmed that Form 1 is monohydrate, Form 2 is dihydrate, Form 3 is 1.5 hydrate. The PXRD patterns of three crystal forms were different respectively. After storage of 1 month at $2^{\circ}C$, 24% RH (Relative Humidity), Form 1, Form 2, and Form 3 were not transformed.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.212-212
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• 1994

본 연구소에서 분리하여 항암활성을 측정한바 있는 Sesquiterpene lactone계열의 KR-53170이 in vitro에 비해 in vivo에서 상대적으로 낮은 효력을 보이는데 착안 그 유도체들을 합성함으로써 in vivo stability 및 efficacy를 개선하고자 하였다. 합성된 물질의 in vivo activity는 human tumor cell중에서 A549(폐암), SK-OV-3(난소암1, SK-MEL-2(피부암), XF-498(중추신경계암), HCT-15(직장암)의 5개 암세포를 이용하여 ED$_{50}$($\mu\textrm{g}$/ml )를 측정하였으며 대조물질로는 KR-53170과 Cisplatin이 사용되었다. 그 결과 HR-53170의 terminal methyl ketone이 carboxylic acid로 변환된 CW-251001과 이것의 methyl ester인 CW-251002, ethyl ester인 CW-251003, 그리고 morpheline과 수용성으로 N-methylpiperazine, N-methyl-N'-aminopiperazine, 4-Piperidinopiperidine을 결합시켜서 합성한 CW-251011, CW-251012, CW-251013, CW-251014가 in vitro에서 어느 정도 활성을 유지하였다. 특히 이들중 CW-251001, CW-251012, CW-251013, CW-2s1014는 물에 대한 용해도가 상당히 개선되어 in vivo 활성검색을 위한 후보물질로 고려되었다. 하지만 이들중 CW-251001은 in vivo에서 낮은 농도에서는 활성이 거의 없었으며 놓은 농도에서는 독성을 나타내었다.

• Korean Chemical Engineering Research
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• v.50 no.2
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• pp.348-352
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• 2012

Amine volatility occurring on the $CO_2$ capture process may result in significant economic losses and environmental impact. In this study, using an volatility measurement apparatus, we measured a amine volatility of various amines including MEA(Monoethanolamine), MDEA(N-Methyldiethanolamine), Pz(Piperazine), AMP(2-Amino-2-methyl-1-propanol), 2-MP(2-Methylpiperazine), DGA(Diglycolamine). For the quantitative analysis of volatility, we analyzed the effects of temperature and $CO_2$ loading using an gas chromatography analysis. The result shows that the amine volatility was increased by increasing Henry's constant(MDEA$-CH_3$)(for AMP).