• Bulletin of the Korean Chemical Society
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• v.24 no.11
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• pp.1627-1631
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• 2003

Molecular modeling was performed to comprehend the chiral recognition of ${\alpha}$-methoxy-${\alpha}$-trifluoromethylphenylacetic acid (MTPA) enantiomers by cyclomaltoheptaose (${\beta}$-cyclodextrin,${\beta}$-CD) and 6-amino-6-deoxy-cyclomaltoheptaose (am-${\beta}$-CD). Monte Carlo (MC) docking coupled to constant temperature molecular dynamics (MD) simulations was applied to the investigation for the ${\alpha}$-methoxy-${\alpha}$-trifluoromethylphenylacetic acid complexation with two different CDs in terms of the relative distribution of the interaction energies. The calculated results are finely correlated with the experimental observations in chiral recognition thermodynamics. Am-${\beta}$-CD as a host showed the superior enantio-discrimination ability to the native ${\beta}$-CD where the amino group of am-${\beta}$-CD was critically involved in enhancing the ability of chiral discrimination via the Coulombic interaction with MTPA.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1703-1706
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• 2012

Rice blast is the most serious disease of rice due to its harmfulness and its world wide distribution. $Magnaporthe$ $grisea$ is the cause of rice blast disease and destroys rice enough to feed several tens of millions of people each year. Fungicides are commonly used to control rice blast. But $M.$ $grisea$ acquires resistance to chemical treatments by genetic mutations. 2-Phenylimino-1,3-thiazolines were proposed as a novel class of fungicides against $M.$ $grisea$ in the previous study. To develop compounds with a higher biological activity, a new series of 2-phenylimino-1,3-thiazolines was synthesized and its fungicidal activity was determined against $M.$ $grisea$. The QSAR analysis was carried out on a series of 2-phenylimino-1,3-thiazolines. The QSAR results showed the dependence of fungicidal activity on the structural and physicochemical features of 2-phenylimino-1,3-thiazolines. Our results could be used as guidelines for the study of the mode of action and further design of optimal fungicides.

• Bulletin of the Korean Chemical Society
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• v.35 no.11
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• pp.3280-3288
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• 2014

Alkoxyalcohols are used as solvents or preservatives in various consumer products such as wet wipes. The metabolites of alkoxyalcohols are known to be chronically toxic and carcinogenic to animals. Thus, an analytical method is needed to monitor alkoxyalcohols in wet wipes. The aim of this study was to develop a simultaneous analytical method for 14 alkoxyalcohols using headspace gas chromatography coupled with mass spectrometry to analyze the wet wipes. This method was developed by comparing with various headspace extraction parameters. The linear calibration curves were obtained for the method ($r^2$ > 0.995). The limit of detection of alkoxyalcohols ranged from 2 to $200ng\;mL^{-1}$. The precision of the determinative method was less than 18.20% coefficient of variation both intra and inter days. The accuracy of the method ranged from 82.86% to 119.83%. (2-Methoxymethylethoxy)propanol, 2-phenoxyethanol, and 1-phenoxy-2-propanol were mainly detected in wet wipes.

• Bulletin of the Korean Chemical Society
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• v.19 no.10
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• pp.1032-1036
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• 1998

Intercalation compounds of organic anions into layered double hydroxides (LDH) are synthesized by the coprecipitation route. X-ray diffraction data reveal that the intercalated terephthalate (TP), naphthalene-2,6-disulfonate (NA26), and anthraquinone-2,6-disulfonate (AQ26) are arranged with their molecular planes perpendicular to the hydroxide layer. HPLC data show that 26.2% of TP and 73.8% of AQ26 are cointercalated, whereas NA26 is not intercalated into the Zn/Al-LDH. These results indicate the possibility of a molecular recognition ability of Zn/Al-LDH. The molecular recognition ability of intercalation into Zn/Al-LDH is in the order AQ26 > TP >> NA26.

• Bulletin of the Korean Chemical Society
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• v.28 no.5
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• pp.805-810
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• 2007

Molecular recognition for a specific cation depending on the change of the oxidation state of the metal catalyst component contained in the hydrogel network has been studied in a self-oscillating hydrogel. The selfoscillating hydrogels are synthesized by the copolymerization of N-isopropylacrylamide (NIPAAm), lead methacrylic acid (Pb(MAA)2), and Ru(bpy)3 2+ monomer as a metal catalyst component. The recognition for a specific cation (in this study, Ca2+ has been used) is characterized by the adsorbed amount of Ca2+ into the gel. The recognition of the gels for Ca2+ is higher at the temperature below the LCST, and also higher at the oxidized state than at reduced state of the metal catalyst component which corresponds to a more swollen state. Moreover, a propagating wave induced by a periodic change of the oxidation state with the diffusion phenomena in the oscillating hydrogel shows a possibility for temporal and site-specific molecular recognition due to the local swelling of the gel.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.263.2-263.2
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• 2013

We report a systematic investigation of a set of macrophotoinitiators for use in polymerization-based signal amplification. To test the dependence of photopolymerization responses on the number of photoinitiators localized per molecular recognition event, we gradually increased the number of photoinitiator molecules coupled to a scaffold macromolecule. Macrophotoinitiators constructed with an average of 7 to 168 photoinitiators per polymer with the goals of quantifying the relationship between the number of initiators per binding event and the degree of amplified colorimetric readout. To evaluate the capacity of the macrophotoinitiators to detect molecular recognition, neutravidin was coupled to these molecules to recognize biotin-labeled DNA immobilized on biochip test surfaces. Fluorescein macroinitiators are found to be useful in detecting molecular recognition above a threshold of initiators per polymer. Above this threshold, increasing the number of initiators per macroinitiator resulted in increased signal strength.

• Prospectives of Industrial Chemistry
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• v.23 no.3
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• pp.42-55
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• 2020

다양한 분석물을 탐지하기 위해 타겟 특이적이며 높은 안정성과 효율을 지닌 화학센서 개발은 화학자들의 숙원이다. 그들의 노력으로 지난 수십 년간 많은 센서들이 개발되었으며 화학, 생물학, 약물학, 생리학, 환경 화학 등 여러 분야에서 응용이 되고 있다. 본고에서는 화학센서 개발의 디자인 원리와 발광 메커니즘(ICT, FRET, PeT, AIE)에 대해 알아보고 최근 개발된 유기·무기분자 기반 탐침과 나노물질 및 고분자를 이용한 센서 동향에 대해 다루고자 한다. 나아가 여전히 존재하는 개발 과제는 어떠한 것들이 있는지 짚어보고, 앞으로 화학센서 개발이 나아갈 방향에 대해 예상해보고자 한다.

• Bulletin of the Korean Chemical Society
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• v.18 no.7
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• pp.681-684
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• 1997

• BMB Reports
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• v.34 no.6
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• pp.489-495
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• 2001

DNA damage by UV and environmental agents are the major cause of genomic instability that needs to be repaired, otherwise it give rise to cancer. Accordingly, mammalian cells operate several DNA repair pathways that are not only responsible for identifying various types of DNA damage but also involved in removing DNA damage. In mammals, nucleotide excision repair (NER) machinery is responsible for most, if not all, of the bulky adducts caused by UV and chemical agents. Although most of the proteins involved in NER pathway have been identified, only recently have we begun to gain some insight into the mechanism by which proteins recognize damaged DNA. Binding of Xeroderma pigmentosum group C protein (XPC)-hHR23B complex to damaged DNA is the initial damage recognition step in NER, which leads to the recruitment of XPA and RPA to form a damage recognition complex. Formation of damage recognition complex not only stabilizes low affinity binding of XPA to the damaged DNA, but also induces structural distortion, both of which are likely necessary for the recruitment of TFIIH and two structure-specific endonucleases for dual incision.

• Bulletin of the Korean Chemical Society
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• v.30 no.6
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• pp.1247-1251
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• 2009

The recognition of neutral aromatic substrates by different neutral calix[4]arene receptors 1, 2, and 3 was studied by NMR spectroscopy. The stoichiometry is 1:1 in all cases as was confirmed by jobs plot. Owing to the deep cavity, 1 affords stronger binding abilities for substrate 4 and 5, while all receptors remained inert for substrates 6 and 7. The binding constants determined by $^1H$ NMR titration show that the recognition of substrate 4 by 1 gives strongest complexation ($K_a\;of\;9.8\;{\times}\;102\;M^{-1}$).