• Bulletin of the Korean Chemical Society
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• 제33권9호
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• pp.3009-3016
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• 2012

This study evaluated the use of iron-impregnated SBA-15 (Fe/SBA-15) as a catalyst for the oxidative degradation of persistent phenol analogues, such as 2-chlorophenol (2-CP), 4-chlorophenol (4-CP), 2-nitrophenol (2-NP), 4-nitrophenol (4-NP) and 2,4,6-trichlorophenol (2,4,6-TCP) in water. The oxidation reactions were carried out with reaction time, concentration of the phenols, amount of the catalysts, reaction temperature, pH of the reaction mixture as the process variables with or without using hydrogen peroxide as the oxidizing agent. The conversion achieved with Fe/SBA-15 at 353 K for 2-CP, 4-CP, 2-NP, 4-NP, 2,4,6-TCP was 80.2, 71.2, 53.1, 62.8, 77.3% in 5h with a reactant to $H_2O_2$ mole ratio of 1:1, and 85.7, 65.8, 61.9, 63.7, 78.1% in the absence of $H_2O_2$, respectively. The reactions followed pseudo first order kinetics. The leachability study indicated that the catalyst released very little iron into water and therefore, the possibility of secondary pollution is negligible.

• Advances in environmental research
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• 제4권1호
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• pp.39-48
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• 2015

Bisphenol A is widely used in plastic and other industrial consumer products. Release of bisphenol A and its analogues into the aquatic environment during manufacture, use and disposal has been a great scientific and public concern due to their toxicity and endocrine disrupting effects on aquatic wildlife and even human beings. More recent studies have shown that these alkylphenols may affect the molting processes and survival of crustacean species such as American lobster, crab and shrimp. In this study, we have developed gas chromatography with flame ionization detection (GC-FID) and gas chromatography-mass spectrometric (GC-MS) methods for the determination of bisphenol A and its analogues in shrimp Macrobrachium rosenbergii, blue crab Callinectes sapidus and American lobster Homarus americanus samples. Bisphenol A, 2,4-bis-(dimethylbenzyl)phenol and 4-cumylphenol were found in shrimp in the concentration ranges of 0.67-5.51, 0.36-1.61, and < LOD (the limit of detection)-1.96 ng/g (wet weight), and in crab of 0.10-0.44, 0.13-0.62, and 0.26-0.58 ng/g (wet weight), respectively. In lobster tissue samples, bisphenol A, 2-t-butyl-4-(dimethylbenzyl)phenol, 2,6-bis-(t-butyl)-4-(dimethylbenzyl)phenol, 2,4-bis-(dimethybenzyl)phenol, 2,4-bis-(dimethylbenzyl)-6-t-butylphenol and 4-cumylphenol were determined at the concentration ranges of 4.48-7.01, 1.23-2.63, 2.71-9.10, 0.35-0.91, 0.64-3.25, and 0.44-1.00 ng/g (wet weight), respectively. At these concentration levels, BPA and its analogs may interfere the reproduction and development of crustaceans, such as larval survival, molting, metamorphosis and shell hardening.

• 약학회지
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• 제52권1호
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• pp.85-91
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• 2008

8-Acyl and 8-sulfonylamidowogonin analogues were synthesized as potential anti-inflammatory agents. Nitration of 5,7-dihydroxyflavone (chrysin) followed by methylation of phenol groups and reduction of nitro group yielded 8-aminowogonin analogues. Acylation and sufonylation of 8-aminowogonin followed by demethylation reactions gave the title compunds. The synthesized wogonin analogues showed much reduced inhibitory activity on prostaglandin $E_2\;(PGE_2)$ production.

• 식물조직배양학회지
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• 제28권3호
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• pp.165-171
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• 2001

Adenosine deaminase 유전자를 연초의 형질전환용 표지유전자로 활용할 때 형질전환체 여부를 매우 빠르고 눈으로 직접 색깔을 확인할 수 있는 새로운 방법이 개발되었다. ADA 효소는 독성인 adenosine 유도체를 비독성인 inosine 유도체와 암모니아로 변환시키는데, 이때 형성된 암모니아를 phenol-nitoprusside와 alkaline-hypochlorite 용액을 이용하여 청색으로 변환시켜 96 well plate상에서 1시간 내에 형질전환체 여부를 쉽게 확인할 수 있게 되었다. ADA효소의 substrate로서 9-D-arabinofuranosyl adenine, cordycepin, 2'-deoxyadenosine, adenosine and xylofuranosyl adenine이 모두 가능하였으며, substrate 용액의 최적조건은 adenosine 10 mM과 pH 7.5이었다. 특히 형질전환체는 ADA효소의 inhibitor인 deoxycoformycin이 함유되어 있는 용액 속에서는 adenosine을 inosine과 암모니아로 변환시키지 못해 색깔의 변화가 없었는데, 이는 형질전환체에서 색깔의 변화는 ADA효소의 작용 때문에 일어나는 것을 의미한다. 따라서 본 연구결과는 ADA 표지유전자가 도입된 형질전환체의 확인에 있어서 GUS gene system과 같이 눈으로 직접 확인할 수 있을 뿐만 아니라 매우 작은 크기의 형질전환체 절편으로 쉽고, 빠르면, 값싸게 확인할 수 있게 되었다.

• 대한화장품학회지
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• 제35권4호
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• pp.271-276
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• 2009

기질 화합물로써 일련의 4-($R_1$)-benzyl alcohol 및 4-($R_2$)-phenol 유도체들의 치환기($R_1$ 및 $R_2$)가 변화함에 따른 tyrosinase 활성저해에 관한 3차원적인 구조-활성 상관 (3D-QSARs) 모델을 유도하고 정량적으로 검토하였다. 그 결과, 입체장, 정전기장, 소수성장 및 수소결합 주게장의 조합조건에서 통계적으로 양호한 CoMSIA 2 모델(상관성; $r^2\;=\;0.858$ 및 예측성; $q^2\;=\;0.951$)을 유도하였다. 등고도 분석결과, 기질분자의 $R_2$-치환기는 입체적으로 작고 음전하를 띄며, 소수성이면서 수소결합 주게장을 선호하지 않는 치환기가, 그리고 $R_1$-치환기는 양전하를 띄며 수소결합 주게장을 선호하는 치환기가 tyrosinase의 저해활성이 증가 될 것으로 예상되었으며, 수소결합 받게장은 전혀 영향을 미치지 않았다.

• Bulletin of the Korean Chemical Society
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• 제21권9호
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• pp.891-895
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• 2000

Transmission of substituent effects through 5-membered heteroaromaticrings isinvestigated theoretically at the RHF/6-31+G* and B3LYP/6-31+G* levelsusing the deprotonation equilibria of phenol analogues with heteroatoms Y = NH, O, PHand S. The incr ease in the resonance delocalization of the $\pilone-pair$ on the phe-nolic oxygen atom, $n\pi(O)$, accompanied with the deprotonation depends on the heteroatom Y,in the order NH < O < PH < S. This represents the $\pielectron$ accepting ability, or conversely reverse order of the $\pielectron$ donating ability of the $\pilone-pair$ on Y, $n\pi(Y).$ The transmission efficiency of substituenteffects is, however,in the reverse order NH > O > S, which represents the order of delocalizability of $n\pi(Y).$ A better correlation is obtained with ${\sigma}p$ - than with ${\sigma}p$ for the Hammett type plots with the positive slope, $\rho-$ > 0, of the magnitude in the same order as that for the delocalizability of $n\pi(Y).$ Thedeprotonation energy, ΔG = [G(PA) + G(H+)] -G(P), decreases with the increasein the extence delocalization in the order NH > O > PH > S.

• Bulletin of the Korean Chemical Society
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• 제23권4호
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• pp.599-603
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• 2002

A selective enzyme-linked immunosorbent assay (ELISA) for the insecticide isofenphos was developed. Three different analogues (haptens) of isofenphos were synthesized and were coupled to carrier proteins through the pesticide thiophosphate group t o use as immunogens or coating antigens. Rabbits were immunized with one of the haptens coupled to BSA for production of polyclonal antibodies and the sera were screened against each of the other two haptens coupled to ovalbumin (OVA). Using the sera of highest specificity, an antigen-coated ELISA was developed, which showed an I50 of 96 ng/mL with the detection limit of 2 ng/mL. The antibodies showed negligible cross-reactivity with other organophosphorus pesticides and the phenol metabolite of isofenphos, which makes the developed assay suitable for the selective detection of isofenphos. An antibody-coated ELISA was also developed, which showed an I50 of 580 ng/mL with a detection limit of 70 ng/mL.