• 한국수산과학회지
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• 제40권5호
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• pp.282-287
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• 2007

Chloroanilines are aromatic amines used as intermediate products in the synthesis of herbicides, azo-dyes, and pharmaceuticals. 3,4-dichloroaniline (DCA) is the degradation product of some herbicides (diuron, propanil, and linuron) and of trichlorocarbanilide, a chemical used as an active agent in the cosmetic industry. The compound, however, is considered a potential pollutant due to its toxicity and recalcitrant property to humans and other species. With the increasing necessity for bioremediation, we sought to isolate bacteria that degraded 3,4-DCA. A bacterium capable of growth on 3,4-DCA as the sole carbon source was isolated from seaside sediment using a dilution method with a culture enriched in 3,4-DCA. The isolated strain, YM-7 was identified to be Pseudomonas sp. The isolated strain was also able to degrade other chloroaniline compounds. The isolated strain showed a high level of catechol 2,3-dioxygenase activity on exposure to 3,4-DCA, suggesting that this enzyme is an important factor in 3,4-DCA degradation. The activity toward 4-methylcatechol was 53.1% that of catechol, while the activity toward 3-methylcatechol, 4-chlorocatechol and 4,5-chlorocatechol was 18.1, 33.1, and 6.9%, respectively.

• 대한화학회지
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• 제37권1호
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• pp.136-140
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• 1993

새로운 methotrexate 중간체인 diethyl N-[4-{[(2,4-diamino-6-yl)methyl]-amino}benzoyl]-L-glutamate(10)를 합성하기 위하여 p-nitrobenzoic acid를 chlorination한 다음 L-glutamic acid와 coupling하고 이를 esterification한 후, 환원과 methylation시켜 diethyl N-(4-methylaminobenzoyl)-L-glutamate(7)를 합성하였다. 이 화합물(7)을 DMF 존재하에서 NaH와 allyl chloride를 가하여 allylation한 다음 여기에 $IN_3$ addition 반응으로 diethyl-p-[N-(2-azido-3-iodopropyl)-N-methyl]aminobenzoyl-L-glutamate(9)를 합성하였다. 이 화합물(9)을 2,4,5,6-tetraaminopyrimidine hydrochloride와 cyclization시켜 methotrexate diethylester를 얻었다.

• Animal cells and systems
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• 제6권4호
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• pp.305-309
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• 2002

Actinorhodin antibiotics produced by Streptomyces lividans TK24 are blue pigments with a weak antibiotic activity, derived from one acetyl-CoA and 15 malonyl-CoA units via a typical ployketide pathway. In an attempt to clone polyketide biosynthetic genes of S. lividans TK24, hybridizing fragments in the genomic DNA of S. lividans TK24 were detected by use of acn and act III polyketide synthase gene probes. Since typical aromatic polyketide bio-synthetic gene clusters are roughly 22-34 Kb long, we constructed in E. coli XL-Blue MR using the Streptomyces-E. coli bifunctional shuttle cosmid vector (pojn46). Then, about 5,000 individual E. coii colonies were thor-oughly screened with acrl-ORFI and actIII probes. From these cosmid libra-ries, 12 positive clones were identified. Restriction analysis and southern hybridization showed two polyketide biosynthetic gene clusters in this organism. These cosmid clones can be transformed into Streptomyces parvulus 12434 for expression test that identify product of actinorhodin biosynthetic genes by heterologous expression. Thus, heterologous expres-sion of a derivative compound of a actinorhodin biosynthetic intermediate was obtained in pKE2430. Expression of these compounds by the trans-formants was detected by photodiode array HPLC analysis of crude extracts.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권6호
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• pp.553-556
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• 2006

A cis-1,2-dichloroethylene (cis-DCE)-degrading anaerobic bacterium, Clostridium sp. strain KYT-1, was isolated from a sediment sample collected from a landfill site in Nanji-do, Seoul, Korea. The KYT-1 strain is a gram-positive, endospore-forming, motile, rod-shaped anaerobic bacterium, of approximately $2.5{\sim}3.0\;{\mu}m$ in length. The degradation of cis-DCE is closely related with the growth of the KYT-1 strain, and it was stopped when the growth of the KYT-1 strain became constant. Although the pathway of cis-DCE degradation by strain KYT-1 remains to be further elucidated, no accumulation of the harmful intermediate, vinyl chloride (VC), was observed during anaerobic cis-DCE degradation. Strain KYT-1 proved able to degrade a variety of volatile organic compounds, including VC, isomers of DCE (1,1-dichloroethylene, trans-1,2-dichloroethylene, and cis-DCE), trichloroethylene, tetrachloroethylene, 1,2-dichloroethane, 1,1,1-trichloroethane, and 1,1,2-trichloroethane. Strain KYT-1 degraded cis-DCE at a range of temperatures from $15\;to\;37^{\circ}C$, with an optimum at $30^{\circ}C$, and at a pH range of 5.5 to 8.5, with an optimum at 7.0.

• Tribology and Lubricants
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• 제25권1호
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• pp.7-12
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• 2009

Coating brittle intermetallic compounds on metal can enlarge the range of their use. It is found that intermetallic compound coating layers made by only combustion synthesis in an electric furnace have porous multi-phase structures containing several intermediate phases, even though the coating layers show good wear resistance. In this study, dense $Ni_{3}Al$ single phase layer corresponding to the initial composition of the mixed powder is coated on two different ferrous materials by the diffusing treatment after combustion synthesis. After- ward, sliding wear behaviors of the coating layer are evaluated in comparison with that of the coating layer with porous multi-phase structure made by only combustion synthesis. As a result, the wear properties of the coating layer composed of dense $Ni_{3}Al$ single phase are considerably improved at the range of low sliding speed com- pared with that of the coating layer with porous multi-phase structure, particularly in the running-in wear region. This is attributed to the fact that wear of the coating layer is progressed by shearing as a sequence of adhesion, not by occurring of pitting on the worn surface due to having dense structure without pores.

• 상하수도학회지
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• 제35권1호
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• pp.27-37
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• 2021

Tetracycline is one of the most commonly used as antibiotics for the livestock industry and it is still widely used nowadays. Tetracycline and its metabolites are excreted with excrement, which is difficult to completely removed with conventional sewage treatment, therefore it is apprehended that the tetracycline-resistant bacteria occurs. In this study, the oxidant named ferrate(VI) was used to degrade the tetracycline and investigate the reaction between ferrate(VI) and tetracycline under various aqueous conditions. The highest degradation efficiency of tetracycline occurred in basic condition (pH 10.1 ± 0.1) because of the pKa values of tetracycline and ferrate(VI). The results also showed the effect of water temperature on the degradation of tetracycline was not significant. In addition, the dosage of ferrate(VI) was higher, the degradation of tetracycline and the self-degradation of ferrate(VI) also higher, finally the efficiency of ferrate(VI) was lower. The results said that the various mechanisms effects the reaction of ferrate(VI) oxidation, it required the consideration of the characteristics of the target compound for optimal degradation efficiency. Additionally, intermediate products were detected with LC/MS/MS and three degradation pathways were proposed.

• Bulletin of the Korean Chemical Society
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• 제10권4호
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• pp.360-362
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• 1989

Catalytic isomerization of unsaturated alcohols to the corresponding carbonyl compounds with$Rh(ClO_4)(CO)(PPh_3)_2\;(1)\;and\;[Rh(CO)(PPh_3)_3]ClO_4$ (2) is faster under hydrogen (where hydrogenation also occurs to give saturated alcohols) than under nitrogen. The isomerization under hydrogen seems to occur through an alkylhydridorhodium(III) complex which also undergoes reductive elimination to give hydrogenation products, saturated alcohols. The isomerization under hydrogen is faster with 2 than with 1, which is understood by acceleration of the last step, enol formation by $PPh_3$ dissociated from 2 and present in the reaction mixture when 2 is used as catalyst. Relative rates of the isomerization observed for different unsaturated alcohols are interpreted by steric effects of substituted groups and numbers of hydrogens to be abstracted by the rhodium of the intermediate, alkylhydridorhodium(III) to undergo the reductive elimination to give enol which is then rapidly converted into a carbonyl compound. It has been observed that the hydrogenation is relatively significant when reactions occur slowly whereas the isomerization is predominant when reactions proceed rapidly.

• 한국패션뷰티학회지
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• 제4권4호
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• pp.7-15
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• 2006

Japan's modern fashion, which already became distinguished in the world fashion market, creates originality by identifying its own color as well as shape and details from its tradition. The purpose of this study was to draw the results of examining the perceived meanings of color revealed in the culture, arts and clothing color of Heian period in Japan and searching them in contemporary Japanese fashion. The scope of study was the perceived meaning of color in Heian period and Japanese contemporary fashion. In the methodologies, the literature and the empirical study focused on Heian's culture, including art history, ethnology, and the history of clothing and the contemporary fashion collection. Japan's original middle colors and intermediate colors began to be created in Heian period. The color aesthetic characteristics of Heian period appeared the beauty of compound color, layered color, overlapped color in Japanese contemporary fashion.

• 대한화학회지
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• 제19권3호
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• pp.174-178
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• 1975

4-(${\beta}$-Guanidinoethyl)-17${\alpha}$-methyl-4-aza-5${\alpha}$-androstan-17${\beta}$-ol(V)을 합성하는데에 필요한 중간화합물인 17${\alpha}$-methyl-4-aza-5${\alpha}$-androstan-17${\beta}$-ol(IX)은 4단계를 거쳐 합성하였으며 IX을 chloroacetonitrile과 축합반응을 한후 $LiAlH_4$로서 환원하여 4-(${\beta}$-aminoethyl)-17${\alpha}$-methyl-4-aza-5${\alpha}$-androstan-17${\beta}$-ol(XI)을 얻었다. Tktle compound인 V은 3가지의 시약, 2-methyl-2-thiopseudourea,3,5-dimethylpyrazole-1-carboxamidine, cyanamide를 각각 XI와 반응시켜 좋은 수득률을 얻었다. 약리작용의 실험결과 V은 classical한 adrenergic neurone blocking agents와 유사하며 혈압강하제로서의 전망은 좋다고 예상된다.

• 공업화학
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• 제10권7호
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• pp.985-989
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• 1999

유기 실란화합물을 사용하여 실리카($SiO_2$)박막을 감압 유기금속 화학증착법(LPMOCVD)으로 제조하였다. 원료로는 triethyl orthosilicate(TRIES)를 사용하였다. 실험조건은 반응기의 출구압력을 1~100 torr, 반응온도는 $600{\sim}900^{\circ}C$로 하였다. 높은 반응온도와 원료농도에서는 $SiO_2$가 빠른 성장속도를 나타내었다. 마이크로 스케일 트랜치에서 층덮임이 좋게 나타났는데, 이것은 응축된 다량체들이 트랜치쪽으로 유동하는 현상 때문으로 생각되었다. 원료가스가 중합반응을 하여 다량체(2량체, 3량체, 4량체 등)들이 생성되고, 그 다량체들이 확산하여 고체표면에서 응축되는 반응경로를 따를 것으로 추정된다. 반응관의 출구에서 기상중의 화학종들을 사극질량분석기로 분석한 결과, 반응온도 $650{\sim}700^{\circ}C$에서는 단량체, 원료가스의 2량체, 고분자들의 피크가 관측되었다. 고온($900^{\circ}C$)에서는 거의 모든 원료가스와 중간체(중합된 다량체) 분자들이 산화되었거나 차가운 관벽에 응축되어 고분자들의 피크가 없어졌다.