• 대한의생명과학회지
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• 제11권4호
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• pp.509-515
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• 2005

This study was conducted to determine the kinetics of cyclohexane metabolites (the biomarker on cyclohexane exposure), the changes of hepatic cyclohexane metabolizing enzyme activities and the metabolites of cyclohexane in urine or serum. The rats were sacrificed at 2, 4, 8, 12 and 24 hr after administration of one dose of cyclohexane (1.56 g/kg body weight, i.p.). The metabolites of cyclohexane in urine were identified as cyclohexanol, cyclohexanone, trans-l,2-cyclohexanediol and 1,4-cyclohexanediol with cyclohexane metabolite being 124.00, 0.78, 23.28 and 2.75 (g/g of creatinine, $1\times10^{-3}$). Most of the cyclohexanol and trans-l,2-cyclohexanediol were determined to be in the form of $\beta-glucuronide$ conjugates, whereas cyclohexanone and 1 ,4-cyclohexanediol were found as free forms. In toxicokinetics of serum cyclohexane metabolites, cyclohexanol showed a rapid increase, reaching the plateau at 4 hr, after this time rapidly decreased throughout 24 hr. Changes of cyclohexanone also showed the similar pattern with cyclohexanol except somewhat lower concentration. Trans-l,2-cyclohexanediol, however, showed a gradual increase until 12 hr with the continued same levels throughout 24 hr. On the other hand, 1,4-cyclohexanediol was detected as trace levels at 4 and 12 hr, respectively. The administration of cyclohexane led to a significant increase of hepatic aniline hydroxylase activity from 2 to 8 hr. The activity of hepatic alcohol dehydrogenase showed a significant increase at 4 hr and then were recovered to the level of the control at 24 hr. On the other hand, there were no differences in liver weightlbody weight between the control and cyclohexane-treated animals. However, there were the changes of aniline hydroxylase and alcohol dehydrogenase activities on time-dependent pattern after cyclohexane treatment, which influence on the degree of cyclohexane metabolites both in blood and urine. These results suggest that differential determination of cyclohexane metabolites in urine and serum may be able to be as a biomarker of cyclohexane-exposure in the body. But in this fields further study is needed.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권4호
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• pp.277-281
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• 2006

Spherical micro silica sol-gel immobilized enzyme beads were prepared in an emulsion system using cyclohexanone and Triton-X 114. The beads were used for the in situ immobilization of transaminase, trypsin, and lipase. Immobilization during the sol to gel phase transition was investigated to determine the effect of the emulsifying solvents, surfactants, and mixing process on the formation of spherical micro sol-gel enzyme beads and their catalytic activity. The different combinations of sol-gel precursors affected both activity and the stability of the enzymes, which suggests that each enzyme has a unique preference for the silica gel matrix dependent upon the characteristics of the precursors. The resulting enzyme-entrapped micronsized beads were characterized and utilized for several enzyme reaction cycles. These results indicated improved stability compared to the conventional crushed form silica sol-gel immobilized enzyme systems.

• 공업화학
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• 제2권1호
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• pp.56-63
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• 1991

1-(2-carbomethoxyacryloyl)-5-fluorouracil(CMAFU)을 trans-${\beta}$-carbomethoxyacryl chlocide와 2, 4-bis(trimethylsilyloxy)-5-fluoropyrimidine으로부터 합성하고, CMAFU와 메틸메타크릴레이트를 cyclohexanone을 용매로 사용하여 $60^{\circ}C$에서 라디칼공중합을 하였다. 5-FU, CMAFU 및 poly(CMAFU-Co-MMA)들이 노랑초파리에 미치는 생리유전학적 영향을 Lewis와 Bacher 방법에 의하여 조사한 결과, CMAFU와 그 중합체가 5-FU 보다 생리유전학적 영향이 약함을 알 수 있었다.

• 멤브레인
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• 제5권1호
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• pp.44-57
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• 1995

내부산의 탈거제로 탄산나트륨을 함유하는 유화액막의 거동을 묘사하기 위하여 수학적 모델이 제시되었다. 젖산의 회분식 추출 실험 결과가 모델의 계산 결과와 비교되었는데, 모델의 계산 결과는 담체농도, 탈거제농도, 교반속도, 처리비와 같은 변수의 영향을 잘 예측할 수 있었다. 유화액막의 주요 문제 중의 하나인 에멀젼의 팽윤을 줄이기 위하여, 액체 파라핀, n-데칸올, 사이클로헥사논, 스판-85 같은 막 첨가제가 사용되었다. 사용된 모든 첨가제는 팽윤 정도를 줄이는데 어느 정도 효과가 있었다. 사이클로헥사논은 팽윤을 줄일 뿐만 아니라, 젖산의 전달 속도를 크게 증가시키는 것으로 관찰되었다.

• Applied Biological Chemistry
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• 제31권3호
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• pp.298-307
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• 1988

토마토 과실의 저장 중 향기물질은 호흡 Climaceteric peak 시기와 함께 그 종류가 증가하였고 SAP-L이 NAP-N보다 향기성분 함량의 증가폭이 완만하였다. 향기성분 중 함량이 많은, 2-hexanone, n-propanol, n-pentanol 및 ethanol은 저장초기에 감소한 후 증가하였고, n-octanol과 furfural은 저장 전반에 걸쳐 증가한 반면 n-butanol, cyclohexanone 및 phenylacetaldehyde 등은 감소하였으며 trans, trans-2,4-decadienal, bensyl alcohol 및 2-heptanone 등은 거의 변화가 없었다.

• 공업화학
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• 제5권2호
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• pp.238-246
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• 1994

Fe(II) 또는 Fe(III)/picolinic acid 유도체로 구성된 착화합물을 이용하며 과산화수소에 의한 cyclohexane의 부분 산화반응을 수행하였다. Cyclohexanone과 cyclohexanol이 주된 생성물이었으며, one/ol비는 3~10이었다. Pyridine/acetic acid 혼합용매(부피비 2.5:1, pH 5.3)에서 가장 우수한 활성을 보였고, 반응온도는 $25{\sim}40^{\circ}C$가 최적이었다. Cyclohexyl hydroperoxide가 반응 중간체임을 확인하였고, adamantane의 부분 산화반응과 radical trap 첨가 실험의 결과로부터 반응은 대부분 non-radical 경로를 거쳐 진행됨을 알 수 있었다.

• Archives of Pharmacal Research
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• 제25권5호
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• pp.590-599
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• 2002

Eight rigid compounds designed as esterase-stable analogues of methyl 2,5-dihydroxycinnamate (1) were synthesized. These derivatives include 2-(2',5'-dihydroxybenzylidene)cyclopentenone (3a), 2-(2',5'-dihydroxybenzylidene)cyclohexanone (3b), 2,6-bis(2',5'-dihydroxybenzy-lidene)cyclohexanone (4b), 2,6-bis(2',5'-dihydroxybenzylidene)cyclopentenone (4a), (E)-3-(2',5'-dihydroxybenzylidene)pyrrolidin-2-one (5), (E)-5-(2',5'-dihydroxybenzylidene )-1,2-isothiazolidine-1,1-dioxide (6), 4-(2',5'-dihydroxyphenyl)-5H-furan-2-one (7), and 3-(2',5'-dihydroxyphenyl)cyclopent-2-ene-1-one (8). Among the eight compounds, the furanone 7 and cyclopentenone 8 showed the most potent cytotoxicity with $IC_{50}$ values of 0.39-0.98 $\mu\textrm{g}$/mL. Compound 8 was further brominated, phenylated and methylated at the a position to give three corresponding analogues, including 2-bromo-3-(2',5'-dihydroxyphenyl)cyclopent-2-ene-1-one (24), 3-(2',5'-dihydroxyphenyl)-2-phenylcyclopent-2-ene-1-one (27), and 3-(2',5'-dihydroxyphenyl)-2-methylcyclopent-2-ene-1-one (28). Among the three, the most enhanced activity was observed with the phenylated compound 27.

• Bulletin of the Korean Chemical Society
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• 제34권1호
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• pp.143-148
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• 2013

Novel titanium containing solid core mesoporous shell silica has been synthesized by using octadecyltrichloro silane and triethylamine. The synthesized material was characterized by various physicochemical techniques. The mesoporous character of the material has been revealed from PXRD studies. The presence of octadecyltrichloro silane and triethylamine in the sample has been confirmed from EDAX studies. TG/DTA analysis reveals the thermal characteristics of the synthesized material. The presence of titanium in the frame work and its coordination state has been studies by UV-vis DR studies and XPS analysis. Chemical environment of Si in the framework of the material has been studied by $^{29}SiMASNMR$ studies. The surface area of the material is found to be around $550\;m^2g^{-1}$ and pore radius is of nano range from BET analysis. The spherical morphology and particle size of the core as well as shell has been found to be 300 nm and 50 nm respectively from TEM analysis. The catalytic application of this material towards the synthesis of caprolactam from cyclohexanone in presence of hydrogen peroxide through ammoxidation reaction has been investigated. The optimum conditions for the reaction have been established. The plausible mechanism for the formation of core silica and conversion of cyclohexanone has been proposed.

• 한국산업보건학회지
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• 제5권1호
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• pp.104-118
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• 1995

This study was performed to evaluate factors affecting desorption of organic solvents collected on charcoal tube and to find out the optimum condition. Desorption efficiency for polar analytes was improved when several polar desorption solvents such as methanol, dimethylformamide(DMF), 2-(2-butoxyethoxy)ethanol were added to carbon disulfide($CS_2$). The best improvement was achieved when 10% dimethylformamide(DMF) in $CS_2$ was used as desorption solvent. During storage of polar analytes, recovery was greatly reduced. Especially, the recovery of cyclohexanone was decreased to 18.1 % after a month storage at $34^{\circ}C$. After two weeks storage, recovery of polar analytes was sharply decreased. Water adsorbed on charcoal interfered the recovery of polar analytes but didn't interfere that one of nonpolar solvent, toluene. When 10% DMF in $CS_2$ was used as desorption solvent, the effect of water on recovery was decreased, comparing with Desorption efficiency increased when analyte loading increased, and usage of 10% DMF in $CS_2$ decreased the loading effect. Increasing volume of desorption solvent was not effective to improve desorption efficiency of analytes when 10% DMF was used. Continuous shaking and sonication is not helpful to increase the desorption efficiency of analytes except cyclohexanone using 10% DMF. When silica gel used as adsorbent, methanol was better desorbent than dimethylsulfoxide. Analytes adsorbed on silica gel showed high recovery in low concentration and less affected by humidity. On the basis of this study, the following conclusions have been drawn. To improve the recovery of polar organic materials in air samples, it is necessary to analyze samples as soon as possible after they were collected. Otherwise, samples must be stored at low temperature. Using two components of desorption solvents, such as 10% DMF in $CS_2$, the effects of loading and humidity decreased for polar analytes such as methyl ethyl ketone and methyl isobutyl ketone. When work place has high humidity with low concentration of polar organic solvents, silica gel can be used as adsorbent, because it produces quantitative recovery for polar analytes at this condition. But it should be noted that high humidity makes breakthrough easy in silica gel samples.

• Archives of Pharmacal Research
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• 제16권1호
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• pp.68-70
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• 1993

The triketones 3-6 were obtained by alkylation of cyclopentanone or cyclohexanone with the appropriate cycloalkanone bis-mannich base (1) or (2). Schmidt reaction of the tricketones 3-6 afforded the corresponding trcyclic lactames 7-10 respectively. reduction of 7 and 9 gave compounds 11 and 12 respectively.