• Biomolecules & Therapeutics
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• 제5권2호
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• pp.215-221
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• 1997

In an effort to screen new selective antitumor agents from the broth of soil microorganism, cytotoxicity oriented screening was performed against tumor cells and 3 compounds (Compound 1, 2 and 3) were isolated from Sreptomyces parvullus ISP 5048 and their chemical structures were determined. Among these compounds, Compound 2 showed the highest cytotoxicity against P388Dl and L1210. While the $IC_{50}$/ values of compound 2 against P388Dl and L1210 were 0.073$\mu$g/ml and 0.07$\mu$g/ml, respectively, and the $IC_{50}$/ value of Compound 3 was 0.17$\mu$g/ml against human lung cancer cells, A549, the cytotoxicity of Compound 2 and 3 against normal cell line, Vero E6 cell was about 4- and 8-fold lower than that of adriamycin. Based on the chemical analysis data, Compound 3 was octacosamicine A, a known antibiotic, which was reported by Dobasih et al. (1988). Taken together the results demonstrated that Compound 2 and Compound 3 has the possibility to be developed as antitumor agent because of its potent cytotoxicity as well as high selectivity against various cancer cell lines.

• 한국대기환경학회지
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• 제14권2호
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• pp.153-160
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• 1998

The concentrations of volatile organic compounds (VOCs) in the atmosphere were measured from the Yochon Industrial Estate and compared with those from Tongkwangyang and Seoul. The first important phenomenon observed in the air of Yochon was high concentrations of alkenes and in particular, ethylene and propene. For most dominant species, their means and standard deviations were high simultaneously. Concentrations of several major aliphatic species exhibited a similar pattern of diurnal variation, however, with different species combination on each day. Concentrations of several hazardous aromatic species also exhibited a similar pattern of diurnal variation on the same day, which was different from that observed in the diurnal variation of major aliphatic species. It was interpreted that some species were intermittently released from relevant processes. It was also understood that high concentrations and variations of VOC species in Yochon were localized and not related to high average concentrations of ozone in Yochon and Tongkwangyang areas.

• Bulletin of the Korean Chemical Society
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• 제28권3호
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• pp.403-407
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• 2007

The anodic degradation of benzoquinone(BQ), a model compound for wastewater treatment was carried out using a home-made flow-through electrochemical cell with carbon fibers. To optimize the controlled current electrolysis condition of an aqueous BQ solution, the experimental variables affecting the degradation of BQ, such as the applying current, pH, reaction time, and flow rate of the BQ solution were examined. The degradation products of the oxidation reaction were identified by High Performance Liquid Chromatography and Inductively Coupled Plasma Atomic Emission Spectrometer. Low molecular weight aliphatic acids, and CO2 were the major products in this experiment. The removal efficiency of BQ from the solution increased with the applying current and time. 99.23% of 1.0 × 10-2 M BQ was degraded to aliphatic acids and CO2 when the applying current is 175 mA in a 12 hr electrolysis.

• Archives of Pharmacal Research
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• 제24권4호
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• pp.300-306
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• 2001

A novel and two known bioactive mono-tetrahydrofuran (THF) annonaceous acetogenins, annomocherin (1), annonacin (2) and annomontacin (3), have been isolated from the fractionated ethanolic extracts of the seeds of Annona cherimolia, guided by the brine shrimp lethality test (BST). Their structures were elucidated on the basis of spectroscopic and chemical methods. All compounds have a relative stereochemistry of threo/trans/threo for the mono-THF ring with two flanking hydroxyls. Compound 1 has a double bond at C-23/ 24 of aliphatic chain. Compound 1 was isolated from natural sources for the first time, and was named annomocherin. Two known Compounds 2 and 3 which have never been isolated from this species before, were obtained. Compound 1 exhibited potent and selective cytotoxicities against the breast carcinoma (MCF-7) and kidney carcinoma (A-498) cell lines with 100 to 1,000 times the potency of adriamycin. In brine shrimp lethality test (BST), 1-3 exhibited cytotoxicity.

• Bulletin of the Korean Chemical Society
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• 제17권8호
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• pp.720-724
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• 1996

Catecholalane (1,3,2-Benzodioxaluminole, CA) prepared from catechol and aluminum hydride in tetrahydrofuran (THF) is found to be a selective reducing agent. The systematic study in order to characterize the reducing properties of the reagent under practical conditions (THF, 0 or 25 ℃, the quantitative amount of reagent to compound) has been done. The reagent reduces aldehydes, ketones, esters and acid chlorides to the corresponding alcohols, and primary amides to the corresponding amines. Especially noteworthy is that the reagent can convert both aromatic and aliphatic nitriles to the corresponding aldehydes in very high yields.

• 한국염색가공학회지
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• 제13권3호
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• pp.172-179
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• 2001

In order to improve dye uptime and wash fastness on dyeing of cotton fabrics with Amur cork tree, twitter ionic groups, acid groups, hydrophobic groups or cross linkage were introduced into cotton fabrics. Results obtained were as follows, 1 The optimum modification of cotton fabrics was carbosy methylation in the water solution containing 15% sodium chloroacetate and 15% sodium hydroxide and then introducing hydrophobic groups by treating in the solution containing $30m\ell$ DMSO and $3m\ell$ 2,4-TDI 2. Numbers of carbon, diisocyanate group than monoisocyanate group and aromatic compound than aliphatic compound in introduced hydrophobic groups were effective. 3. The dye uptake and wash fastness wore enhanced significantly by treating only with 2,4-TDI. 4. The wash fastness seems to correlate to the degree of swelling of the fabric during washing and also depend on the Interaction between dyes and acid groups as well as hydrophobic groups.

• 폴리머
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• 제33권3호
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• pp.198-202
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• 2009

Poly(ethylene terephthalate)(PET)의 올리고머인 oligo(ethylene terephthalate)(OET), oligo(ethylene succinate-co-terephthalate)(OEST) 및 oligo(butylene succinate-co-terephthalate)(OBST)를 각각 합성한 후, Pseudomonas cepacia 유래의 lipase PS를 사용하여, 올리고머의 분해실험을 실시, 분해시간에 의한 잔존중량 및 분해생성물의 분석에 의한 생분해기구를 해명함을 목적으로 하였다. OEST와 OBST의 합성에서는 배합 몰비에 대한 조성비의 조절이 가능한 올리고머를 얻을 수 있었으며, 조성비의 상이함에 의해 열적 성질이 현저한 차이가 있음을 확인하였다. 분해실험에서는 OEST, OBST 모두 lipase PS에 의해 분해가 발생되나, terephthalic acid의 조성이 높아질수록 분해능력이 저하됨을 확인하였고, lipase PS는 지방족에 가까운 조성을 가진 polyester를 쉽게 분해시킴을 확인하였다.

• 한국응용과학기술학회지
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• 제8권1호
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• pp.59-67
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• 1991

The reactions of semicarbazide hydrochloride with aliphatic and alicyclic ketones were studied kinetically at 15, 25, 35 and 45$^{\circ}C$ in 20% ethanol solution buffered at pH 2.9. The rate of cyclohexanone semicarbazone formation is 5.5 times as fast as that of cyclopentanone semicarbazone, while 3-pentanone semicarbazone is 4.7 times as slow as that of 2-pentanone, The activation energy of cyclohexanone, 2-pentanone, 2 hexanone, cyclopentanone, 4-methyl-2-pentanone and 3-pentanone semicarbazone formation are calculated 5.08, 7.52, 8.79, 9.59, 9.49, 11.59, respectively. It is concluded from the effect of ionic strength that the reaction is affected by not ion but neutral molecules being progressed hydrogen bond between oxygen atom of carbonyl group and hydrogen atom of acid-catalyst and concerted nucleophilic attack of free base on the carbonly compound. Dependence on pH of the rate of 2-pentanone semicarbozone formation is linear relationship below pH 4.60 and above pH 5.60. As a result of studing citric acid catalysis, second order constants increase linearly with citric acid concentration. As the catalyst concentration is varied from 0.025 to 0.10 mol/1 at pH 2.90, the rate constants increase 1.4 times, but slight increase is observed at pH 5.60. Conclusively, the rate-determining step is formation of tetrahedral interemediate below pH 4.65 and dehydration between pH 5.60 and pH 7.11. It is concluded that the formation reaction of cyclohexanone semicarbazone is faster than cyclopentanone semicarbazone due to the steric strain in the process of forming tetrahedral intermediate.

• 한국대기환경학회지
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• 제19권4호
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• pp.363-376
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• 2003

In this study, the fugitive emission characteristics of airborne volatile organic compounds from different source categories were evaluated with respect to the concentrations measured in the vicinity of the sources. A total of 22 different sources were investigated, including gasoline storage and filling stations, painting spray booth, laundry, printing officer, textile industries, and a number of environmental sanitary facilities such as landfill, wastewater treatment and incineration plants. The target VOCs included 83 individual compounds, which were determined by adsorption sampling and thermal desorption coupled with GC/MS analysis. Overall, the aliphatic compounds appeared to be the most abundant class of compounds in terms of their concentrations, followed by aromatic, and halogenated hydrocarbons. As a single compound, however, toluene was the most abundant one, explaining 11% of the total VOC concentrations as an average of all the dataset. Among source categories, petroleum associated sources such as gasoline storage/filling stations, and laundry factory were identified as the most significant sources of aliphatic hydrocarbons, while aromatic VOCs were dominantly emitted from the sources handling organic solvents, such as painting booth, printing offices, and textile dyeing processes. However. there was no apparent pattern in terms of the contributions of eath group to the total VOCs concentrations in environmental sanitary facilities. It was also found that the activated carbon adsorption tower installed for the VOC emission control in some facilities do not show any effective performances, which may result in the increased VOC levels in the ambient atmosphere.

• Journal of Korean Society for Atmospheric Environment
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• 제19권E3호
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• pp.129-136
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• 2003

Effects of inorganic aerosols on the kinetics of the hydroxyl radical reactions with selected aliphatic alkanes have been investigated using the relative rate technique. The relative rates in the absence and presence of aerosols were determined for n-butane, n-pentane, n-hexane, n-octane, and n-decane. P-xylene was used as a reference compound. Inorganic aerosols including (NH$_4$)$_2$SO$_4$, NH$_4$NO$_3$, and NaCl aerosols at two different aerosol concentrations that are typical of polluted urban conditions were tested. Total surface areas of aerosols were 1400 (Condition I) and 3400 $\mu$$m^2$ cm$^{-3}$ (Condition II). Significant changes in the relative rates in the presence of the inorganic aerosols were not observed for the n-butanel/$.$OH, n-pentanel/$.$OH, n-hexanel/$.$OH, n-octanel/$.$OH, and n-decanel/$.$OH reactions versus p-xylenel/$.$OH reaction. These results suggest that the promoting effects depend on the semiconducting property of the aerosols and the nature of the organic compounds.