• Title/Summary/Keyword: Benzene

Search Result 1,928, Processing Time 0.027 seconds

Microbial degradation of the persistent pollutant TCAB : (II) -Degradation of TCAB by isolated microorganisms- (난분해성(難分解性) 공해물질(公害物質) TCAB의 미생물(微生物)에 의(依)한 분해(分解) : (II) -분리(分離) 균주(菌株)에 의(依)한 TCAB의 분해(分解)-)

  • Lee, Jae-Koo;Ihm, Yang-Bin;Cho, Yong-Gyun;Kyung, Kee-Sung;Oh, Kyeong-Seok;Kim, Hak-Nam
    • Applied Biological Chemistry
    • /
    • v.34 no.4
    • /
    • pp.299-306
    • /
    • 1991
  • When $[U-^{14}C]$ 3,3', 4,4'-tetrachloroazobenzene$([U-^{14}C]\;TCAB)$ was added to the $MM_2$ medium as a sole carbon source for the isolated microorganisms and incubated, some radioactive metabolites were detected by autoradiography. No $^{14}CO_2$ was evolved from $[U-^{14}C]\;TCAB$ which was added as a sole carbon source to an organic matter-free soil inoculated by the isolates, wetted with the $MM_2$ salt medium, and incubated at $30^{\circ}C$. One of the metabolites in pure culture of Achromobacter group VD, which was isolated and identified, was tentatively identified as a compound of m/z 250 by means of GC/MS. The possible pathways for its formation are thought to include dechlorination from the TCAB structure, hydroxylation, ortho fission of the two benzene rings, and reduction of the resulting carboxyl group.

  • PDF

Growth and Aromatic Constituents of Wild and Domesticated Codonopsis lanceolata Grown at Two Different Regions (야생 및 재배더덕의 재배장소에 따른 생육 및 향기성분)

  • 이승필;김상국;최부술;이상철;김길웅
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.40 no.5
    • /
    • pp.587-593
    • /
    • 1995
  • Growth characteristics and aromatic constituents of wild and domesticated Codonopsis lanceolata grown in different regions were investigated to find the best cultural condition for quality improvement. The results were as followings: Air temperature of wild region was lower to 4~8 and soil temperature was also lower to 3 compared with domesticated region. Soil of wild region had about three times richer organic matter with lower pH. Chromosome number of wild and domestcated species was 2n=16, ovary number was 3, but seed number of wild species was 132 vs domesticated showing 62. Recovery yield of wild species grown wild region had 0.55%, besides that, the wild species grown in domesticated region had 0.34. But the domesticated species in wild and domesticated regions was the same as 0.28. Inorganic element contents of domesticated region showed much higher than that of wild region. Major aromatic constituents were specified in wild Codonopsis lanceolata as dimethyl benzene, 3-ethyl-5-2-(ethylbutyl)-octadecane, benzaldehyde, 14, 14-dimethyl-hexadecanoate, methylhexadecenoate of which was not detected in domesticated species.

  • PDF

Effect of the Sulfur Removal in Manufacturing Pt/C Electrocatalysts on the Performance of Phosphoric Acid Fuel Cell (인산형 연료전지용 백금촉매제조에서 황의 제거에 따른 전극 성능)

  • Shim, Jae-Cheol;Lee, Kyung-Jik;Lee, Ju-Seong
    • Applied Chemistry for Engineering
    • /
    • v.9 no.4
    • /
    • pp.486-490
    • /
    • 1998
  • Pt/C powder which was used as electrocatalyst in a Phosphoric Acid Fuel Cell(PAFC) was fabricated by colloid method. It was reported that the sulfur from reductant, $Na_2S_2O_4$, worked as a poison against catalyst during long term operation. To remove these sulfurs, we try to treat Pt/C powder by three different methods. First, we tried to remove the sulfur according to temperature and time in $H_2$ atmosphere. As the heat treatment temperature is raised up, the effect of the removal is increased but the electrode performance is decreased because of the growth of Pt particle size. The optimal heat treatment temperature is $400^{\circ}C$, the size of Pt particle is approximately $35{\sim}40{\AA}$ and the electrode performance is $360mA/cm^2$ at 0.7 V. At $400^{\circ}C$, even though the time of heat treatment is extended, size of Pt, amounts of remaining sulfur and electrode performance is almost constant. Secondly, when we removed in a crucible at $900^{\circ}C$ the removal of the sulfur was not better, but the size of Pt particle, approximately $80{\AA}$, was smaller than that of heat treatment in $H_2$ atmosphere at $900^{\circ}C$. Lastly we treated with solvents such as acetone, benzene, and carbon disulfide. It was observed that sulfur components were removed partly by extraction with solvents, the electrode performances were similar each other.

  • PDF

Antioxidative Effects of Soybean Extracts by using Various Solvents (다양한 용매를 이용한 대두 추출물의 항산화효과)

  • Kim, Jee-Young;Maeng, Young-Sun;Lee, Ki-Young
    • Korean Journal of Food Science and Technology
    • /
    • v.27 no.5
    • /
    • pp.635-639
    • /
    • 1995
  • The effective extraction of antioxidative substances from soybean was investigated by using various solvents, such as water, ethanol, methanol, acetone, chloroform, benzene, ethyl acetate, ether, dichloromethane, and hexane. Extraction was performed by cold method at $30^{\circ}C$ and by reflux method at $85^{\circ}C$. The antioxidative effect of the extracts was determined by peroxide value during the oxidation of soybean oil containing the extracts at $105^{\circ}C$ for 10 hours, and also by TBARS(thiobarbituric acid reactive substances) formed during the peroxidation of egg lecithin liposomes. The antioxidant activity of the extracts from raw soybean was higher than that from defatted soybean. The antioxidant activity of the extracts by reflux method was higher than that by cold method. The methanol extract from defatted and roasted soybean(DRS) showed the highest antioxidative effect against oxidation of soybean oil, while the water extract from DRS in egg lecithin liposomes. In the peroxidation of egg lecithin liposomes, the antioxidative effect of polar solvents extracts were higher than those by nonpolar solvents extracts.

  • PDF

Volatile Flavor Components in Mash of Takju prepared by using Rhizopus japonicus Nuruks (Rhizopus japonicus 누룩으로 담금한 탁주 술덧의 발효 과정 중 휘발성 향기성분)

  • Lee, Taik-Soo;Han, Eun-Hey
    • Korean Journal of Food Science and Technology
    • /
    • v.32 no.3
    • /
    • pp.691-698
    • /
    • 2000
  • Volatile flavor components in the mash of takjus prepared by using Rhizopus japonicus nuruk were identified by using GC and GC-MS. Twenty-four esters, 19 alcohols, 9 acids, 10 aldehydes and 4 others were found in the mash of takju. Thirty nine components including 14 esters and 12 alcohols were detected in the beginning of fermentation. Seventeen components were more detected after second day of fermentation and 66 components were detected after 12 days of fermentation. Thirty eight flavor components including 12 alcohols such as ethanol, 2-methyl-1-propanol and 3-methyl-1-butanol, 14 esters such as ethylacetate, ethylcaprylate and isoamylacetate, 6 aldehydes and 5 acids were usually detected in the fermentation process. Ethanol was predominantly found in the range of 76.2149-92.1155% as a major component by using relative peak area. 3-Methyl-1-butanol, 2-methyl-1-propanol, ethyl caprylate, 2,3-butanediol and benzeneethanol were some of the major volatile components through the fermentation. Peak area of ethylacetate, diethyl succinate, octanoic acid, acetic acid and isobutylaldehyde among the same group were higher than other component depending upon fermentation time.

  • PDF

Characterization of the Quinoline-Degrading Bacterium Pseudomonas sp. NFQ-1 Isolated from Dead Coal Pit Areas (폐광지역에서 분리한 quinoline 분해 세균인 Pseudomonas sp. NFQ-1의 특성연구)

  • 윤경하;황선영;권오성;오계헌
    • KSBB Journal
    • /
    • v.18 no.3
    • /
    • pp.174-179
    • /
    • 2003
  • The bacterium NFQ-1 capable of utilizing quinoline (2,3-benzopyridine) as the sole source of carbon, nitrogen and energy was enriched and isolated from soil samples of dead coal pit areas. Strain NFQ-1 was identified as Pseudomonas nitroreducens NFQ-1 by BIOLOG system, and assigned to Pseudomonas sp. NFO-1. Pseudomonas sp. NFQ-1 was used with the concentration range of 1 to 10 mM quinoline. Strain NFQ-1 could degrade 2.5 mM quinoline within 9 hours of incubation. Initial pH 8.0 in the culture was reduced to 6.8, and eventually 7.0 as the incubation was proceeding. 2-Hydroxyquinoline, the first intermediate of the degradative pathway, accumulated transiently in the growth medium. The highest concentration of quinoline (15 mM) in this work inhibited cell growth and quinoline degradation. Pseudomonas sp. NFQ-1 was able to utilize various quinoline derivatives and aromatic compounds including 2-hydroxyquinoline, p-comaric acid, benzoic acid, p-cresol, p-hydroxybenzoate, protocatechuic acid, and catechol. The specific activity of catechol oxygenases was determined to approximately 184.7 unit/㎎ for catechol 1.2-dioxygenase and 33.19 unit/㎎ for catechol 2,3-dioxygenase, respectively. As the result, it showed that strain NFQ-1 degraded quinoline via mainly orthp-cleavage pathway, and in partial meta-cleavage pathway.

EFFECT OF ZIZYPHI FRUCTUS EXTRACT ON THE BIOLOGICAL ACTIVITY OF GINGIVAL FIBROBLAST (대조 추출물분획이 치은 섬유아세포의 생물학적 활성화에 미치는 영향)

  • Yang, Chang-Ho;Lee, Yong-Moo;Cho, Ki-Yeong;Bae, Ki-Hwan;Chung, Chong-Pyoung
    • Journal of Periodontal and Implant Science
    • /
    • v.24 no.1
    • /
    • pp.144-154
    • /
    • 1994
  • Final goal of periodontal treatment is to reconstruct the destructed periodontal tissue as well as to remove the necrotic pathologic elements. The purpose of this study is to investigate on the effect of Zizyphi extract to the inhibitory ability on collagenolytic activity of P gingivalis, biologic activity of gingival fibroblasts, and on the collagen and protein synthesis of gingival fibroblasts. Gingival fibroblast from giniva of first bicuspids from patient for orthodontic treatment were used and cultured. For the measurement of inhibitory ability of collagenolytic activity, crude enzyme was extracted and used on the basis of modified Ono's method. On the inhibition of collagenolytic enzyme from herbal extracts, collagenokit CLN-100 were used. The cellular activity of gingival fibroblast, were studied using MTT solution and measured optical density on 570mm by ELISA reader. To measure the effects on the ability of whole protein and collagen synthesis, cell membrane was destructed with ultrasonic grinder after culturing, centrifuged and counted by liquid scintilation counter. The inhibitory effects on producing of $IL-l{\beta}$ by monocyte, after promotion of producing $IL-l{\beta}$ by LPS, were compared with the mixture of herbal extracts and other drugs using thymocyte stimulation assay. About inhibitory effects of $PGF_2$. by gingival fibroblasts, herbal extract was compared with the addition of the other control groups using enzyme imunoassay. On the inhibition of collagenolytic activity by P. gingivalis, benzene extracts showed the most efficient inhibitory effects among the $19{\mu}g/ml$ of the compared extracts and 40.5% by Tetracycline. On the cellular activity promoting effects, compared extracts showed a bit of more effects than PDGF of $100{\mu}g/ml$ concentration and IGF of $20{\mu}g/ml$ concentration. All of the PDGF, IGF, Zizyphi Fructus extract should increase in collagen synthesis, but especially 70% ethylalcohol extracts of Zizyphi Fructus showed comparably high effects among the compared extracts. Effects on whole protein synthesis were slightly increased on every extract but especially 70% ethylalcohol extract showed significantly effective than any other estract. On the inhibitory effects of Zizyphi Fructus $IL-l{\beta}$ production by monocyte, compared extracts showed 70% of highly inhibitory effect than that of 60% inhibition effects on controlled group and each extracts showed no significant difference. In $PGF_2$ production inhibitroy effect of Zizyphi Fructus gingival fibroblasts, Herbal extracts showed 70% of inhibition comparing with tat of 90.2% of controlled group, but each extracts showed similar effects excluding the $H_2O$ extracts. These results suggested that Zizyphi Fructus might be useful medicine for inhibition of inflammatory mediator including $IL-l{\beta}$ and $PGF_2$.

  • PDF

A Study of the Retention Mechanism of the Monosubstituted Benzenes in Reversed-phase Liquid Chromatography (II) (역상 액체크로마토그래피에서 벤젠 일치환체들의 머무름 메카니즘에 관한 연구 (제 2 보))

  • Lee, Dai-Woon;Choi, Yong-Wook;Lee, Won
    • Journal of the Korean Chemical Society
    • /
    • v.32 no.2
    • /
    • pp.135-143
    • /
    • 1988
  • The correlations between chromatographic parameters of monosubstituted benzenes and several physical parameters in reversed phase liquid chromatography were studied. The relationships between retention data and polarity index were investigated by plotting $log(log k'_S/k'_B)$ vs. $P'_S/P'_B$ which were relative retention and relative polarity index of monosubstituted benzenes with respect to benzene, respectively. The linear relationship between relative retention and polarity index was observed for the monosubstituted benzenes having polar group, while in case of those having nonpolar group, the good linearity was observed by combination with relative molecular weight i.e. $(P'_S/P'_B)/(MW_S/MW_B)$. Multivariant regression analysis, $a(P'_S/P'_B)+b(MW_S/MW_B)$+c did not give significantly better correlations compared to single variant analysis, $a[(P'_S/P'_B)/(MW_S/MW_B)]$+c, but multiple stepwise regression analysis was recommended when several physical parameters simultaneously were chosen. The best correlation between retention data for monosubstituted benzenes taken from the literature and substituent constant(${\pi}$), derived from hydrophobic parameter and the first order molecular connectivity index$(^1{\chi}^{\nu})$, was established for methanol/water mobile phase system. The larger the surface coverage of the stationary phase, the higher was the correlation coefficient between these two parameters and retention data.

  • PDF

Prediction of Retention Indices of Various Compounds in Gas-Liquid Chromatography (기체-액체 크로마토그래피에서 화합물의 머무름 지표의 예측에 관한 연구)

  • Cha, Gi Won;Lee, Deok Jae
    • Journal of the Korean Chemical Society
    • /
    • v.38 no.2
    • /
    • pp.108-121
    • /
    • 1994
  • The retention indices of branched-chain alkane, benzene ring, alcohol, amine, ketone, aldehyde and cyclic compounds were measured at 150, 180 and $210^{\circ}C$ on OV-1701 and OV-1 capillary columns. The group retention factors (GRF) of the substituents and the st` ructure retention factors (SRF) of the molecular structure change are derived from the retention indices of reference compounds and series of homologues. The $GRF_f$ equation of `f'th substituent is $GRF_f\;=\;I_{obs}-(100Z + \sum\limits_{i{\neq}f}GRF_i$ + {\sum}$SRF_i$)and the SRFf equation of `f'th molecular structure group is $SRF_f\;=\;I_{obs}-(100Z + {\sum}GRFi + \sum\limits_{i{\neq}f}SRF_i$). The predicted retention indices for those compound were in agreement, within the error of $\pm2$ and $\pm3%$, with the observed values that were obtained using the OV-1701 and OV-1 capillary column, respectively. The $\Delta$ xi of the substituents and $\Delta$ yi of the molecular structure change according to temperature change are derived from the $\Delta'/^{\circ}C$ of reference compounds and series of homologues. The $\Delta$ xi equation of the `f'th substituent is ${\Delta}x_f = {$\Delta}'/^{\circ}C+ \sum\limits_{i{\neq}f}\Delta$ xi + {\sum}{\Delta}yi\;and\;{\Delta}yi$ equation of the `f'th molecular structure group is ${\Delta}y_f$ = {\Delta}'/^{\circ}C+{\sum}{\Delta}xi +\sum\limits_{i{\neq}f}{\Delta}yi$. The predicted $\Delta'/^{\circ}C$ for these compounds were in agreement, within the error of ${\pm}18%$ and 17%, with the observed values that were obtained using the OV-1701 and OV-1 capillary column, respectively.

  • PDF

Gas Chromatographic and Mass Spectrometric Determination of Alcohol Homologues in the Korean Folk Sojues (Distilled Liquor) (기체크로마토그래피 및 질량분석법에 의한 민속 소주중의 알코올 동족체 분석)

  • Lee, Dong Seon;Park, Hye Seong;Kim, Geon;Lee, Taek Su;No, Bong Su
    • Journal of the Korean Chemical Society
    • /
    • v.38 no.9
    • /
    • pp.640-652
    • /
    • 1994
  • This work is undertaken to determine alcohol homologues so-called fusel oil that may be present in the Korean folk sojues (distilled liquor) made from grains and to describe sample preparation and analytical method by GC-FID-MS. Solid phase extraction method for sample preparation by using porous styrene divinyl benzene polymer (Porapak Q) was compared with steam distillation and solvent extraction method. Retention behaviors of homologous series of alcohols were also studied. Log values of retention time, molecular weight, boiling point, and capacity factor of alcohols showed linear correlations to the carbon number of an alcohol, to the oven temperature, and to the dielectric constant. Components such as methyl alcohol, n-propyl alcohol, isobutyl alcohol, isopentyl alcohol, and phenethyl alcohol have been identified. The more amount of isopentyl alcohol than other alcohols are contained in the Korean folk sojues, while that of n-propyl alcohol are contained in Chinese kaoliangchiew. Degree of similarity or dissimilarity and classification of the individual samples were discussed using multivariate statistical analysis(principal components analysis) based on GC data.

  • PDF