• 제목/요약/키워드: Benzoic acid

검색결과 394건 처리시간 0.03초

주 사슬에 유연 격자를 포함한 새로운 공중합체 (The new Copolymers which contain Flexible Spacers in the Main Chain.)

  • 김기식
    • 한국응용과학기술학회지
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    • 제16권3호
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    • pp.255-262
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    • 1999
  • The new copolymers which contain flexible spacers in main chain were prepared and their properties were studied. the copolymers were synthesized in the melt polymerization melted from diacetoxynaphthalene isomers, ${\alpha},{\omega}bis(4-carboxyphenoxy)$ alkanes and p-acetoxy benzoic acid in the molar ratio of 1:1:2 and characterized for the effects of structure of naphthalenediol isomer moieties and the spacers on thermal crystalline and liquid crystalline properties of the resulting polymers. Diacetoxy naphthalene isomers were used 1. 5-,1. 6-,2. 6-and 2. 7-disubstituted ones and the spacers was either tetramethylene or decamethylene. The polymer was characterized by elemental and spectropic analysis, differential scanning calorimetry (DSC) on a polaring microscope, wide-angle X-ray diffractometry and thermogravimetry (TGA). There glass transition temperatures (Tg) and melting temperature (Tm) on the structure of the naphthalenediol isomer moieties and the length of the spacers. The presence of spacers was found to the helpful in crystallization of 1. 6-naphthalenediol copolyesters. The presence of amide group in the backbone chain of polymer was found to increase transition temperature, crystallization, thermal stability of polymers but to decreas solubility.

Decolorization of Dyehouse Effluent and Biodegradation of Congo Red by Bacillus thuringiensis RUN1

  • Olukanni, O.D.;Osuntoki, A.A.;Awotula, A.O.;Kalyani, D.C.;Gbenle, G.O.;Govindwar, S.P.
    • Journal of Microbiology and Biotechnology
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    • 제23권6호
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    • pp.843-849
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    • 2013
  • A dye-decolorizing bacterium was isolated from a soil sample and identified as Bacillus thuringiensis using 16S rRNA sequencing. The bacterium was able to decolorize three different textile dyes, namely, Reactive blue 13, Reactive red 58, and Reactive yellow 42, and a real dyehouse effluent up to 80-95% within 6 h. Some non-textile industrially important dyes were also decolorized to different extents. Fourier transform infrared spectroscopy and gas chromatography-mass spectrometer analysis of the ethyl acetate extract of Congo red dye and its metabolites showed that the bacterium could degrade it by the asymmetric cleavage of the azo bonds to yield sodium (4-amino-3-diazenylnaphthalene-1-sulfonate) and phenylbenzene. Sodium (4-amino-3-diazenylnaphthalene-1-sulfonate) was further oxidized by the ortho-cleavage pathway to yield 2-(1-amino-2-diazenyl-2-formylvinyl) benzoic acid. There was induction of the activities of laccase and azoreductase during the decolorization of Congo red, which suggests their probable role in the biodegradation. B. thuringiensis was found to be versatile and could be used for industrial effluent biodegradation.

피부의 광반응 (Photoreactions of the Skin)

  • 배성수;박래준;김진상;권혁철
    • The Journal of Korean Physical Therapy
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    • 제4권1호
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    • pp.13-18
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    • 1992
  • Most of the electromagnetic agents used in physical therapy rely for their effects on tissue heating and photoreaction of the body. Infrared and untraviolet light on the other hand, owns its place in medicine because it produces direct photochemial reaction when it interacts with the body. This study was carried out to investigate and review for photoreaction of the akin. The results were an follows. 1. The effects of the infrared are heat production, increasing metabolism, increasing circulation, vasodilatation and pigmentation. 2. Directed photoreactions are divided into acute reaction and chronic reaction, and the acute reaction makes pigmentation from $290\~320nm$ of ultraviolet ray. 3. Ultraviolet ray formated pigmentations, which are melanoblasts excited from ultraviolet ray and received chemical stimulation, that make melanin granule. 4. If exposured with long duration, at ultraviolet ray, it makes skin thickening and epithelioma. 5. Indirected photoreaction is made by existenced hypersensitivity of photoreaction or lack of photodefence structure. 6. The phototoxic reactions are synthesized by chemical reaction of excitement from ultraviolet ray also this time analysis, synthesis and polymerization from energy of a circumferenced substance. 7. Sunscreen substances are P-amino benzoic acid and oxidate titan.

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Tetradiazo(o-carboxy)phenylcalix[4]arene for Determination of Pb2+ Ion

  • Tan, Le Van;Quang, Duong Tuan;Lee, Min-Hee;Kim, Tae-Hyun;Kim, Ha-Suck;Kim, Jong-Seung
    • Bulletin of the Korean Chemical Society
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    • 제28권5호
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    • pp.791-794
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    • 2007
  • A new azocalix[4]arene, 5,14,17,23-tetra[(2-benzoic acid)(azo)phenyl] calix[4]arene (2), has been prepared by hydrolysis of its ester derivative and characterized by 1H NMR, IR, UV-Vis spectroscopy and elemental analysis. Based on UV spectral changes, we found that 2 exhibits Pb2+ ion selectivity. In basic media, Pb2+ forms a 1:1 complex with the ligand. Beer's law is obeyed in the range of 2.0 × 10?6 ? 2.4 × 10?5 mol L?1 of Pb2+. The molar absorptivity (ε ) of 2-Pb2+ complex is 1.89 × 104 L mol?1 cm?1 at 440 nm, and the detection limit is 1.6 × 10?6 mol L?1.

LiNbO$_3$기판 위에서의 양자교환에 의한 공도파로 제작 (Fabrication of optical waveguide on LiNbO$_3$substrate by proton exchange)

  • 정상철;심광보;정용선;신재혁;오근호
    • 한국결정성장학회지
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    • 제10권4호
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    • pp.297-301
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    • 2000
  • H와 Li의 양자교환법에 의해 평면도파로와 channel도파로를 $LiNbO_3$단결정 기판위에 구현하였다. 양자원으로 피로인산을 사용하였고 평면도파로의 모드들에 대한 유효굴절률을 측정하였으며 반응시간과 반응온도로부터 광도파로의 깊이와 계단형 형태의 굴절률 변화에 대한 식을 구하였다. 이 식에서 구한 단일모드 도파 조건으로 channel 도파로를 제작하였고 입사광의 제한 효과를 관찰하였다.

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Development of a Single Chain Antibody Using a Phage Display Cloning Method for the Detection of 2,4-Dinitrotoluene

  • Na, Jung-Hyun;Joo, Man-Seok;Lee, Won-Kyu;Shim, Hyunbo;Lim, Si-Hyung;Jung, Sang Taek;Yu, Yeon Gyu
    • Bulletin of the Korean Chemical Society
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    • 제34권2호
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    • pp.460-464
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    • 2013
  • Single-chain variable fragments of antibodies (scFv) specific to 2,4-dinitrotoluene (DNT) were isolated from a phage library displaying synthetic human scFv fragments with 6 diversified complementary determining regions (CDRs). A DNT derivative that contained an extended amine group was synthesized and conjugated to the NHS-group that was linked to magnetic beads. Phages specific to the immobilized DNT derivatives were isolated from the library after 4 rounds of sequential binding and elution processes. The displayed scFv fragments from the isolated phages showed consensus CDR sequences. One DNT-specific scFv was expressed in E. coli and purified using Ni-affinity chromatography. The purified DNT-specific scFv binds specifically to the immobilized DNT-derivative with $K_D$ value of $6.0{\times}10^{-7}$ M. The scFv and DNT interaction was not disrupted by the addition of 4-nitrotoluene or benzoic acid. These data demonstrate that the screened scFv from the phage displayed library could be used for selective and sensitive detection of explosives such as TNT.

Effects of the Constituents of Paeonia lactiflora Root on Arachidonate and NO Metabolism

  • Choi, Yong-Hwan;Gu, Lianyu;Kim, Yeong-Shik;Kang, Sam-Sik;Kim, Ju-Sun;Yean, Min-Hye;Kim, Hyun-Pyo
    • Biomolecules & Therapeutics
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    • 제14권4호
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    • pp.216-219
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    • 2006
  • In order to establish the anti-inflammatory cellular mechanism of the paeony root(Paeonia lactiflora, Pall, Paeoniaceae), the constituents including paeoniflorin, albiflorin, (+)-catechin, paeonol, benzoic acid and methyl gallate were evaluated for their effects on arachidonate and NO metabolism. Among the compounds tested, only paeonol weakly inhibited cyclooxygenase-2-mediated $PGE_2$ production from LPS-treated RAW 264.7 cells. (+)-Catechin and methyl gallate weakly inhibited inducible nitric oxide synthase-mediated NO production from the same cell line. In particular, methyl gallate significantly inhibited 5-lipoxygenase from RBL-l cells with an $IC_{50}$ of 8.4 ${\mu}M$. These results suggest that the inhibition of these components on arachidonate and NO metabolism may contribute at least in part to anti-inflammatory mechanism of the paeony root.

액상한약제제의 보존제 모니터링 (Monitoring of preservatives in herbal liquid preparations)

  • 전종섭;조현례;김범호;조상훈;박신희;김영숙;윤미혜;이정복
    • 분석과학
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    • 제24권2호
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    • pp.127-134
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    • 2011
  • 본 연구에서는 기존 대한약전외 일반시험법 중 파라옥시안식향산에스텔 및 그 염류의 함량시험법의 이동상의 조성을 acetonitrile water (containing 1% glacial acetic acid) mixture (30:70 v/v)로 변화시켜 첨가제로 사용된 보존제성분과 제품에서 기인하는 방해물질과의 완전한 분리를 통하여 액상한약제제 분석의 효율성을 기하였다. 유통되고 있는 한약제제 중 액상제품 총 47품목을 대상으로 안식향산나트륨, 디히드로 초산나트륨, 파라옥시안식향산메칠, 파라옥시안식향산에칠, 파라옥시안식향산프로필 등 5종의 함량을 모니터링 하였다. 그 결과 액상한약제제 37품목 중 보존제가 표시된 31품목은 보존제가 표시된 함량에 맞게 함유되어 있었다. 안식향산과 디히드로초산이 함유된 7품목 중 6품목은 디히드로초산이 표시량에 비해 낮게 검출되었거나 검출되지 않았다. 보존제가 미표시된 10품목 중 3품목에서 보존제가 검출되었다. 3건 모두 안식향산이 검출되었고 그 중 2건에서 디히드로초산이 검출되었으며 1건에서 메틸파라벤이 검출되었다.

국내 판매중인 여성청결제의 사용실태 및 함유 보존제 분석 (Usage Patterns of Feminine Hygiene Products and Preservative Contents in Feminine Cleansers in the Korean Market)

  • 김완서;윤영인;이고운;박나연;고영림;최경호
    • 한국환경보건학회지
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    • 제44권2호
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    • pp.115-123
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    • 2018
  • Objectives: Preservatives, suspected to be endocrine disrupting chemicals, are widely used in feminine hygiene products for the prevention of deterioration. Information regarding the usage patterns of feminine hygiene products and the concentrations of preservatives in these products is limited. The present study was conducted to investigate the use of feminine cleansers among Korean women and quantify the concentration of preservatives in feminine cleansers. Methods: Approximately 500 women were recruited from the city of Busan in August 2017 and a questionnaire survey was conducted on the use of feminine cleansers. Several major feminine hygiene products (n=69) were identified and selected for analysis of 22 preservatives. Following appropriate preparation, the products were analyzed by HPLC/DAD. Results: Over 70% of the participating women used at least one feminine cleanser. Marital status and parity were associated with the frequency of use. Liquid was most frequently used form of feminine cleanser (66.6%). The greatest proportion of subjects answered that they use it 'one to two times per week' (36.5%). Among the 69 feminine cleansers, benzoic acid, sorbic acid, phenoxyethanol, and methyl paraben were detected at $144-4,428{\mu}g/g$, $195-1,470{\mu}g/g$, $269-4,237{\mu}g/g$, and $625-4,901{\mu}g/g$, respectively. BA was the most frequently detected (46.4%). Conclusions: In the present study, the characteristics of feminine cleanser use among Korean women were investigated. Based on an analysis of preservatives in the feminine hygiene products, one product was determined to exceed the maximum authorized concentration of MeP (0.4%). Our results will help refine exposure and risk assessment for toxic chemicals in feminine cleansers.

방동사니 전초의 항산화 페놀성 성분 (Antioxidant Phenolic Components from the Whole Plant Extract of Cyperus amuricus Max.)

  • 이사임;최훈;전훈;백남인;김성훈;김희자;조종현;안효초;양재헌;채병숙;임종필;은재순;김대근
    • 생약학회지
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    • 제39권3호
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    • pp.233-236
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    • 2008
  • In order to find the antioxidative components, fractionation of Cyperus amuricus (Cyperaceae) methanol extract was performed by measuring the DPPH (1,1-diphenyl-2-picrylhydrazyl) scavenging effect. Three compounds, 3,4-dimethoxy benzoic acid (1), 4-hydroxybenzoic acid (2), and piceatannol (3) were isolated from the active ethylacetate soluble fraction of C. amuricus through repeated silica gel and Sephadex LH-20 column chromatography. Among them, compound 3 showed the significant antioxidative effect on DPPH free radical scavenging test. These compounds are reported for the first time from this plant.