• Title/Summary/Keyword: cyclobutane

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Fluorescent Crack Sensor in a Polymeric Material (고분자 재료의 형광 크랙센서)

  • Cho, Sung-Youl;Kim, Ji-Eun;Kim, Joong-Gon;Chung, Chan-Moon
    • Polymer(Korea)
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    • v.32 no.2
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    • pp.189-192
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    • 2008

  • A styrylpyrylium salt (DHSP) was synthesized and then photodimerized to obtain a cyclobutane-type dimer (DHSP dimer). Methacryloyl group was incorporated into DHSP dimer to obtain DMSP dimer. Based on FT-IR analysis of a crosslinked DMSP dimer, it was considered that the cyclobutane structure reversed to styryl C=C bonds upon crack formation. Fluorescence measurement of DHSP in solid state (excitation at 385 nm) showed emission centered at 626 nm, while DHSP dimer revealed very weak emission. Fluorescent emission from microcracks in a film of crosslinked DMSP dimer was observed upon exposure to $330{\sim}385\;nm$ light.

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Occurrence of ELISA Inhibitors, and Inhibitor-free Determination of Cyclobutane Pyrimidine Dimers in Japanese Cypress Leaves

  • Hashimoto, Tohru;Nakagawa, Noriko;Okano, Michiaki;Nikaido, Osamu
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.448-450
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    • 2002

  • DNA samples extracted from Japanese cypress leaf tissues contain isopropyl alcohol-precipitable, high molecular weight compounds, which interfere ELISA for cyclobutane pyrimidine dimers (CPD). Removal of the compounds is achieved by DEAE ion-exchange column chromatography and improves the ELISA responses of the DNA. When extracting DNA repeatedly from the same leaf tissues, the DNA samples show CPD responses which increase with the order in sequential extraction, and hence for a reliable detennination of DNA lesion a thorough extraction of DNA is required. Clearing these two problems it was demonstrated that CPD level was slightly higher in the leaves of trees growing under full sunlight than in those growing under UBV -cut sunlight.

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The Preparation and Reactions of Some Fluorinated Cyclobutane Carboxylic Acids

  • J. D. Park;F. E. Rogers
    • Journal of the Korean Chemical Society
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    • v.16 no.3
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    • pp.178-188
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    • 1972

  • Diethyl itaconate was found to react tetrafluoroethylene, trifluorochloroethylene, and 1,1-difluoro-2,2-dichloroethylene quite rendily at $180^{\circ}C$ to form 1-carboxy-2,2,3,3,-tetrahalo-cyclobutane ethanoic acid derivatives ${C{\underline{X_2-CF_2-CH_2-}}C-(COOEt)-CH_2COOEt$, where X is Cl or F). Diethylcitraconate failed to yeild any cycloaddition products. The Physical and Chemical properties of the above esters and their dericatives are characterized and compared with other similar ring compounds.

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