• Journal of Nutrition and Health
• /
• v.27 no.4
• /
• pp.347-355
• /
• 1994

Indolo[3,2-b]carbazole(ICZ) is a potent Ah receptor agonist with biological activities similar in several respects to those of the potent environmental toxin, TCDD. ICZ is produced during the oilgomerization of indole-3-carbinol(I3C), a breakdown product of the glucobrassicin present in food plants of the Brassica genus. In the present study we examined ICZ levels in tissues and excreta of rats treated with I3C or dietary cabbage of established glucobrasicin content, and in feces of conventional and germfree rats fed on a basal diet, and of humans. We also examined the levels of cytochrome P4501A1 induction, as determined by the ethoxyresorufin ο-deethylase assay, in tissues of animals that received cabbage-supplemented diets, or which were treated with purified I3C or ICZ. Our findings indicated that incorporation of either homogenized or whole freeze-dried cabbage in the feed led to large increases(16-60 fold) in the levels of ICZ in the feces and lower gastrointestinal tract of rats. We observed that whereas ICZ is readily detectable at about the same levels(2.00$\pm$0.50 ppb) in the feces of conventional rats fed on a purified diet and in human feces, levels of ICZ in the feces of germfree animals fed on the basal diet were at the limits of detection(0.40$\pm$0.20 ppb), indication that gut bacteria are important for the production of ICZ from essential dietary constituents in the basal diet. We showed that in contrast to the near 7000-fold difference in CYP1A1 inducing potencies of ICZ and TCDD in cells in culture, their inducing potencies differ by only about an order of magnitude in rats. Nonetheless, the levels of ICZ remaining in livers twenty hours after I3C treatment appear too low to account for the induced activity. This result indicates that ICZ may be rapidly cleared from the liver or that substances other than, or in addition to, ICZ be responsible for the enzyme-inducing activity of orally administered I3C or its precursors.

• Korean Journal of Food Science and Technology
• /
• v.32 no.1
• /
• pp.147-153
• /
• 2000

We could produce algin-like biomaterial of polyiduronan using polyglucuronic acid C5-epimerase with polyglucuronic acid prepared by specific oxidation of primary alcohol groups of four kinds of polysaccharides(corn starch, rice starch, sweet potato starch, and cellulose). The enzyme activity was determined by the modified Dische carbazole methodology with the isolated crude enzyme from the supernatant centrifuged at $100,000{\times}g$ for 1 hr after grinding fresh bovine liver. And then, the optimal substrate, pH, and temperature for the enzyme reaction of polyglucuronic acid C5-epimerase were determined as the oxidized sweet potato starch, 7.0, and $30^{\circ}C$, respectively. Conclusively, it could be possible to epimerize polyglucuronic acid in the oxidized sweet potato starch to polyiduronic acid. Therefore, we could obtain algin-like polysaccharide using the oxidized sweet potato starch and polyglucuronic acid C5-epimerase isolated from bovine liver.

• Fibers and Polymers
• /
• v.2 no.3
• /
• pp.159-163
• /
• 2001

Five yellow disperse dyes were synthesized and their dyeing, fastness and photodegradation behaviors were investigated. It was found that dyes derived from phenylindole and N-alkylaminobenzene showed dye uptake directly proportional to the dye concentration, but the build-up of dyes derived from carbazole and pyridone were not good. The wavelength at maximum absorption. molar extinction coefficient. and the tendency to the photodegradation were strongly dependent on the electron donating ability of the coupling component. The dye, whose coupling component was phenylindole, possessed the excellent dyeing properties and the high degree of lightfastness. UVA had an effect on the inhibition of the photodegradation especially for the easily photodegradabte dyes.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2008.10a
• /
• pp.454-457
• /
• 2008

We report the syntheses, photophysical properties and device performances of solution processible host material for green-phosphorescent OLEDs. The butterfly-shaped new host materials with nonconjugated linkage of carbazole and fluorene moieties have large triple energy band gap around 2.8 eV. All of the EL devices exhibited turn-on voltages in the range of 4.8-5.0 V. GH-4 exhibited the best performance with a maximum current efficiency and power efficiency of 21.1 cd/A and 7.9 lm/W.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07b
• /
• pp.1381-1382
• /
• 2005

We report improved efficiency in blue electrophosphorescent organic light emitting diodes by introducing an interfacial exciton blocking layer between light emitting layer (EML) and hole transport layer (HTL). Iridium(III) bis [(4,6-di-fluorophenyl)- pyridinato -N,C2']picolinate (FIrpic) was used as blue phosphorescent dopant and JHK6-3 with carbazole and electron transporting group as host and also as the interfacial layer, resulting in drastic increase in quantum efficiency.

• Proceedings of the KIEE Conference
• /
• 1997.07d
• /
• pp.1563-1565
• /
• 1997

Electroluminescence(EL)devices based on organic thin layers have attracted lot of interests because of their possible application as large-area light-emitting display. One of the problems of such devices is lifetime of the cell, where the degradation of the cell is partially due to the crystalliyzation of organic layers. In large part, this problem can be solved by using a multilayer device structure prepared by vapor deposition technique. In this study, blue lightemitting multilayer organic electroluminescence devices were fabricated using Poly (9-vinyl-carbazole) (PVK) and 2-(4'-tert-butylpheny])-5-(4"-bis-phenyl)1,3,4-oxadiazole (PBD) as hole trasport and electron transport material, respectively, where tris(8-hydroxyquinolinate) aluminum (Alq3) was used as a luminescenct material. A cell structure of glass substrate/indume-tin-oxide(ITO)/PVK/$Alq_3$/PBD/Mg:In was employed.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.1
• /
• pp.27-30
• /
• 2010

A series of thioureas were synthesized as inhibitors of NO production in lipopolysaccharide-activated macrophages. We investigated the effect of lipophilic moiety and N-substituents of the thioureas on the activity. Phenoxazine and carbazole-containing derivatives revealed higher activity than indole-containing thioureas. The appropriate spacer between lipophilic tail and thiourea head and methyl substituent at N3 position of thiourea brought beneficial effect on the inhibition of NO production. Among prepared compounds, phenoxazine-containing derivative 2a was the most potent with $2.32 {\mu}M$ of $IC_{50}$ value. RT-PCR analysis suggested that the prepared thioureas inhibited NO production through the suppression of iNOS mRNA expression.

• Bulletin of the Korean Chemical Society
• /
• v.23 no.4
• /
• pp.571-574
• /
• 2002

The photorefractive polymeric composite with good performance was prepared. The carbazole-substituted polysiloxane sensitized by 2,4,7-trinitro-9-fluorenone was used as a photoconducting medium and 1-[4-(2-nitrovinyl)phenyl]piperidine was added as an optically nonlinear chromophore. The photorefractive property of polymer was determined by diffraction efficiency using a 100 ㎛-thick film. The maximum diffraction efficiency ( ηmax) of 71% was obtained at the electric field of 70 V/ ㎛. The potential of the current polymer material as a holographic recording medium was evaluated by the demonstration of holographic recording and subsequent reading of optical image.

• Journal of the Korean Chemical Society
• /
• v.36 no.4
• /
• pp.603-605
• /
• 1992

N-Substituted pyrroles were synthesized from 1,4-dichloro-1,4-dimethoxybutane and primary amines or amide in the presence of Amberlyst A-21 resin. Further reation of these N-substituted pyrroles with 1,4-dichloro-1,4-dimethoxybutane gave N-substituted carbazoles in moderate yields.

• Bulletin of the Korean Chemical Society
• /
• v.25 no.8
• /
• pp.1202-1206
• /
• 2004

Novel naphthyl-containing biphenyl analogues were prepared by Suzki reaction for the chemiluminescent blue fluorophores. UV-Vis absorption, photoluminescence, chemiluminescence and CIE chromaticities were measured. The fluorophores displayed blue photoluminescence in solution with a maximum intensity around 378-415 nm. Sodium salicylate-catalyzed reaction of them with bis(2 carbopentyloxy-3,5,6-trichlorophenyl)-oxalate with hydrogen peroxide provided a strong chemiluminescent red light emission with wavelengths of 398-427 nm; these were similar to the photoluminescent spectra. The chemiluminescent intensity decayed exponentially and the glow of chemiluminescence, which was visible with naked eyes, was maintained for more than 4 h.