• Title/Summary/Keyword: Heterocyclic

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Application of surface modified sericite to remove anionic dye from an aqueous solution

  • Choi, Hee-Jeong
    • Environmental Engineering Research
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    • v.22 no.3
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    • pp.312-319
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    • 2017
  • The treatment of dyeing wastewater is not easy because dyes are mainly aromatic, heterocyclic compounds. The most effective technologies and methods to treat dyeing wastewater are costly and involve materials that are difficult to regenerate after use. Therefore, it is necessary to develop cost-effective, eco-friendly technologies to treat dyeing wastewater. The aim of this study was to investigate the removal of sulfur blue 11 (CI 53235) anionic dye using methyl esterified sericite (ME-sericite) adsorbents in an aqueous solution. The results are discussed in terms of the ME-sericite particle size, temperature, pH value and initial sorption rate according to the initial sulfur blue concentration. In addition, we analyzed the adsorption kinetics using a Pseudo-second-order model with the desorption and reusability. The methyl esterification caused a considerable increase in the specific surface area from 4.45 to $17.62m^2/g$. The ME-sericite adsorbents successfully removed > 98% of the sulfur dye in the aqueous solution. For the adsorption of 1 mg of sulfur dye, approximately 4.6 to 6.6 g/L ME-sericite were required. The desorption process was carried out by mixing a NaOH eluent to desorb 90.56% of the sulfur dye with 2 h of contact time. Thus, the ME-sericite is a promising adsorbent to treat dyeing wastewater due to its low dose requirement, high removal efficiency and inexpensive material.

Cruciferous Vegetables: Dietary Phytochemicals for Cancer Prevention

  • Abdull Razis, Ahmad Faizal;Noor, Noramaliza Mohd
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.3
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    • pp.1565-1570
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    • 2013
  • Relationships between diet and health have attracted attention for centuries; but links between diet and cancer have been a focus only in recent decades. The consumption of diet-containing carcinogens, including polycyclic aromatic hydrocarbons and heterocyclic amines is most closely correlated with increasing cancer risk. Epidemiological evidence strongly suggests that consumption of dietary phytochemicals found in vegetables and fruit can decrease cancer incidence. Among the various vegetables, broccoli and other cruciferous species appear most closely associated with reduced cancer risk in organs such as the colorectum, lung, prostate and breast. The protecting effects against cancer risk have been attributed, at least partly, due to their comparatively high amounts of glucosinolates, which differentiate them from other vegetables. Glucosinolates, a class of sulphur-containing glycosides, present at substantial amounts in cruciferous vegetables, and their breakdown products such as the isothiocyanates, are believed to be responsible for their health benefits. However, the underlying mechanisms responsible for the chemopreventive effect of these compounds are likely to be manifold, possibly concerning very complex interactions, and thus difficult to fully understand. Therefore, this article provides a brief overview about the mechanism of such compounds involved in modulation of carcinogen metabolising enzyme systems.

Keratinocyte모델에서 발암성 이환방향족아민의 종(species)간 독성 감수성

  • Jeon, Hyang-Suk
    • Bulletin of Food Technology
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    • v.12 no.2
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    • pp.26-38
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    • 1999
  • 조리가공 중 생성되는 주요 발암성 이환방향족아민(heterocyclic aromatic amine)인 Trp-P-1 및 Trp-P-2가 human 및 rat keratinocytes에 대해 나타내는 세포 독성을 colony expansion법의 의해 조사, 비교하였다. 특히 Trp-P-2는 human keratinocytes에 대해서는 독성을 나타내지 않은데 반해 rat keratinocytes(계대수 2-5)에 대해서는 독성을 나타내는 선택성을 나타내었다. 이러한 Trp-P-2의 종(species)간 독성감수성 차이가 대사 효소계 활성이나 mutagenic activation상의 차이에 기인되는지를 살펴본 결과, CYP4501As 및 독성감수성 차이가 크게 나타났던 human 및 rat keratinocytes의 microsome에서 거의 같았다. 이와 같은 결과는 CYP4501A1 및 CYP1B1의 mRNA의 발현정도를 northernblot에 의해 살펴보았던 결과에서도 일치하였다. 반면 Trp-P-2의 대사활성화 및 해독화에 관여하는 효소인 N.O-acetyltransferase(NAT)활성은 rat keratinocytes보다 human keratinocytes에서 높았다. 일반적으로 독성물질의 해독화에 관여하는 glutathione S-transferase(GST) 또한 rat keratinocytes보다 human keratinocytes에서 높게 나타났다. Trp-P-2가 mutagenic metabolite로 활성화되는 정도를 salmonella microsome microsuspension assay로 살펴본 결과, 독성 감수성 차이가 크게 나타났던 human 및 rat keratinocytes간의 활성은 비슷한 것으로 나타났다. DNA 및 단백질 adduct형성능의 경우, human 및 rat keratinocytes간 DNA adduct형성능에는 차이가 없었고, 단백질 adduct형성능의 경우만 Trp-P-2에 대한 독성감수성 정도가 컸던 rat keratinocytes가 다른 세포들에 비해 크게 나타났다. 이상의 결과를 종합해 볼 때, CYP1A- 또는 CYP1B1-관련 마이크로솜 효소활성이나 mutagenic activation은 human 및 rat keratinocytes간에 나타났던 독성 감수성의 차이를 설명할 수 없으며, 해독화에 관여하는 효소활성이 종간 관찰되었던 독성 감수성의 차이에 더 중요한 역할을 하는 것으로 보인다.

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Expression of Recombinant Human Cytochrome P450 1A2 in Escherichia coli Bacterial Mutagenicity Tester Strain

  • Chun, Young-Jin
    • Archives of Pharmacal Research
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    • v.21 no.3
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    • pp.305-309
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    • 1998
  • Human cytochrome P450 1A2 is one of the major cytochrome P450s in human liver. It is known to be capable of activating a number of carcinogens such as arylamines and heterocyclic amines. In order to develop the new bacterial mutagenicity test system with human P450, a full length of human P450 1A2 cDNA inserted into pCW bacterial expression vector was introduced to Escherichia coli WP2 uvrA strain which is a well-known E. coli strain for bacterial reverse mutagenicity assay. Expressed human P450 1A2 showed typical P450 hemoprotein spectra. Maximum expression was achieved at 48 hrs after incubating at $30^{\circ}C$ in terrific broth containing ampicillin, IPTG and other supplements. High level expression of P450 1A2 in E. coli WP2 uvrA membranes was determined in SDS-PAGE. The well-known mutagens 2-aminoanthracene and MElQ increased the revertant colonies of E. coli WP2 uvrA expressing human P450 1A2 without an exogenous rat hepatic post-mitochondrial supernatant (S9 fraction) in a dose-dependent manner. The results show that the functional expression of human P450 in bacterial mutagenicity tester strain will provide a useful tool for studying the mechanism of the mutagenesis and carcinogenesis of new drugs and environmental chemicals.

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Synthesis of Substituted Pyridine-2, 4-dione Nucleosides

  • Joon, Joon-Kwang;Won, Jeong-Hee;Park, Jung-Sup;Hwang, Chang-Ho;Chung, K.H.;Ryu, Eung K.
    • Archives of Pharmacal Research
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    • v.15 no.1
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    • pp.87-90
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    • 1992
  • The syntheses of novel heterocyclic base modified pyrimidine nucleosides are described. 5, 6-dimethyl-4-hydroxy-3-methoxy-1-$(\beta$-D-ribofuranosyl)2(1H)-pyridinone 7 was synthesized by condensation of silylated 5, 6-dimethyl4-hydroxy-3-methoxy-2(1H)-pyridione 7 was synthesized by condensation of silylated 5, 6-dimethyl-4-hydroxy-3-methoxy-2(1H)-pyridinone with $\beta$-D-ribofuranose-1-acetate-2, 3, 5-tribenzoate in dichloroethane in the presence of Lewis acid followed by debenzoylation. The 2, 2'-anhydro-5, 6-dimethyl-2-hydroxy-3-methoxy-1-$\beta$-D-arabinofuranosyl-4-pyridinone 8 was obtained from the reaction of the free ribonucleoside 7 and diphenyl carbonate in DMF. None of these compounds showed any significant antiviral ad antitumor activities in vitro tests.

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Evaluation of Anticancer Activity of Curcumin Analogues Bearing a Heterocyclic Nucleus

  • Ahsan, Mohamed Jawed
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.4
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    • pp.1739-1744
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    • 2016
  • We report herein an in vitro anticancer evaluation of a series of seven curcumin analogues (3a-g). The National Cancer Institute (NCI US) Protocol was followed and all the compounds were evaluated for their anticancer activity on nine different panels (leukemia, non small cell lung cancer, colon cancer, CNS cancer, melanoma, ovarian cancer, renal cancer, prostate cancer and breast cancer) represented by 60 NCI human cancer cell lines. All the compounds showed significant anticancer activity in one dose assay (drug concentration $10{\mu}M$) and hence were evaluated further in five dose assays (0.01, 0.1, 1, 10 and $100{\mu}M$) and three dose related parameters $GI_{50}$, TGI and $LC_{50}$ were calculated for each (3a-g) in micro molar drug concentrations (${\mu}M$). The compound 3d (NSC 757927) showed maximum mean percent growth inhibition (PGI) of 112.2%, while compound 3g (NSC 763374) showed less mean PGI of 40.1% in the one dose assay. The maximum anticancer activity was observed with the SR (leukemia) cell line with a $GI_{50}$ of $0.03{\mu}M$. The calculated average sensitivity of all cell lines of a particular subpanel toward the test agent showed that all the curcumin analogues showed maximum activity on leukemia cell lines with $GI_{50}$ values between 0.23 and $2.67{\mu}M$.

Extractions of Chlorophyll from Spinach and Mate Powders and Their Dyeability on Fabrics (시금치와 마테 분말을 이용한 클로로필 추출과 직물 염색)

  • Yoo, Hye Ja;Ahn, Cheunsoon;Narantuya, Lkhagva
    • Journal of the Korean Society of Clothing and Textiles
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    • v.37 no.3
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    • pp.413-423
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    • 2013
  • Chlorophyll is an abundant pigment found in all green plants, algae, and cyanobacteria. This study uses methanol, acetone and water to extract spinach and mate powders in order to examine the possibility of dyeing animal fibers with chlorophyll without chemical alteration. It was shown that methanol extracts of spinach and mate powders can be effectively used to dye wool and silk fabrics if the extract is mixed with water by methanol:water 65:35 v/v. Compared to methanol extract, the acetone extract showed lower chlorophyll yield and lower dye uptake. Water was not an appropriate solvent for chlorophyll extraction and dyeing. Spinach powder showed a higher dye uptake than mate powder due to the higher chlorophyll content than mate powder. It is possible that the chlorophyll dyeing of wool and silk fabrics is due to the hydrogen bonding between the hydroxy amino acids in fiber and the carbonyl groups of chlorophyll. These carbonyl groups are on the heterocyclic ring and the methyl and ethyl side chains of chlorophyll.

Impact of High Temperature on the Maillard Reaction between Ribose and Cysteine in Supercritical Carbon Dioxide

  • Xu, Honggao;He, Wenhao;Liu, Xuan;Gao, Yanxiang
    • Food Science and Biotechnology
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    • v.18 no.1
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    • pp.66-72
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    • 2009
  • An aqueous ribose-cysteine model system (initial pH 5.6) was conventionally heated to the same browning at varying temperatures ($120-180^{\circ}C$), supercritical carbon dioxide (SC-$CO_2$, 20 MPa) was also applied on the same matrices for same periods at each temperature and about 20% reduction of the absorbance at 420 nm was observed as compared with sole thermal treatment. The headspace volatiles from Maillard reaction mixtures were analyzed by solid-phase microextraction (SPME) in combination with gas chromatography and mass spectrometry (GC-MS), and predominated with sulfur containing compounds, such as thienothiophenes, polysulfur alicyclics, thiols, and disulfides. Reaction temperature exhibited complex effects on volatiles formation and those effects became further complicated by the SC-$CO_2$ treatment. The formation of noncarbonyl polysulfur heterocyclic compounds and thienothiophenes was generally favored at high temperatures. Most volatiles were inhibited in SC-$CO_2$ as compared with thermal treatment alone, however, the well-known meaty aromatic compounds, such as thiols and disulfides, were obviously enhanced.

High Performance Polyimides for Applications in Microelectronics and Flat Panel Displays

  • Ree Moonhor
    • Macromolecular Research
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    • v.14 no.1
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    • pp.1-33
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    • 2006
  • Polyimides (PIs) exhibit excellent thermal stability, mechanical, dielectric, and chemical resistance properties due to their heterocyclic imide rings and aromatic rings on the backbone. Due to these advantageous properties, PIs have found diverse applications in industry. Most PIs are insoluble because of the nature of the high chemical resistance. Thus, they are generally used as a soluble precursor polymer, which forms complexes with solvent molecules, and then finally converts to the corresponding polyimides via imidization reaction. This complexation with solvent has caused severe difficulty in the characterization of the precursor polymers. However, significant progress has recently been made on the detailed characterization of PI precursors and their imidization reaction. On the other hand, much research effort has been exerted to reduce the dielectric constant of PIs, as demanded in the microelectronics industry, through chemical modifications, as well as to develop high performance, light-emitting PIs and liquid crystal (LC) alignment layer PIs with both rubbing and rubbing-free processibility, which are desired in the flat-panel display industry. This article reviews this recent research progresses in characterizing PIs and their precursors and in developing low dielectric constant, light-emitting, and LC alignment layer PIs.

Antigenotoxicity of Vegetable or Fruit Extract against Cigarette Smoke Condensate (담배연기응축물의 DNA 손상작용과 야채 및 과일추출물의 보호효과)

  • Lee, Hyeong-Ju;Heo, Chan;Kim, Nam-Yee;Heo, Moon-Young
    • YAKHAK HOEJI
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    • v.55 no.3
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    • pp.251-259
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    • 2011
  • Cigarette smoke condensate (CSC) is known to be carcinogenic compound. CSC contains many organic compounds such as polycyclic aromatic hydrocarbons (PAHs), and heterocyclic amine compounds (HCAs). Reactive oxygen species (ROS) are also generated and induce oxidative DNA damage during the metabolism of CSC. The rat microsome mediated and DNA repair enzyme treated comet assays together with conventional comet assay were performed to evaluate the mechanisms of CSC genotoxicity. The organic extract of CSC induced oxidative and microsome mediated DNA damage. Vitamin C as a model antioxidant reduced DNA damage in endonuclease III treated comet assay. One of flavonoid, galangin as a CYP1A1 inhibitor, reduced DNA damage in the presence of S-9 mixture. The ethanol extracts of the mixed vegetables (BV) or the mixed fruits (BF) showed potent inhibitory effects against CSC induced DNA damage with oxidative DNA lesions and in the prescence of S-9 mixture. These results indicate that BV and BF could prevent CSC-induced cellular DNA damage by inhibiting oxidative stress and suppressing cytochrome P450 in mammalian cells.