• Title/Summary/Keyword: Quinoxaline

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Synthesis of Some Quinoxaline Derivatives Containing Indoline-2,3-dione or Thiazolidinone Residue as Potential Antimicrobial Agents

  • Gendy, Adel-A. El;Meligie, Salwa-El;Afaf-K. El-Ansary;Aly-M. Anmedy
    • Archives of Pharmacal Research
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    • v.18 no.1
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    • pp.44-47
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    • 1995
  • The synthesis of osme quinoxaline derivatives containing indoline-2, 3-dione or thiazolidlinone residue is described. The synthesized derivatives were sureened in vitro for their growth inhibitory activity against six species of bacteria, viz. Staphylococcus aureus, Streptococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Serratia marcescens and Mycobacterium semegmatils. Most of the compounds exhibited antimicrobial activity especially those having indoline-2, 3-dione moiety.

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DFT and Time-dependant DFT Investigation of eLectronic Structure, Phosphorescence and Electroluminescence Properties of Iridium (III) Quinoxaline Complexes (Iridium (III) quinoxaline 착물의 전자 구조, 인광 및 전기 발광 특성에 대한 DFT 및 시간-의존 DFT 연구)

  • Zhou, Xiao-Qing;Li, Ying;Sun, Yan-Bo;Zhang, Hong-Xing
    • Journal of the Korean Chemical Society
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    • v.55 no.3
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    • pp.354-363
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    • 2011
  • Quantum-chemistry study was explored to investigate the electronic structures, absorption and phosphorescence mechanism, as well as electroluminescence (EL) properties of three red-emitting Ir(III) complexes, $(fpmqx)_2Ir$(L) {fpmqx=2-(4-fluorophenyl)-3-methyl-quinoxaline; L=triazolylpyridine (trz) (1); L=picolinate (pic) (2) and L=acetylacetonate (acac) (3)}. The calculated results show that the HOMO distribution for 1 is mainly localized on trz moiety due to its stronger ${\pi}$-electron acceptor ability, and HOMO for 2 and 3 is the combination of Ir d- and phenyl ring ${\pi}$-orbital. The higher phosphorescence yields and differences among 1-3 are investigated in this paper. In addition, the reasons of higher EL efficiency of 2 than 1 and 3 have been rationalized.

Highly Efficient Red Emissive Heteroleptic Cyclometalated Iridium(III) Complexes Bearing Two Substituted 2-Phenylquinoxaline and One 2-Pyrazinecarboxylic Acid

  • Sengottuvelan, Nallathambi;Yun, Seong-Jae;Kim, Dae-Young;Hwang, In-Hye;Kang, Sung Kwon;Kim, Young-Inn
    • Bulletin of the Korean Chemical Society
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    • v.34 no.1
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    • pp.167-173
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    • 2013
  • A series of highly efficient red phosphorescent heteroleptic iridium(III) complexes 1-6 containing two cyclometalating 2-(2,4-substitued phenyl)quinoxaline ligands and one chromophoric ancillary ligand were synthesized: (pqx)$_2Ir$(mprz) (1), (dmpqx)$_2Ir$(mprz) (2), (dfpqx)$_2Ir$(mprz) (3), (pqx)$_2Ir$(prz) (4), (dmpqx)$_2Ir$(prz) (5), (dfpqx)$_2Ir$(prz) (6), where pqx = 2-phenylquinoxaline, dfpqx = 2-(2,4-diflourophenyl)quinoxaline, dmpqx = 2-(2,4-dimethoxyphenyl)quinoxaline, prz = 2-pyrazinecarboxylate and mprz = 5-methyl-2-pyrazinecarboxylate. The absorption, emission, electrochemical and thermal properties of the complexes were evaluated for potential applications to organic light-emitting diodes (OLEDs). The structure of complex 2 was also determined by single-crystal X-ray diffraction analysis. Complex 2 exhibited distorted octahedral geometry around the iridium metal ion, for which 2-(2,4-dimethoxyphenyl)quinoxaline N atoms and C atoms of orthometalated phenyl groups are located at the mutual trans and cis-positions, respectively. The emission spectra of the complexes are governed largely by the nature of the cyclometalating ligand, and the phosphorescent peak wavelengths can be tuned from 588 to 630 nm with high quantum efficiencies of 0.64 to 0.86. Cyclic voltammetry revealed irreversible metal-centered oxidation with potentials in the range of 1.16 to 1.89 V as well as two quasi-reversible reduction waves with potentials ranging from -0.94 to -1.54 V due to the sequential addition of two electrons to the more electron-accepting heterocyclic portion of two distinctive cyclometalated C^N ligands.

Modifying Action of Chitosan Oligosaccharide on 2-Amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx)-induced Mutagenesis

  • Shon, Yun-Hee;Ha, Young-Min;Jeong, Teuk-Rae;Kim, Cheorl-Ho;Nam, Kyung-Soo
    • BMB Reports
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    • v.34 no.1
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    • pp.90-94
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    • 2001
  • The mutagenic activity of chitosan oligosaccharide and its antimutagenic effect against 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) were investigated using the Salmonella/Ames test. No mutagenic activity was found in the Salmonella typhimurium strains TA 98 and TA 100, either with or without S9 activation. In contrast, chitosan oligosaccharide showed an inhibitory effect on the mutagenic activity of the cooked food mutagen, MeIQx, in the presence of S9. The influence of chitosan oligosaccharide on the genotoxicity of MeIQx was examined using a host-mediated assay in mice. The oligosaccharide was administered for 14 consecutive days (intragastric application at doses of 0.1 or 0.5 g/kg body wt) to mice. S. typhimurium TA 98 was given intravenously before an oral dose of MeIQx (4.5 mg/kg body wt.). The number of $his^+$ revertants were determined from the Ever of mice. The intragastric application of oligosaccharide led to a 47% reduction in the number of mutants induced by MeIQx (p<0.05). These results suggested that chitosan oligosaccharide had antimutagenic properties against MeIQx in vitro and in vivo.

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Antimutagenic Effect of Polysaccharides Extracted from Soybeans Fermented with Basidiomycetes on 2-Amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx)

  • Shon, Yun-Hee;Kim, So-Yeun;Lee, Jae-Sung;Lim, Jong-Kook;Nam, Kyung-Soo
    • Journal of Microbiology and Biotechnology
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    • v.11 no.2
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    • pp.346-349
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    • 2001
  • The antimutagenic activity of polysaccharides extracted from soybeans fermented with Agrocybe cylindracea (AC) or Phellinus igniarius (PI) against 2-amino-3,8-dimethylimidaxo[4,5-f]quinoxaline (MeIQx) was examined using a Salmonella/Ames test and host-mediated assay in mice. The polysaccharides from the soybeans fermented with A. Cylindracea and P. igniarius inhibited the mutagenic acitivity of the cooked food mutagen, MeIQx, by 31.2% and 35.3%, respectively. The polysaccharides also inhibited MeIQx genotoxicity in a dose-dependent manner in micel. These results suggest that the polysaccharides from soybeans fermented with A. cylindracea or P. igniarius exhibit antimutagenic properties against MeIQx in vitro and in vivo.

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Synthesis of New 2,4-Disubstituted Thiazoles and 2-(Allylidenehydrazono)-thiazolo[5,4-b]quinoxaline Derivatives (새로운 2,4-이치환된 티아졸들과 2-(Allylidenehydrazono)-thiazolo[5,4-b]quinoxaline 유도체들의 합성)

  • Kim, Jong-Geun;Bae, Sun Kun
    • Applied Chemistry for Engineering
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    • v.20 no.2
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    • pp.134-139
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    • 2009
  • A series of allylidenethiosemicarbazone compounds (2a~2e) were obtained in 45~85% by condensing (E)-3-(aryl)acrylaldehyde (1a~1e) with thiosemicarbazide. Theses compounds on treatment of 2,4'-dibromoacetophenone and 2,3-dichloroquinoxaline yielded 2,4-disubstituted thiazoles (3a~3e) and 2-[(E)-3-(aryl)allylidenehydrazono]thiazolo[5,4-b]quinoxaline (4a~4e) in good yield respectively. The structures of all the newly synthesized compounds were identified by IR and $^1H-NMR$ spectral data.

Improved Solubility and Characterization of Photovoltaic Properties D/A Copolymers based on Rigid Structure of Phenothiazine-Quinoxaline (Rigid한 Phenothiazine-Quinoxaline D/A 공액 고분자 구조의 용해성 향상 연구 및 유기박막태양전지로의 특성 분석)

  • Seong, Ki-Ho;Yun, Dae-Hee;Park, Yong-Sung
    • Clean Technology
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    • v.20 no.4
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    • pp.415-424
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    • 2014
  • In this study, two kinds of polymer (PPQX-2hdPTZ (P1), POPQX-2hdPTZ (P2)) were synthesised by Suzuki coupling reaction based on phenothiazine derivative as electron-donor and quinoxaline derivative as electron-acceptor. Microwave synthesis workstation was used to shorten the polymerization time and increase the degree of polymerization. The physical, thermal stability, optical and electrochemical properties of the synthesized polymer were confirmed. The thermal stability of two polymers was outstanding as the initial decomposition temperature was $323-328^{\circ}C$. And additional substituted alkoxy chain on P2 showed higher degree of polymerization. An analysis of electrochemical properties, all polymer had similar HOMO energy level values. Device was fabricated by ITO/PEDOT:PSS/active layer/$BaF_2$/Al structure and photovoltaic properties were confirmed. Each device has a different film thickness and the resulting change in PCE was confirmed. As a result the thinner thickness of the film showed a high efficiency ($PCE_{max}:P1=1.0%$, P2 = 1.1%).

Synthesis of Novel Pyrazolylquinoxalines (새로운 Pyrazolylquinoxaline류의 합성)

  • Kim, Ho Sik;Kwag, Sam Tag
    • Journal of the Korean Chemical Society
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    • v.44 no.3
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    • pp.229-236
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    • 2000
  • The reaction of 6-chloro-2-hydrazinoquinoxaline 4.oxide(10) with acetylacetone or dibenzoylmethane gave 6-chloro-2-(3,5-disubstituted pyrazol-1-yl)quinoxaline 4-oxides (11) through the intramolecular·cyclization.The chlorination of compound 11 with phosphoryl chloride afforded 3,6-dichloro-2-(3,5-disubstituted pyrazol-1-yl)quinoxalines (12), whose reaction with hydrazine hydrate provided 6-chloro-3-hydrazinodehydes, benzenesulfonyl chloride, substituted benzoyl chlohdes or acyl chlorides gave novel pyrazolylquinoxalines (14-17).

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Influence of Food Ingredients on the Formation of Heterocyclic Aromatic Amine in Cooked Pork Patties

  • Shin, Han-Seung
    • Food Science and Biotechnology
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    • v.14 no.5
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    • pp.572-575
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    • 2005
  • The effects of cooking method, cooking time and various food ingredients on the formation/ inhibition of heterocyclic aromatic amines (HAAs) in pork products were investigated. Three HAAs, 2-amino-3,8-dimethylimidazo [4,5-f] quinoxaline ($MeIQ_x$), 2-amino-3,4,8-trimethylimidazo [4,5-f] quinoxaline ($DiMeIQ_x$) and 2-amino-1-methyl-6-phenylimidazo [4,5-b] pyridine (PhIP) were measured in pork products using solid-phase extraction and HPLC. Pork patties were boiled, oven-broiled and pan-fried to internal temperatures of 71, 77 and $88^{\circ}C$. Generally, HAA concentrations increased with increasing internal temperature, and HAA formation was greatest with pan-fried. Selected food ingredients (vitamin E, sodium nitrite, sodium tripolyphosphate, sodium ascorbate, Nanking cherry tissue and cherry tissue extract) inhibited HAA formation in pork patties fried at $225^{\circ}C$ for 10 min/side, with the greater inhibition provided by cherry tissue and its methanolic extract.