• 대한화학회지
• /
• 제49권4호
• /
• pp.426-430
• /
• 2005

• Archives of Pharmacal Research
• /
• 제18권1호
• /
• pp.44-47
• /
• 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.

• 대한화학회지
• /
• 제55권3호
• /
• pp.354-363
• /
• 2011

3개의 적색 발광 Ir(III) 착물들인 $(fpmqx)_2Ir$(L) {fpmqx=2-(4-fluorophenyl)-3-methyl-quinoxaline; L=triazolylpyridine (trz) (1); L=picolinate (pic) (2) and L=acetylacetonate (acac) (3)}의 전자 구조, 흡수 및 인광 메커니즘, 전기 발광(EL) 특성을 양자화학적으로 연구하였다. 계산 결과에 따르면, 1의 HOMO는 강한 ${\eth}$-전자 받개 능력을 갖는 trz 부분에 편재되어 있으며, 2와 3의 HOMO는 Ir d-오비탈 과 페닐 고리 ${\pi}$-오비탈의 결합이라는 것을 나타내었다. 이 논문에서는 1-3사이의 인광 수득률과 차이에 대하여 연구하였으며, 1과 3보다 2의 EL 효율이 더 큰 이유를 합리적으로 설명하였다.

• Bulletin of the Korean Chemical Society
• /
• 제34권1호
• /
• pp.167-173
• /
• 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.

• BMB Reports
• /
• 제34권1호
• /
• pp.90-94
• /
• 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.

• Journal of Microbiology and Biotechnology
• /
• 제11권2호
• /
• pp.346-349
• /
• 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.

• 공업화학
• /
• 제20권2호
• /
• pp.134-139
• /
• 2009

(E)-3-(Aryl)acrylaldehyde 유도체들 (1a~1e)과 thiosemicarbazide 축합반응으로 일련의 알릴리덴치오세미카르바존 화합물 (2a~2e)을 45~85%로 얻었다. 이 화합물들을 2,4'-dibromoacetophenone와 2,3-dichloroquinoxaline로 처리하여 각각 2,4-이치환 티아졸류(3a~3e)와 2-[(E)-3-(aryl)allylidenehydrazone]thiazolo[5,4-b]quinoxaline류 (4a~4e)를 좋은 수율로 합성하였다. 새로이 합성한 모든 화합물들의 구조들은 IR과 $^1H-NMR$ 분광학 자료로 확인하였다.

• 청정기술
• /
• 제20권4호
• /
• pp.415-424
• /
• 2014

본 연구는 전자주개 물질인 phenothiazine 유도체와 전자받개 물질로 quinoxaline 유도체를 Suzuki coupling reaction으로 push-pull 구조의 고분자(PPQX-2hdPTZ (P1), POPQX-2hdPTZ (P2))를 합성하였다. 용해도 향상을 위해 기본 골격에 alkoxy 사슬을 도입하였고, 반응시간을 단축시키고 중합도를 높이기 위해 마이크로웨이브 합성 반응기를 이용하여 중합시켰다. 합성된 고분자는 물리적, 열적, 광학적 및 전기화학적 특성을 확인하였다. 두 고분자의 초기분해온도는 $323-328^{\circ}C$로서 열 안정성이 우수함을 확인하였고, 추가로 alkoxy 사슬을 도입한 P2의 중합도가 더 높았다. 전기화학적 특성을 분석한 결과 두 고분자의 HOMO에너지 레벨은 유사하였다. 합성된 고분자는 ITO/PEDOT:PSS/active layer/$BaF_2$/Al 구조로 소자를 제작하여 유기박막태양전지로의 특성을 확인하였다. 각 소자는 박막의 두께를 다르게 하여 이에 따른 효율의 변화를 확인하였고, 박막의 두께가 얇아질수록 높은 효율을 나타내었다($PCE_{max}:P1=1.0%$, P2 = 1.1%).

• 대한화학회지
• /
• 제44권3호
• /
• pp.229-236
• /
• 2000

6-Chloro-2-hydrazinoquinoxaline4-oxide(10)를 아세틸아세톤 또는 디벤조일메탄과 반응시켜 분자내 고리화반응에 의한 6-chloro-2-(3,5-disubstituted pyrazol-1-yl) quinoxaline 4-oxide류(11)를 합성하였다. 화합물 11을 phosphoryl chloride로 염소와 반응시켜 3,6-dichloro-2-(3,5-disubstituted pyrazol-1-yl)quino-xaline류(12)를 합성한 다음 hydrazine hydrate 반응시켜 6-chloro-3-hydrazino-2-(3,5-disubstituted pyrazol-1-yl)quinoxaline류(13)를 합성하였다. 화합물 13을 치환 벤즈알데히드류, benzenesulfonyl chloride, 치환 benzoyl chloride류 및 acyl chlorid 류와 반응시켜 새로운 pyrazolylquinoxaline류(14-17)를 각각 합성하였다.

• Food Science and Biotechnology
• /
• 제14권5호
• /
• pp.572-575
• /
• 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.