• 제목/요약/키워드: Antibacterial agent

검색결과 339건 처리시간 0.03초

새로운 5-Fluorobenzimidazole 항진균제의 합성과 생물학적 평가 (Synthesis and Biological Valutaion of New 5-Fluorobenzimidazole Antifungal Agents)

  • 류성렬
    • 한국응용과학기술학회지
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    • 제28권1호
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    • pp.118-125
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    • 2011
  • New type of 5-fluorobenzimidazole derivatives was synthesized through the reaction of 4-fluoro-5-(2,6-dimethylmorpholinyl)-2-aminoaniline with 5-nitro-2-furoic acid and 5-methoxy-3-chlorobenzothiophene-2-carboxylic acid in presence of PPA and treatment of $OH^-$. the resulting substituted 5-fluorobenzimidazole derivatives(6), (7) was characterized by high solubility in common polar organic solvents. We considered 5-fluorobenzimidazole derivatives were useful especially for antifungal drugs. These results are discussed from the viewpoints of the chemical and physical structures of the 5-fluorobenzimidazole derivatives.

Lycopene-Induced Hydroxyl Radical Causes Oxidative DNA Damage in Escherichia coli

  • Lee, Wonyoung;Lee, Dong Gun
    • Journal of Microbiology and Biotechnology
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    • 제24권9호
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    • pp.1232-1237
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    • 2014
  • Lycopene, which is a well-known red carotenoid pigment, has been drawing scientific interest because of its potential biological functions. The current study reports that lycopene acts as a bactericidal agent by inducing reactive oxygen species (ROS)-mediated DNA damage in Escherichia coli. Lycopene treatment elevated the level of ROS-in particular, hydroxyl radicals ($^*OH$)-which can damage DNA in E. coli. Lycopene-induced DNA damage in bacteria was confirmed and we also observed cell filamentation caused by cell division arrest, an indirect marker of the DNA damage repair system, in lycopene-treated E. coli. Increased RecA expression was observed, indicating activation of the DNA repair system (SOS response). To summarize, lycopene exerts its antibacterial effects by inducing $^*OH$-mediated DNA damage that cannot be ameliorated by the SOS response. Lycopene may be a clinically useful adjuvant for current antimicrobial therapies.

비자 추출물의 식품부패균에 대한 항균효과 및 항산화활성 (Antimicrobial Effects on Food-Borne Pathogens and the Antioxidant Activity of Torreya Nucifera Extract)

  • 임태진;최무영
    • 한국지역사회생활과학회지
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    • 제26권4호
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    • pp.697-705
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    • 2015
  • This study investigates antimicrobial effects of food-borne pathogens and the antioxidant activity of Torreya nucifera extract. The growth of food-borne pathogens including Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans was inhibited by the extract. The antimicrobial activity of the extract was highest for Staphylococcus aureus among seven gram-positive bacteria and for Pseudomonas aeruginosa among six gram-negative bacteria. The extract exhibited slightly lower DPPH radical-scavenging activity, but its ABTS radical-scavenging activity was higher than that of ${\alpha}$-tocopherol. The results demonstrate the extract's antimicrobial effects on food-borne pathogens as well as potent antioxidant capacity and suggest that Torreya nucifera may be used as a natural antibacterial agent and an effective antioxidant in food.

Photocleavage of DNA by 4′-Bromoacetophenone- Pyrrole Carboxamides

  • Jeon, Raok
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 2001년도 추계학술대회 및 정기총회
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    • pp.79-79
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    • 2001
  • Genotoxic chemotherapeutics are irreversible DNA targeting agents, which can act as anticancer and antiviral drugs. Natural antibacterial and anticancer enediynes function through the formation of free radicals formed by Bergman-type cycloaromatization and being capable of cleavage of DNA strand. They have been focused primarily on the design and syntheses of simple enediyne structures, which can be mimic their mechanistic feature. Recently. I have been reported the possible application of 4'-bromoacetophenone as a simple photoactivatable DNA cleaving agent, which could be readily prepared and exhibit potent and selective DNA cleaving activity. Herein, we further investigated the activity of 4'-bromoacetophenone-pyrrolecarboxamides, which consist of both DNA cleaving element and recognition unit under various conditions in order to get more understanding of the mechanism of the action and find a broad spectrum of application.

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Dual Effect of the Cubic Ag3PO4 Crystal on Pseudomonas syringae Growth and Plant Immunity

  • Kim, Mi Kyung;Yeo, Byul-Ee;Park, Heonyong;Huh, Young-Duk;Kwon, Chian;Yun, Hye Sup
    • The Plant Pathology Journal
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    • 제32권2호
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    • pp.168-170
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    • 2016
  • We previously found that the antibacterial activity of silver phosphate crystals on Escherichia coli depends on their structure. We here show that the cubic form of silver phosphate crystal (SPC) can also be applied to inhibit the growth of a plant-pathogenic Pseudomonas syringae bacterium. SPC pretreatment resulted in reduced in planta multiplication of P. syringae. Induced expression of a plant defense marker gene PR1 by SPC alone is suggestive of its additional plant immunity-stimulating activity. Since SPC can simultaneously inhibit P. syringae growth and induce plant defense responses, it might be used as a more effective plant disease-controlling agent.

파라퀴논 유도체와의 전하이동착물 형성을 이용한 에녹사신 정량 (The Determination of Enoxacin with p-Quinone Derivatives)

  • 이지연;김동오;남수자;정문모;허문회;안문규
    • 약학회지
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    • 제43권4호
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    • pp.437-441
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    • 1999
  • Enoxacin[1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-\piperazinyl)-1,8-naphthyridine-3-carboxylic acid, ENX] is a new quinolone antibacterial agent. The method is based on the highly colored charge-transfer complex formation of this drug as a $\pi$-electron donor with 7,7,8,8-tetracyanoquinodimethane(TCNQ) or chloranil(CL) as $\pi$-acceptors. The colored products were measured spectrophotometrically at 842 nm and 552 nm for TCNQ and CL, respectively. The different experimental conditions are optimized. The linearities for TCNQ and CL were $1.6{\;}\mu\textrm{g}/mL~32{\;}\mu\textrm{g}/mL$ and $6.4{\;}\mu\textrm{g}/mL~160{\;}\mu\textrm{g}/mL$, respectively and colors were produced in non-aqueous media. This report describes a simple and ra\pid method for the analysis of enoxacin.

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Preparation and Characterization of Enrofloxacin/Carbopol Complex in Aqueous Solution

  • Chun, Myung-Kwan;Choi, Hoo-Kyun
    • Archives of Pharmacal Research
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    • 제27권6호
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    • pp.670-675
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    • 2004
  • Since the bitter taste of enrofloxacin apparently limit the patient compliance in the oral formulations of the antibacterial agent, the masking of the taste is essential for the improvement of the therapeutic effectiveness. Therefore, this study was carried out to examine the feasibility of taste masking of enrofloxacin by the retardation of its dissolution rate using the formation of complex between the drug and Carbopol. The complexation between Carbopol and enrofloxacin was confirmed by turbidity, UV spectrophotometry, wide angle X-ray diffraction, and differential scanning calorimetry. The enrofloxacin content in the complexes was 34% (Carbo-enrofloxacin complex I) and 57% (Carbo-enrofloxacin complex II) depending on the prepara-tion method. The dissolution rate of enrofloxacin from the complex increased as the pH was reduced. The dissolution rate of enrofloxacin from the Carbo-enrofloxacin complex I was significantly lower than that of the enrofloxacin powder. Therefore, these observations suggest that Carbo-enrofloxacin complex I can be used to mask the taste of enrofloxacin.

정유의 연구동향(硏究動向)과 향후(向後) 연구전략(硏究戰略)에 대(對)한 고찰(考察) (Study on the research trends and future strategy of essential oil)

  • 김진수;김동희
    • 혜화의학회지
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    • 제9권2호
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    • pp.43-56
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    • 2001
  • 1. All Essential oils have antibacterial properties. 2. Essential oils reduce contamination. 3. Most of essential oils acts as an antofungal, antiviral, antiparasitic, antimicrobial agent and antioxidants. 4. They contain anions, ozone, and oxygenating molecules. 5. It is belueved that they take chemicals and metallices out of the air by breaking the molecular chain. 6. In France, it was reported that various essential oils prevent a side effect of radiation. 7. The essential oils travel via the olfactory nerve stimulating a emotional and phychological response that is believed to be responsible for releasing genetic blue priting from the cells thus releasing emotional trauma.

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TYROSINASE INHIBITORY ACTIVITY OF LONICERA JAPONICA

  • Lai, Jeng-Shiow;Su, Chen-Wen;Huang, Keh-Feng
    • 대한화장품학회:학술대회논문집
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    • 대한화장품학회 2003년도 IFSCC Conference Proceeding Book II
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    • pp.545-547
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    • 2003
  • A tyrosinase inhibitor, Lonjapoin, was isolated from the ethanolic extracts of Flos Lonicera by activity-guided fractionation. Lonjapoin ($IC_{50}$/; 2.07 $\mu\textrm{g}$/mL) was found to be potentially as effective inhibitor of production of melamin. Flos Lonicera (Jinyinhua) is the dry flower buds of Lonicera japonica. Thunb. It is used as an antibacterial and antiphlogistic agent in the treatment of abscess, laryngeal catarrh, erysipelas, dysentery, cold and fever. In our continuing search for natural source as cosmetic ingredients from Chinese medicinal herbs and found the extracts of Flos Lonicera showed the significant tyrosinase inhibition activity. In this study the active constituent of Lonicera japonica. obtained with the process of tyrosinase activity assay and column chromatography.

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항곰팡이성 항생물질의 생산하는 균주의 분리 및 동정 (Isolation and Identification of a Bacterium Producing Antifungal Antibiotic)

  • 신영준
    • 한국식품영양과학회지
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    • 제29권5호
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    • pp.832-836
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    • 2000
  • A bactirium prohibiting the growth of fungus Botrytis cineria KT 433 was isolate and identified from soil. The isolated strain was gram positive, aerobic bacteria with cream color, round and mucoid. It showed ord form of 0.45$\times$1.1 ${\mu}{\textrm}{m}$ at the cultivated for 24 hrs and the ellipsoided endospore wer observed after culting for 72 hrs. The optimum growth temperature and pH wer 35$^{\circ}C$ and pH 5.0~8.0, respectively. It could assimilate daxtrin, maltose, glucose, mannose, ribose and collobiose as a sole carbon source. The isolated was confirmed to be a Bacillus sp. strain from the findings. The antibiotic from the isolated strain was stable up to 121$^{\circ}C$. The strain, especially, showed specific activity for mold and yeast. However, there was not significant antibacterial activity.

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