• 제목/요약/키워드: inhibition rate

검색결과 1,533건 처리시간 0.029초

Methyl Linoleate Oxidation via Electron Transfer in Competition with $^1O_2$ Formation Photosensitized N-Acetyl-L-Tryptophan 3-Methyl Indole

  • Yoon, Min-Joong;Song, Moon-Young;Cho, Dae-Won
    • Bulletin of the Korean Chemical Society
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    • 제6권5호
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    • pp.291-295
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    • 1985
  • The efficiency of photosensitization of methyl linoleate (ML) oxidation by N-acetyl-L-trypophan(NAT) and 3-methyl indole(scatole) was markedly enhanced by increased concentration of ML in ethanol solution. The fluorescence intensities of sensitizers were observed to be quenched by ML, indicating that ML interacts with the indole excited singlet state. The inhibition of photosensitization by azide demonstrated a possible role of singlet oxygen in the photosensitization. The steady state kinetic treatment of azide inhibition of photosensitization was expected to show linear increase of reciprocal yield of ML oxidation product vs. reciprocal ML concentration at constant azide concentration, but the actual slope was nonlinear. This indicates another competing reaction involved in the photosensitization, As a possible competing reaction, electron transfer from ML to the excited sensitizer was proposed, since the measured fluorescence quenching rate constant closely resembled electron transfer rate constant determined from ML concentration dependence of oxidation product formation.

Enterococcus faecalis 2B4-1 세포벽 성분 중 Polysaccharide Fraction의 종양세포 증식억제 효과 (Growth Inhibition of Polysaccharide Fraction in Cell Wall Components from Enterococcus faecalis 2B4-1 against Tumor Cell Lines)

  • 박상진;김정환;이경호;양종범;백영진;김창한
    • 한국미생물·생명공학회지
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    • 제27권1호
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    • pp.8-14
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    • 1999
  • This study was developed to evaluate the growth inhibition effects of cell wall components of Enterococcus faecalis 2B4-1 obtained from feces of neonates against tumor cell lines. Polysaccharide fraction (PS) shown sensitive growth inhibition effect in the cell wall components was isolated and characterized. In growth inhibition effects, residue fractin of whole cell was shown sensitive level of percent survival about 30% when administrated at ehe concentration of 100${\mu}$g/ml, and that was more effective than that of supernatant fraction against the tumor cell lines, SNU-1, 3LL, FARROW and HEC-1-B. Sensitive growth inhibition effects against SNU-1, FARROW and HEC-1-B were performed by whole cell (WC) fraction from Ent. faecalis 2B4-1. Cytoplasm fractin (CP) of WC was shown non-inhibition effect, however, the other part of WC, precipitate of disrupted cell (PD), was sensitive against the tumor cell line mentioned above. Followed by separation to peptidoglycan fraction (PG) and polysaccharide fraction (PS) were all sensitive which the latter was shown more sensitive percent survival than the former. Composed sugars of polysaccharide fraction were determined to D-glucose, L-rhamnose and D-glucosamine, and the rate fo composition was calculated to about 1:1:1 by the data of elemental analysis, IR, TLC and HPLC.

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UASB 공정에 의한 당밀폐수의 최적처리 방안 (Optimal Treatment of Molasses Wastewater Using UASB Process)

  • 허관용;정의근;정윤진;유상근
    • 상하수도학회지
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    • 제11권2호
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    • pp.112-127
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    • 1997
  • The purpose of this study is to get optimum operating factors of Upflow Anaerobic Sludge Blanket (UASB) reactor by introducing methods that make it to reduce inhibition possible in each process wastewater treatment. The used substrates, concentrated corn starch liquid (CSL) wastewater, modified starch, filtering and decoloring wastewater, ion refining wastewater, and mixed wastewater including modified starch and not including modified starch, are generated from molasses process. The seeding sludge is the digested sludge that had been applied to molasses wastewater. Batch test to reduce the inhibition factors that might be existed in each wastewater was examined. Based on the this test, the optimum operating factors according to alkalinity and pH variation was studied through the continuous test using three 5.5 L UASB reactor. The first reactor added $NaHCO_3$ to control alkalinity. The hydraulic retention time (HRT) reduced to 8 hours and the organic loading rate increased gradually. The second reactor changed the pH of influent from 7.0 to 6.0 using NaOH. The third reactor was operated without changes to compare the above two reactors. As the result, the inhibition in concentrated CSL wastewater was removed by adding iron (II). When trace metals were added to mixed wastewater not including modified starch, the digestability by gas production rate increased to more fifty percentage than mixed wastewater that was not adding the trace metals. The reason that the inhibition did not decreased in spite of adding trace metals and nutrients was influenced by high concentration generated during the acid fermentation. The UASB reactors using the mixed wastewater with the most effective performance were operated as 500 mg/L as $CaCO_3$ alkalinity and 6.0 pH at steady state, and at this time, the gas production rates were 283 and 311mL gas/g $COD_{added}$. The COD removal rates were 84.7 and 86.3%, respectively.

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β-glucosidase 활성 균주 발효에 의한 황기 Isoflavonoid 성분변화 및 생리활성 (The Isoflavonoid Constituents and Biological Active of Astragalus Radix by Fermentation of β-glucosidase Strains)

  • 김철중;최재후;성은수;임정대;최선강;유창연;이재근
    • 한국약용작물학회지
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    • 제28권5호
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    • pp.371-378
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    • 2020
  • Background: In this study, the radix of Astragalus membranaceus Bunge extract fermented by Saccharomyces cerevisiae, Weissella cibaria, and Pediococcus pentosaceus to increase the levels of isoflavonoid aglycone contents. Methods and Results: In order to change the in isoflavonoids, we fermented the radix of A. membranaceus extracts with microorganisms that have β-glucosidase activity. Besed on the β-glucosidase activity, we selected three strains, Weissella cibaria, Pediococcus pentosaceus, and Saccharomyces cerevisiae. HPLC analysis revealed that the levels of isoflavonoid aglycones were increased in all fermentation cases, and the extracts fermented by S. cerevisiae showed the highest levels of isoflavonoid aglycones. We evaluated the antioxidant activity, anti-wrinkle effects and whitening effects of the S. cerevisiae-fermented extracts using the DPPH assay, tyrosinase inhibition activity assay, and collagenase inhibition activity assay. We confirmed higher activity in S. cerevisiae-fermented extracts than in control, with the half maximal inhibitory concentration (IC50) value of 565.1 ± 59.1 ㎍/㎖ in DPPH radical scavenging activity, tyrosinase inhibition rate of 78.4 ± 0.9%, and collagenase inhibition rate of 83.8 ± 1.1%. Conclusions: We selected three stains of microorganisms showing high β-glucosidase activity, W. cibaria, P. pentosaceus and S. cerevisiae. Isoflavonoid glycones in the radix of A. membranaceus were converted to isoflavonoid aglycones by fermentation. In addition, the fermented radix of A. membranaceus exhibited antioxidant activity, anti-wrinkle effect, whitening effect and radical scavenging activity.

볏짚추출물이 독새풀과 보리의 초장 및 유근의 신장에 미치는 영향 (Influence of Rice Straw Extract on Growth of Barley and Water Foxtail(Alopecurus aequalis var. amurensis(Kom.) Ohwi)

  • 이춘우;김용욱;윤의병
    • 한국잡초학회지
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    • 제18권1호
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    • pp.48-53
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    • 1998
  • 노동력 부족으로 대부분의 농가가 논에서 태우거나 볏짚이 있는 상태에서 보리를 파종하고 있으며, 이로 인하여 작물과 잡초의 발생이나 생육이 억제되는 현상이 관찰되고 있다. 이런 현상을 구명하고자, 추출온도, 시간, 추출농도, 생육시기, 품종에 따른 볏짚 추출물이 보리 또는 독새풀의 초장, 근장, 발아율에 미치는 영향을 조사하였다. 1. 볏짚 10%(w/v), $24^{\circ}C$, 5시간 추출액이 보리의 초장, 근장 및 발아를 가장 많이 억제하였다. 2. 5%(w/v)의 볏짚 추출액은 보리의 초장의 신장과 발아를 촉진하나, 독새풀은 억제하였고, 10-20%(w/v)에서 독새풀의 초장, 근장 및 발아율이 61.0-100% 억제되었다. 3. 볏짚의 유묘기, 분얼기, 출수기, 성숙기, 수확기의 추출물중 유묘기의 추출물이 보리의 초장, 근장 및 발아를 가장 많이 억제하였다. 4. 17종의 벼 품종 중 대림벼 추출물이 보리의 생육을 가장 많이 억제하였고, 안중벼가 가장 낮았다. 5 볏짚 추출물에 대하여 10종의 보리품종중 새올보리의 생육이 가장 많이 억제되었고, 부농이 가장 낮았다.

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An investigation of Panax ginseng Meyer growth promotion and the biocontrol potential of antagonistic bacteria against ginseng black spot

  • Sun, Zhuo;Yang, Limin;Zhang, Lianxue;Han, Mei
    • Journal of Ginseng Research
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    • 제42권3호
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    • pp.304-311
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    • 2018
  • Background: Ginseng black spot disease resulting from Alternaria panax Whuetz is a common soil-borne disease, with an annual incidence rate higher than 20-30%. In this study, the bacterial strains with good antagonistic effect against A. panax are screened. Methods: A total of 285 bacterial strains isolated from ginseng rhizosphere soils were screened using the Kirby-Bauer disk diffusion method and the Oxford cup plate assay. We analyzed the antifungal spectrum of SZ-22 by confronting incubation. To evaluate the efficacy of biocontrol against ginseng black spot and for growth promotion by SZ-22, we performed pot experiments in a plastic greenhouse. Taxonomic position of SZ-22 was identified using morphology, physiological, and biochemical characteristics, 16S ribosomal DNA, and gyrB sequences. Results: SZ-22 (which was identified as Brevundimonas terrae) showed the strongest inhibition rate against A. panax, which showed 83.70% inhibition, and it also provided broad-spectrum antifungal effects. The inhibition efficacies of the SZ-22 bacterial suspension against ginseng black spot reached 82.47% inhibition, which is significantly higher than that of the 25% suspension concentrate azoxystrobin fungicide treatment (p < 0.05). Moreover, the SZ-22 bacterial suspension also caused ginseng plant growth promotion as well as root enhancement. Conclusion: Although the results of the outdoor pot-culture method were influenced by the pathogen inoculum density, the cropping history of the field site, and the weather conditions, B. terrae SZ-22 controlled ginseng black spot and promoted ginseng growth successfully. This study provides resource for the biocontrol of ginseng black spot.

멸치액젓으로부터 분리한 Bacillus subtilis JM-3의 생리활성기능에 관한 연구 (Studies on Physiological Activity of Bacillus subtilis JM-3 Isolated from Anchovy Sauce)

  • 이상수;김상무;신일식
    • 한국식품과학회지
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    • 제35권4호
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    • pp.684-689
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    • 2003
  • 속성 발효 및 기능성 멸치액젓의 제조에 사용할 수 있는 미생물 starter의 개발을 목적으로 전보에서 분리한 단백질 분해활성 및 혈전용해활성이 가장 우수했던 B. subtilis JM-3는 저온성 병원성 세균인 Listeria monocytogenes에 대한 항균활성이 가장 강하였으며, linoleic acid의 자동산화를 80%이상 억제하는 항산화활성을 나타내었다. 그리고 N-nitroso compound인 NDMA 및 NMO에 대하여서는 약 50%의 변이억제활성을 나타내었으며, SNU-1(사람의 위암세포)에 대하여 배양 원액 $20\;{\mu}L$를 첨가한 경우 88.9%의 높은 성장 억제율을 나타내어 기능성 멸치액젓 제조용 starter로서의 가능성이 확인되었으며, 앞으로 본 균주의 기능성 멸치액젓 starter로서의 이용을 극대화하기 위하여서는 돌연변이에 의한 호염성 변이주의 유전적 육종이나 형질 전환 방법 등을 응용한 호염성 미생물과의 접목을 통한 내염성 균주의 개발도 필요할 것으로 여겨진다.

Cytotoxic Effects of Partially Purified Substances from Bacillus polyfermenticus SCD Supernatant toward a Variety of Tumor Cell tines

  • Chang, Kyung-Hoon;Park, Jun-Seok;Choi, Jae-Hoon;Kim, Cheon-Jei;Paik, Hyun-Dong
    • Food Science and Biotechnology
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    • 제16권1호
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    • pp.163-166
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    • 2007
  • The cytotoxic effects of partially purified substances from Bacillus polylfermenticus SCD toward a variety tumor cell lines were studied. Cytotoxic activity was determined with regard to the A549 (human lung carcinoma), AGS (human stomach adenocarcinoma), DLD-1 (human colon adenocarcinoma), HEC-1-B (human uterus adenocarcinoma), SW-156 (human kidney carcinoma), and NIH/3T3 (murine normal fibroblast) cell lines using the MTT assay. Cytotoxic substances were partially purified through Diaion HP-20 columns and extracted with methanol or other organic solvents (n-hexane, chloroform, ethylacetate, and butanol). B. polyfermenticus SCD supernatant showed up to 60% inhibition of cell viability fer all five human cancer cell lines tested. When treated with 10 mg/mL of n-hexane, chloroform, ethylacetate, and butanol extract, HEC-1-B cells showed a 25,62,35, and 63% rate of inhibition respectively, and AGS cells showed a 72, 61, 44, and 67% rate of inhibition, respectively. At a concentration of 10 mg/mL, 100% methanol Diaion HP-20 extracts showed inhibition rates of 97.0% toward A-549 cells, 98.1% toward AGS cells, 81.6% toward DLD-1 cells, 83.5% toward HEC-1-B cells, and 92.7% toward SW-156 cells. These results indicate that partially purified fractions from B. polyfermenticus SCD have the potential to inhibit not only colon cancer cells, but also lung, stomach uterus, and kidney cancer cells. Further studies are needed to characterize the cytotoxic substances released in B. polyfermenticus SCD cultures.

Japanese medaka에 있어 Quercetin의 난자성숙 저해에 대한 조직병리학적 연구 (Histopathological Study on Inhibition of Oogenesis by Quercetin in Japanese medaka (Oryzias latipes))

  • 황갑수
    • Environmental Analysis Health and Toxicology
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    • 제14권1_2호
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    • pp.55-63
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    • 1999
  • Endocrine disrupting chemicals probably cause the cytological or/and morphological changes of germinal cells in gonad. Accordingly, this study was aimed to make sure that the effect of hormone-mimicking chemicals on gonad morphology such as decrease of germinal cells, inhibition of cellular maturation and change in the ratio of germinal cells in the different developmental phase can be observed by histopathological procedures and can be a useful bio-indicator for the evaluation of endocrine disruption by environmental chemicals. In this experiment, female Japanese medaka were exposured to quercetin, a phytoestrogen, at the concentration of 100 $\mu\textrm{g}$/L. quercetin showed the significant decrease in the number and rate of vitellogenic follicular oocytes in the treated group for 4 and 6 weeks. The weak development of yolk could be also observed. We could conclude that quercetin has anti-estrogenic or androgen-like potency by exerting the inhibition effect on oogenesis in fish female- gonad. From the result of this study, the applied methods and techniques can be evaluated to be a useful biomonitoring means for water pollution, expecting a good result of the subsequent study on apoptosis.

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Inhibition of Recovery from Potentially Lethal Damage by Chemicals in Chinese Hamster Cells is Realized through the Production of Irreversible Damage

  • Kim Jin Kyu;Komarova Ludmila N.;Tkhabisimova Marianna D.;Petin Vladislav G.
    • 환경생물
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    • 제23권4호
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    • pp.390-397
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    • 2005
  • The inhibition of cell recovery might be proceeded via either the damage of the mechanism of the recovery itself or via the formation of irreversible damage which could not be repaired at all. Both these processes may take place at the same time. Any of these possibilities would result in a decrease in both the rate and extent of cell recovery. To distinguish them, a quantitative approach describing the process of recovery as a decrease in the effective radiation dose was applied to experimental data on the recovery from potentially lethal damage in Chinese hamster cells exposed to X-rays alone or combined with various chemicals (pyruvate, novobiocin, lactate, nalidixic acid, 3-aminobenzamide). For these particular cases, it is concluded that the recovery process itself is not damaged and the inhibition of the recovery is entirely due to the enhanced yield of the irreversibly damaged cells.