• Corrosion Science and Technology
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• 제4권6호
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• pp.231-235
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• 2005

The inhibitive effect of extracts of tamarind seeds and jackfruit seeds, curry leaves and henna leaves on corrosion of mild steel in 1M HCl solution have been studied by weight loss, potentiodynamic polarization and impedance measurements. Results obtained from the electrochemical techniques were in good agreement with weight loss results. From the weight loss data, the values of surface coverage ($\Theta$) and corrosion rate were calculated. The inhibition efficiency (IE) increased with increasing inhibitor concentration in 1M HCl solution. In all the cases the adsorption of the natural product extracts on the mild steel surface from 1M HCl follows the Langmuir adsorption isotherm relationship. Potentiodynamic polarization studies reveal the fact that all the four natural product extracts act as mixed type inhibitors. The decrease in the inhibition efficiency follows the order: Extracts of jackfruit seed>henna leaves>curry leaves>tamarind seed.

• Bulletin of the Korean Chemical Society
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• 제32권spc8호
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• pp.2883-2884
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• 2011

• 한국미생물·생명공학회지
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• 제24권3호
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• pp.336-343
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• 1996

Maximum amount of the aminopeptidase M inhibitors produced by Streptomyces griseoplanus SL20209 in 500 ml-Erlenmeyer flask was accumulated after cultivation for 3 days at 28$\circ$C, thereafter the amount of inhibitors decreased slowly with a pH change to alkaline. Arabinose, xylose, mannose and soluble starch were good carbon sources for the production of the inhibitors. On the other hand, glucose was only good for the cell growth but potently inhibited the production of inhibitors. Natural organic nitrogen sources such as soybean meal, fish meal, gluten meal and peanut powder were good for the production of inhibitors, however, soytone, peptone and inorganic nitrogens such as NH$_{4}$C1 and NH$_{4}$NO$_{3}$ were poor. Inclusion of yeast extract (0.5%, w/v) or K$_{2}$HPO$_{4}$ (0.05%) into the production medium increased the production of inhibitors by accelerating cell growth. The production of inhibitors was slightly increased on the medium containing CaCO$_{3}$ (0.3%) and zeolite (0.5%), respectively. Optimal temperature and initial pH range for the production ot inhibitors were determined to be 28$\circ$C and 6.0-7.0, respectively. Employing two improved production media consisting of 3% arabinose or soluble starch, 2.5% soybean meal, 0.5% yeast extract, 0.05% K$_{2}$HP0$_{4}$, 0.1% CaCO$_{3}$ and 0.3% zeolite (pH 6.8), 1.8-fold increase in the amount of inhibitors was achieved, comparing with the basal medium used.

• 대한약학회:학술대회논문집
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• 대한약학회 2001년도 Proceedings of International Convention of the Pharmaceutical Society of Korea
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• pp.252.2-253
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• 2001

• BMB Reports
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• 제45권5호
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• pp.299-304
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• 2012

The ubiquitin-proteasome system is a major proteolytic system for nonlysosomal degradation of cellular proteins. Here, we investigated the response of mouse embryonic stem (ES) cells under proteotoxic stress. Proteasome inhibitors induced expression of heat shock protein 70 (HSP70) in a concentration- and time-dependent manner, and also induced apoptosis of ES cells. Importantly, more apoptotic cells were observed in ES cells compared with other somatic cells. To understand this phenomenon, we further investigated the expression of HSP70 and pluripotent cell markers. HSP70 expression was more significantly increased in somatic cells than in ES cells, and expression levels of pluripotent cell markers such as Oct4 and Nanog were decreased in ES cells. These results suggest that higher sensitivity of ES cells to proteotoxic stress may be related with lower capacity of HSP70 expression and decreased pluripotent cell marker expression, which is essential for the survival of ES cells.

• 약학회지
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• 제41권5호
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• pp.565-570
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• 1997

High levels of extracellular phospholipase $A_2$ (Plase $A_2$) associated with inflammatory process in man and animal models have been extensively reported elsew here. Thus, a logical approach to the treatment of inflammatory diseases should involve the inhibitors of Plase $A_2$. To develop new Plase $A_2$ inhibitors from natural products, two hundred crude drugs were screened using group II PLA$A_2$ inhibitory activity. Among them, methanol extract of 5 medicinal plants such as, Raphani Semen, Moutan cortex radicis, Arecae semen, Caryophylli Cortex and Betulae Cortex inhibited more than 90% of PLase $A_2$ activity at a concentration 2.5${\mu}g/ml$. Then, 10 methanol extracts sample were transferred into organic solvents, PLase $A_2$ inhibitory effects were found mainly in CHCl3 and EtoAc fractions.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1998년도 Proceedings of UNESCO-internetwork Cooperative Regional Seminar and Workshop on Bioassay Guided Isolation of Bioactive Substances from Natural Products and Microbial Products
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• pp.183-183
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• 1998

Telomerase synthesizes telomeric DNA repeats onto chromosome ends de novo. Telomerase activation and telomere shortening in human somatic cells have been implicated in cell tumorigenesis and immortalization. In order to find the potential inhibitors against telomerase activitiy which can be used as potential anticancer agents, we screened about 100 kinds of natural products after partition into n-hexane, ethyl acetate and aqueous layers from methanol extracts. The inhibitory effects of these materials against telomerase enzyme activity were tested in 293T cell culture using telomeric repeat amplification protocol(TRAP). The incorporation of $\^$32/P-dGTP into amplified DNA was measured by adsorption to Whatman DE81 paper instead of using TRAP assay for screening the extracts of natural products. Strong effective compounds were not found in this study but DE81 filter spotting method may be a useful model for the screening. Some of the compounds which showed somewhat inhibitory effects had cytotoxic effects also.

• Environmental Analysis Health and Toxicology
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• 제17권3호
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• pp.253-259
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• 2002

The phototoxicity inhibitory activity of 15 natural products having antiinflammatory effect was screened by three in vitro methods: yeast growth inhibition test with Candida albicans, RBC photohemolysis and MTT assay. We induced phototoxic reaction by irradiating UVA (365 nm) on chlorpromazine (CPZ) that has been widely documented as phototoxic agent in clinical and experimental studies and then observed the effects of the natural products after treating them with CPZ. In yeast growth inhibition test, X. stramonium showed the inhibitory effect on the UVA phototoxicity and E. officinalis, Yeast, P. suffruticosa showed phototoxicity inhibitory effect in that their ％ hemolysis compared with control were 36.14${\pm}$ 2.69, 42.82${\pm}$1.35, 36.41${\pm}$0.48 on UVA. In MTT assay, all tested natural products increased cell viability compared with the control.

• 한국식품과학회지
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• 제18권5호
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• pp.339-344
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• 1986

Trypsin inhibitor가 trypsin과 안정한 복합체를 형성하고 동시에 일반 단백질은 trypsin에 의하여 가수분해 되는 원리를 이용하여 trypsin inhibitor를 용이하게 검정 할 수 있는 방법을 고안하였다. trypsin으로 가수분해 시킨 대두추출액을 Sephadex G-50을 이용하여 trypsin-trypsin inhibitor 복합체를 분리시킨 후에 SDS 전기 영동으로 trypsin inhibitor를 복합체를 분리시킨 후에 SDS 전기 영동으로 trypsin inhibitor를 검정할 수 있었다. 이들 trypsin inhibitor는 trypsin에 의한 2차 가수분해에서도 가수분해 되지 않았으며, 또한 2차원 전기영동과 DEAE-Sephades A-25크로마토 그래피를 이용하여 trypsin inhibitor가 trypsin과 복합체를 형성하는 능력을 검정함으로써 본 방법의 유효성을 확인하였다. 본 실험 방법으로 대두(Hill 품종)의 trypsin inhibitor를 검정한 결과 7개의 trypsin inhibitor를 찾아 낼 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제28권10호
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• pp.1824-1826
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• 2007