• Journal of Microbiology and Biotechnology
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• v.1 no.2
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• pp.85-89
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• 1991

The aim of this study is to elucidate characteristics of ${\beta}-lactamase$ inhibitor produced by Streptomyces sp. SMF-19 isolated from soil was found to produce proteinaceous extracellular ${\beta}-lactamase$ inhibitor. The ${\beta}-lactamase$ inhibitor was purified through ammonium sulfate fractionation, gel filtration, anion exchange chromatography and fast performace liquid chromatography. The molecular weight of the ${\beta}-lactamase$ inhibitor was estimated to be about 48,000 by SDS-PAGE. The mode of inhibition against penicillin G as a substrate was uncompetitive. The ${\beta}-lactamase$ inhibitor was stable in wide pH range but unstable at high temperature above $50^{\circ}C$.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10a
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• pp.195-195
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• 2001

The inhibitory potentials of TCAs (imipramine, desipramine, amitriptyline, and nortriptyline) on phenytoin p-hydroxylation and probe metabolic pathways of each CYP isoforms were evaluated from incubation studies of human liver microsomes and cDNA-expressed cytochrome P450s in vitro in order to understand the mechanism of drug interaction between TCAs and phenytoin, a substrate of CYP2C9 and CYP2C19. (omitted)

• Korean Journal of Medicinal Crop Science
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• v.11 no.4
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• pp.264-267
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• 2003

Korean medicinal plants were screened for their inhibitory activity against HIV-1 protease. The inhibitory activity of protease was determined by incubating the extracts in reaction mixtures containing protease and substrate $His-Lys-Ala-Arg-Val-Leu-(p-NO_{2}-Phe)-Glu-Ala-Nle-Ser-NH_{2}$ to perform proteolytic cleavage reactions. In this study the twenty six extracts from medicinal plants were investigated. Of the extracts tested, the extracts from the stem of Morus alba. exhibited the strongest activity with inhibition of 81% at a concentration of $100{\mu}g/ml$. The extracts of the flower of Saxjfraga stolonifera, and stems of Euonymus japonica and Castanea crenata showed appreciable inhibitory activity (>50%) against HIV-1 protease at same concentration.

• Bulletin of the Korean Chemical Society
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• v.23 no.7
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• pp.1003-1010
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• 2002

Caspase 3, a member of cysteine protease family, is well known as a major apoptosis effector and is involved in cell death as a result of ischemic diseases such as stroke and myocardial infarction, therefore the inhibition of caspase 3 may protect those apoptotic cell damages. During the high-throughput screening of the compounds from the Korea Chemical Bank, berberine derivatives (A and B), an isoquinoline alkaloid, have been identified as potential inhibitors for caspase 3. Based on this finding we carried out molecular modeling study to identify the pharmacophoric elements of berberine structure which interact with a substrate-recognition binding site of caspase 3 and came up with several novel scaffolds. In this report, we will discuss the molecular modeling, syntheses and the enzyme inhibitory activities of these novel compounds.

• Archives of Pharmacal Research
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• v.28 no.2
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• pp.159-163
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• 2005

The effects of sedative peptide alkaloids from Zizyphus species on calmodulin- dependent protein kinase II were investigated. Protein kinase II activity was assayed on the basis of its ability to activate tryptophan 5-monooxygenase as its substrate in the presence of calmodulin. All thirteen alkaloids tested were stronger inhibitors than chlorpromazine ($IC_50,\;98{\mu}M$) on calmodulin-dependent protein kinase II. Among them, the most potent inhibitor was daechuine S27 ($IC_{50},\;2.95{\mu}M$), which was stronger than pimozide ($IC_{50},\;15.0{\mu}M$).

• Korean Journal of Clinical Pharmacy
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• v.8 no.2
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• pp.139-142
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• 1998

The effects of MeOH extracts from 28 herbal medicines on monoamine oxidase (MAO) activity were investigated. MAO was purified from mouse brain and its activity was determined by fluoro-photometry using kynuramine as a substrate. Three MeOH extracts, Coptis japonica, Cinnamomum cassia and Poncirus trifoliate from the herbal medicines showed a strong inhibitory effect with less than $100\;{\mu}g/ml$ in their inhibitory amounts of $50\%$ ($IC_{50}$ values) on MAO activity. Four MeOH extracts including Evodia officinalis exhibited a mild inhibition of MAO activity with $100-200\;{\mu}g/ml$ in their $IC_{50}$ values.

• KSBB Journal
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• v.6 no.4
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• pp.363-368
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• 1991

PVA degrading bacteria were isolated from water system, and identified as Pseudomonas cepacia and Pseudmonas pseudomallei, which were named as Pseudomonas sp. G5Y and Pseudomonas sp. PW. It was found out that those two kinds of bacteria have a symbiotic relationship to degrade PVA. For the mixed culture of these bacteria, the optimal conditions of pH, temperature, nitrogen source, and polymerization degree of PVA were found to be 7.5, $35^{\circ}C$, ammonium sulfate, and 500, respectively. Also, the growth of these bacteria was promoted by trace elements such as vitamin B1, B12, pyridoxine, and p-aminobenzoate, respectively. The specific growth rate of mixed bacteria was inhibited when the concentration of PVA was more than 20g/l. The substrate inhibition kinetics of the mixed culture was $${\mu}=\frac{0.065S}{2.56+S+(S^2/156}hr^{-1}$

• Korean Journal of Microbiology
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• v.25 no.1
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• pp.80-85
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• 1987

The aim of the present studies was to analyze the physiological background of ethanol inhibition in Zumomonas mobilis. The experiments were carried out with a number of continuous culture to give steady state concentration of ethanol. The domposition of fatty acids in the cells obtained from various conditions was analyzed and cell viability was also estimated. As results, it was found that vaccenic acid was the mafor fatty acid in the cell of Z. mobilis and the concentration was changed apparently to increase as increasing the concentration of ethanol produced from substrate utilization. Finally it was observed also that cell viability was decreased remarkably at the elevated ethanol concentration. Those changes might play important roles in the ethanol fermentation to give more complex phenomena observed at high concentration of ethanol.

• KSBB Journal
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• v.15 no.5
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• pp.474-481
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• 2000

The effects of growth substrates such as toluene and phenol on cometabolic biodegradation of trichloroethylene (TCE) by Burkholderia cepacia G4 were investigated. The dual effects of primary substrate on TCE biodegradation, stimulatory effects of toluene and phenol at low concentrations (0.5∼2 ppm & 0.1∼0.5 ppm, respectively) and a competitive inhibition at high concentration, were observed in batch experiments. These stimulatory effects of toluene and phenol were found to be due to the increments in the amount of reducing power like NADH which could be generated during the assimilation of toluene and phenol as the carbon and energy source. The efficiency of TCE biodegradation in trickling biofilm reactor (TBR) could be also enhanced up to the TCE removal efficiency of 58.1% by the supply of appropriate amounts of phenol (0.94∼4.7 ppm).

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.158.2-158.2
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• 2003

Vitamin K-related analogs induce growth inhibition in various cancer cell lines. We report that 2,3-dichloro-5,8-dihydroxy-1, 4-naphthoquinone (DDN), a naphthoquinone analog, induces mitochondria-dependent apoptosis in human promyeloid leukemic HL-60 cells. DDN induced cytochrome c release, cleavage of Bid, and activation of caspases -8, -9 and -3. Cleavage of Bid, the caspase-8 substrate, was inhibited by the broad caspase inhibitor zVAD-fmk, whereas cytochrome c release was not affected by zVAD-fmk. (omitted)