• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.34-37
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• 1998

Combinatorial chemistry is one of the most interested topics in the area of drug discovery. One of the most important points is how to find a lead compound that gives the seed structure for designing of a combinatorial library. Natural products is suitable for searching a new bioactive compound with new structure. We have carried out systematic screening works to find natural products possessing the effects on inter-and intra-cellular signaling. Two hundreds extracts of medical plants and two thousands microbial culture broth samples have been tested for the induction and inhibition of IL-2 or IL-6 production (Fig. 1). ELISA is an efficient method for screenings from such a large number of samples. Now, we apply this method to search prion- binding agents.

• Archives of Pharmacal Research
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• v.22 no.2
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• pp.225-227
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• 1999

A new acylcic deterpene (1) and a known acyclic diterpene 12(S)-hydroxygeranyleraniol (2) were isolated form the aerial parts of Carpesium divaricatum. The structure of 1 was determined to be (2E, 10E)-1, 12-dihydroxy-18-acetoxy-3,7,15-trimethylhexadeca-2,10,14-triene (1) on the basis of spectroscopic studies. Compounds 1 and 2 exhibited cytotoxicity against cultured human tumor cell lines, A549, SK-OV-3, SK-MEL-2, XF498, and $HCT_{15}$, with $ED_{50}$ values ranging from 4.3-10.2 ${\mu}g/ml$ and 4.1-8.3 ${\mu}g/ml$, respectively.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.146.1-146
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• 2003

Transgenic Nicotiana benthmiana plants harboring and expressing coat protein (CP) gene of Zucchini green mottle mosaic virus (ZGMMV) were generated for both virus-resistant screening and complementation analysis of related viruses and environmental safety assessment (SA) of living modified organism (LMO) purposes. Transformation of leaf disc of N. benthamiana was performed using Agrobacterium-mediated method and the pZGCPPGA748 containing the ZGMMV CP and NPTII genes. Two kinds of transgenic homozygous groups, virus-resistant and -susceptible lines, were obtained by screening of challenging homologous virus for T1 generations. Complementation of CP-deficient related virus was analyzed using the susceptible line of ZGMMV. These two pathologically different lines can be useful for host-virus interactions and LMO environmental SA.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.04a
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• pp.90-90
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• 1997

Natural products, which have been used for the treatment of hypertension, diuresis and nephritis in traditional oriental medicine, were selected for the screening of nitric oxide (NO) production in endothelial cells and kidney tissues in vitro as well as in vivo by measuring the conversion of [$\^$14/C]-L-arginine to [$\^$14/C]-L-citrulline, a coproduct of the enzyme reaction with NO. Confluent monolayer of endothelial cells were used for the screening of 16 natural products. Among the natural products, Zizyphus jujuba and Codonopsis pilosula stimulated endothelial NO synthase activity. Thus, both confluent monolayer of endothelial cells and kidney homogenates (glomeruli, cortical tubules, meudllae) were treated with Zizyphus jujuba and Codonopsis pilosula (final concentration 10 $\mu\textrm{g}$/$m\ell$) and NO releases were compared with those by receptor - dependent agonists, bradykinin and ADP and receptor - independent calcium ionophore A23187 in vitro. In rat experiment, NO releases in glomeruli, cortical tubules and medullae and plasma renin activity were assessed after intraperitoneal injection of Zizyphus jujuba and Codonopsis pilosula (10 mg/kg/day for 4 days). As a result, both Zizyphus jujuba and Codonopsis pilosula significantly increased NO releases in cultured endothelial cells, kidney tissues in vitro as well as in vivo. Stimulation of NO releases by Zizyphus jujuba and Codonopsis pilosula was similar to those by receptor - dependent agonists, bradykinin and ADP and receptor - independent calcium ionophore A23187 in cultured endothelial cells. However, plasma renin activity was not influenced by these two natural products. In conclusion, stimulatory effects of Zizyphus jujuba and Codonopsis pilosula on NO release in kidney may contribute their hypotensive effects and antinephritic action possibly by increasing renal blood flow.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.306-306
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• 2017

Screening for drought and salinity tolerance was undertaken for selected Philippine upland rice landraces during germinative and seedling stages to identify varieties which can potentially be grown in marginally dry and saline soils. While increasing PEG and NaCl concentrations caused obvious signs of injury to all rice genotypes, considerable varietal differences were noted in the nature of responses providing evidence that these genotypes possess broad intraspecific genetic variations for drought and salt tolerance. Inconsistent responses of these varieties during both growth stages highlight complexities involved in stress responses and underscore the futility of utilizing a single stage in the rice plant's life cycle for physiological screening. Notwithstanding these perplexing responses, G_Katiil and Ml-Pilit Tapul were observed to thrive relatively well despite increased salt and drought stress during early growth stages and may therefore possess genes needed in crop improvement efforts for drought and salinity tolerance. While these results do not reflect the entire spectrum of adaptive expression to drought and salinity stress during the life cycle of the upland rice plant, they nonetheless provide an easy, reliable and reproducible method for preliminary identification of drought and salt tolerant rice varieties.

• Proceedings of the Zoological Society Korea Conference
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• 2001.10a
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• pp.265.1-265
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• 2001

No Abstract, See Full Text

• Proceedings of the Zoological Society Korea Conference
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• 2001.10a
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• pp.261.3-262
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• 2001

No Abstract, See Full Text

• Biomolecules & Therapeutics
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• v.4 no.3
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• pp.291-295
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• 1996

For the screening of antidiabetic effect, this study was carried out to some natural products by measurements of glucose level. MeOH and $CH_2Cl_2$ extracts of natural products were investigated for the effect on glucose level of $N_2$-STZ diabeted Rat. Among the natural products, Dioscorea Rhizoma, Trichosanthes Radix, Nelumbis Semem and Lycii Fructus were shown a remarkable antidiabetic effect.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1505-1508
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• 2012

Protein tyrosine phosphatase 1B (PTP1B) is a key factor in negative regulation of the insulin pathway, and is a promising target for the treatment of type-II diabetes, obesity and cancer. Herein, compound ($\mathbf{4}$) was first observed to have moderate inhibitory activity against PTP1B with an $IC_{50}$ value of $13.72{\pm}1.53{\mu}M$. To obtain more potent PTP1B inhibitors, we synthesized a series of chalcone derivatives using compound ($\mathbf{4}$) as the lead compound. Compound $\mathbf{4l}$ ($IC_{50}=3.12{\pm}0.18{\mu}M$) was 4.4-fold more potent than the lead compound $\mathbf{4}$ ($IC_{50}=13.72{\pm}1.53{\mu}M$), and more potent than the positive control, ursolic acid ($IC_{50}=3.40{\pm}0.21{\mu}M$). These results may help to provide suitable drug-like lead compounds for the design of inhibitors of PTP1B as well as other PTPs.

• Proceedings of the PSK Conference
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• 2000.10a
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• pp.155.1-155.1
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• 2000