• KSBB Journal
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• v.16 no.4
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• pp.344-350
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• 2001

The effect of salinity stress of Brassica olearacea and Capsicum annuum were studied at various levels of salinity conditions(Na-gluconate, K-gluconate, NaCl, KCl). The effects of salinity stress were measured by seedling growth rates and secondary metabolites contents of the stressed plants. Each seedling studied on the response of different salinity stress. Seedling growth of Capsicum annuum was inhibited up to 200 mM salt tolerance and Brassica olearacea was inhibited up to 400 mM salt tolerance. The produced anthocyanin was separated to high value from 200 mM NaCl in case of Brassica olearana and 50 mM K-gluconate in case of Capsicum annuum. The BADH activity was very high in Brassica olearacea seedlings treated with 200 mM NaCl and in Capsicum annuum seedlings treated with 100 mM K-gluconate. The BADH activities were increased during the early culture days, it induced betaine synthesis. The salinity stress promoted BADH activiy, subsequently endogenous betaine contents were increased, and it seemed to be secure seedling from salinity stress. The salinity concentration of 200 mM was effective on the inhibition of seed germination and on the increase of proline accumulation in tissue. The inhibition of seedling growth and accumulation of secondary metabolites in seedling were caused osmotic hypersensitivity against salinity stress.

• KSBB Journal
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• v.24 no.4
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• pp.397-402
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• 2009

The Portulaca oleracea (P. oleracea) is a popular herbal medicine in East Asia that was known to possess detoxification, antifebrile and antifungal effects. In the present study, we examined the biological activities of ethanol extracts of P. oleracea under various conditions with NIH3T3, B16F10, and MCF-7 cell line model systems. Extracts of P. oleracea (0.5 mg/ml) showed inhibition of expression of tyrosinase, but does not suppress either of TYRP-1 or DCT expression on B16F10 cells. Extracts of P. oleracea (2 mg/ml) showed anti-inflammatory effects on TNF-$\alpha$-stimulated NIH3T3/$NF{\kappa}B$-Luc cells and increase of the synthesis of collagen on NIH3T3 (wild type) cells. These results suggest that extracts of P. oleracea could be used as a functional biomaterial in developing a skin whitening agent and having the anti-inflammatory, anti-wrinkle, and anti-aging activities.

• Journal of Adhesion and Interface
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• v.11 no.2
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• pp.41-49
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• 2010

Furan-containing epoxide monomers (8, 9) were designed and synthesized as carbon-neutral, environment-friendly adhesion material. Bicyclic skeleton were constructed using the Diels-Alder reaction of furan and methyl acrylate, both readily accessible starting material from a biomass via bio-refinery process. After reduction of ester functionality, resulting hydroxyl moieties were coupled to epichlorohydrin to provide the epoxy-functionalized furanic monomers (8, 9). The structure of new furanic monomers was confirmed by $^1H$ and $^{13}C$ NMR spectroscopy. As UV-curable monomers, basic properties such as UV curing time and the extent of UV curing were evaluated by photo DSC. Photo-curing shrinkages were measured by linear variable differential transformer transducer (LVDT) and the effect of molecular structure on shrinkage was considered. In addition, new synthetic compounds showed the shear strength over 3 MPa when they were photo-cured between polycarbonate plates, which indicates these compounds are feasible to use as photo-curable adhesive materials.

• Polymer(Korea)
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• v.35 no.4
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• pp.350-355
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• 2011

A soluble polyamide containing photosensitive l,4-phenylenediacrylic acid (PDA) in main chain with biphenyl moiety was synthesized. The chemical structure of synthesized polyamide was investigated by means of $^1H$ NMR spectroscopy. The polymer was stable up to $280^{\circ}C$ and soluble in organic solvents, giving a good quality of thin films. The photoreaction of unpolarized LTV irradiated films was investigated by means of UV-vis absorption spectroscopy and FTlR spectroscopy, and liquid crystals (LCs) alignment property was examined by exposing to linearly polarized UV light (LPUVL) of 260~380 nm. The polyamide in film has excellent photoreactivity to unpolarized UV light. Direction selective photoreaction of PDA moiety in Lhe film was found to further induce nematic liquid -crystals to align along a perpendicular direction with respect to the electric vector of LPUVL, regardless of exposure energy of LPUVL. In addition, pretilt angle was measured by means of crystal rotation method. LPUVL-exposed polymer film induced the alignment of liquid-crystals (LC) with a pretilt angle of 0.2~$0.5^{\circ}$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.76-85
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• 2019

Recently, various investigation of vegetable oil which is extracted from natural resources is being progressed because of its low cost and environmental aspect. However, double bonds in vegetable oil should be substituted to other high reactive functional group due to its low reactivity for synthesizing bio-polymeric materials. ${\alpha}$-eleostearic acid, which is consist of conjugated triene, is the main component of tung oil, and the conjugated triene allows tung oil to have higher reactivity than other vegetable oil. In this study, tung oil is copolymerized with styrene and divinylbenzene to make thermoset resin without any substitution of functional group. Thermal and mechanical properties are measured to investigate the effects of the composition of each monomer on the synthesized thermoset resin. The result shows that the products have only one Tg, which means the synthesized thermoset resins are homogeneous in molecular level. Mechanical properties show that tung oil act as soft segment in the copolymer and make more elastic product. On the other hand, divinylbenzene acts as hard segment and makes more brittle product.

• Journal of the Korean Applied Science and Technology
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• v.36 no.1
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• pp.165-173
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• 2019

Hydrazine[$N_2H_4$] is a typical propellant for a rocket fuel in the field of aerospace. Since it is very toxic and harmful to the environment, various environmentally-friendly propellants have been developed. In this study, relatively a safe propellant, hydroxylammonium nitrate[$NH_3OHNO_3$], was prepared via a neutralization reaction of hydroxylamine[$NH_2OH$] and nitric acid[$HNO_3$]. FT-IR was used to analyze the chemical composition, chemical structure and functional groups of HAN. Thermogravimetric analysis showed the decomposition temperature of HAN. Ion chromatography was also used to evaluate the content of nitrate ions. It was proved that the peaks of FT-IR at $3161cm^{-1}$ and $1324cm^{-1}$ indicates the functionalities of N-H and N-O present in HAN. The decomposition temperature of HAN synthesized at pH 5 to 7 was $120-140^{\circ}C$, and pH 8 resulted in higher decomposition temperature than $140^{\circ}C$. Meanwhile, the sample obtained from pH 6-7 showed the concentration of nitric acid ion with 70%.

• Korean Journal of Food Science and Technology
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• v.51 no.3
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• pp.272-277
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• 2019

The effects of medium-chain enriched diacylglycerol (MCE-DAG) oil on hepatic cholesterol homeostasis were investigated. HepG2 hepatocytes were treated with either 0.5, 1.0, or $1.5{\mu}g/mL$ of MCE-DAG for 48 h. There was no evidence of cytotoxicity by MCE-DAG up to $1.5{\mu}g/mL$. The level of proteins for cholesterol uptake including CLATHRIN and LDL receptor increased by MCE-DAG in a dose-dependent manner (p<0.05). Furthermore, proprotein convertase subtilisin/kexin type 9, an inhibitor of LDLR, was dose-dependently diminished (p<0.05), indicating cholesterol clearance raised. MCE-DAG significantly increased 3-hydroxy-3-methylglutaryl-coenzyme A reductase and acetyl-CoA acetyltransferase2 (p<0.05), required for cholesterol synthesis, and their transcriptional regulator sterol regulatory element-binding protein2 (p<0.05). These findings suggest that given conditions of prolonged sterol fasting in the current study activated both hepatic cholesterol synthesis and clearance by MCE-DAG. However, total intracellular level of cholesterol was not altered by MCE-DAG. Taken together, MCE-DAG has the potential to prevent hypercholesterolemia by increasing hepatic cholesterol uptake without affecting intracellular cholesterol level.

• Journal of Applied Biological Chemistry
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• v.65 no.3
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• pp.231-237
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• 2022

Biorenovation is a method that converts existing compounds into new compounds through the enzymatic action of microorganisms. Biorenovation has expected effects such as reducing toxicity of compounds and increasing their activity. In this study, we successfully synthesized Luteolin-7-O-glucoside (L7G) through biorenovation and investigated its inhibitory effect on melanin production in α-Melanocyte stimulating hormone induced B16F10 mouse melanoma cells. We confirmed that Luteolin was toxic at 50, 100 and 200 µM, but our L7G in same concentration was not toxic for B16F10 mouse melanoma cells and also showed significant reduction in melanin production and tyrosinase activity. In addition, while investigating the effect of L7G on factors involved in melanin synthesis through western blotting, we were able to confirm that the MITF and tyrosinase protein synthesis was inhibited in treatment with L7G, however, tyrosinase related protein-1 (TRP-1) and dopachrome tautomerase (TRP-2) expression was not affected. So we derived a conclusion that through biorenovation we could produce compounds like L7G with improved activity and reduced toxicity for possible use as an active ingredient with whitening functionality in cosmetics.It also suggests that the application of biorenovation has potential usefulness in developing anti-inflammatory materials. It also suggests that the application of bio-renovation has potential usefulness in the development of inflammatory material. We applied Biorenovation technology to Distylium racemosum extract (DR) to generate Distylium racemosum biorenovation product (DRB), and investigated the anti-inflammatory properties of DRB in lipopolysaccharide (LPS)-treated RAW264.7 macrophages. We are applying technology to Biorenovation Distylium racemosum extract (DR) Distylium racemosum was to create a biorenovation product (DRB), lipopolysaccharide (LPS) investigated the anti-inflammatory properties of DRB in RAW264.7 macrophages treated for.

• Korean Journal of Microbiology
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• v.34 no.1_2
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• pp.26-30
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• 1998

Tetradecapeptide, Mastoparan B(MP B) and its [$Ala^2$]-, [$Ala^4$]-, [$Ala^6$]-, [$Ala^9$]-MP B derivatives were synthesized, and then their antibacterial and hemolytic activities were assayed to examine the effect of hydrophobicity and amphiphilicity on the MP B-induced those activities. MP B and more hydrophobic [$Ala^2$]-, [$Ala^4$]-MP B showed stronger antibacterial activity and less hydrophobic [$Ala^6$]-MP B than MP B did similar or weaker activity, so more hydrophobic [Ala]-MP B derivative had stronger activity. But more hydrophobic [$Ala^9$]-MP B than MP B showed weaker activity because of its Trp substitution by Ala. On the other hand, [$Ala^2$]- and [$Ala^4$]-MP B showed 100.0% and 69.4% hemolytic activity, but [$Ala^6$]-MP B did the weakest activity(6.1%) and [$Ala^9$]-MP B, weaker activity(26.0%) than MP-B. Therefore, more hydrophobic [Ala]-MP B derivative had stronger activity and the effect of amphiphilicity on the activity was weak.

• Development and Reproduction
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• v.11 no.2
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• pp.59-66
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• 2007

Understanding molecular mechanisms that control embryonic stem cell (ESC) self-renewal and differentiation is important for the development of ESC-based therapies. Statins, inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoA reductase), potently reduce cholesterol level. As well as inhibiting cholesterol synthesis, statins inhibit other intermediates in the mevalonate pathway such as farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP), major substrates for protein isoprenylation. Studies showed that pleiotropic effects of statins beyond cholesterol lowering property arise from inhibition of protein isoprenylation that is involved in various cellular functions including proliferation and differentiation. It has been determined that statins have inhibitory effect on ESC self-renewal and stimulatory effect on ESC differentiation into adipogenic/osteogenic lineages. Importantly, statins mediate downregulation of ESC self-renewal by inhibiting RhoA-dependent signaling, independently of their choresterol-lowering properties. Understanding statin's actions on ESCs may provide important insights into the molecular mechanisms that regulate self-renewal or differentiation of ESCs.