• Natural Product Sciences
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• v.10 no.5
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• pp.223-227
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• 2004

This study was carried out to investigate inhibitory effect of extracts from the root of Paeonia lactiflora on postprandial hyperglycemia. Organic solvent (hexane, ethyl acetate, butanol, aqueous) extracts from the crude drug were fractionated by high performance liquid chromatography. These fractions were examined to evaluate ${\alpha}-glucosidase$ (EC 3. 2. 1. 20) inhibition by microplate colorimetric assay. Among the fractions examined, the ethyl acetate fraction from the roots of Paeonia lactiflora showed potent inhibitory effects on ${\alpha}-glucosidase$. Therefore, further fractionation of the fraction was carried out to isolate the active principles. Finally, we isolated and Purified 1,2,3,4,6-penta-O-galloyl-beta-D-glucose (PGG) as a active principle by activity-guided fractionation. These results suggest that the extract from the root of Paeonia lactiflora can be used as a new nutraceutial for inhibition on postprandial hyperglycemia and PGG might be a candidate for developing an ${\alpha}-glucosidase$ inhibitor.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1979.04a
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• pp.116-116
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• 1979

In the experiment of cholesterols and steroidal compounds. gas chromatography has been widely used to determine the compounds. Without the facility, we could determine the amount of 17-ketosteroids in the use of t. 1. c technique. In the muicrobial conversion of cholesterol to 17-ketsoteroids, $\alpha,$ $\alpha'-dipyridyl$ which might be a inhibitor of $9\alpha-hydroxylase$ of steroid skeleton was added to microbial culture broth. The inhibitor contaminated due to its solubility in organic solvents and hindered the determination of 17-ketost eroids on t.1. c in all the process of the experiment. we successfully determined the 17-ketosteroids by the use of Ag$^{+}$ band on t. 1. c. plate.e.

• Journal of Electrochemical Science and Technology
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• v.6 no.1
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• pp.7-15
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• 2015

3-(4-Iodophenyl)-2-imino-2,3-dihydrobenzo[d]oxazol-5-yl 4-methylbenzenesulfonate (4-IPhOXTs) was synthesized and its inhibiting action on the corrosion of stainless steel 316L (SS) in sulfuric acid was investigated by means of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The results of the investigation show that this compound has excellent inhibiting properties for SS corrosion in sulfuric acid. Inhibition efficiency increases with increase in the concentration of the inhibitor. The adsorption of 4-IPhOXTs onto the SS surface followed the Langmuir adsorption model with the free energy of adsorption ΔG⁰_ads of −8.45 kJ mol⁻¹ . Quantum chemical calculations were employed to give further insight into the mechanism of inhibition action of 4-IPhOXTs.

• Journal of Electrochemical Science and Technology
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• v.10 no.1
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• pp.37-54
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• 2019

A new organic Schiff base compound N-benzylidene-2,5-dichloroaniline (BDC) was synthesized and the structure of the Schiff base is illuminated by some spectroscopic techniques. In addition, whether it is an applicable inhibitor in the industrial field was examined by conventional methods such as linear polarization resistance (LPR), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization for different concentrations. The BDC concentration and temperature effects were surveyed for elucidating the inhibitive mechanism. The BDC molecules are adsorbed to surface of mild steel via the Langmuir isotherm. Atomic force (AFM) and scanning electron microscope (SEM) techniques were utilized to give insight into surface characterization.

• Corrosion Science and Technology
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• v.22 no.1
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• pp.10-20
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• 2023

Because of its inexpensive cost, mild steel is frequently employed as a construction material in different industries. Unfortunately, because of its limited resistance to corrosion, a protective layer must be applied to keep it from decaying in acidic or basic environments. The presence of heteroatoms, such as nitrogen, oxygen, and pi-electrons in the Schiff base could cause effective adsorption on the mild steel surface, preventing corrosion. The weight loss method and scanning electron microscopy (SEM) were used to investigate the inhibitory effects of APIDO on mild steel in a 1 M hydrochloric acid environment. The efficiency of inhibition increased as the inhibitor concentration increased and decreased as the temperature increased. The SEM analysis confirmed that the corrosion inhibition of APIDO proceeded by the formation of an organic protective layer over the mild steel surface by the adsorption process. Simulations based on the density functional theory are used to associate inhibitory efficacy with basic molecular characteristics. The findings acquired were compatible with the experimental information provided in the research.

• Corrosion Science and Technology
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• v.7 no.4
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• pp.212-218
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• 2008

Inorganic ion exchange compounds (IECs) including hydrotalcites and bentonite clays are a well known classes of layered mixed metal hydroxides or silicates that demonstrate ion exchange properties. These compounds have a range of applications from water purification to catalyst supports. The use of synthetic versions of these compounds as environmentally friendly additives to paints for storage and release of inhibitors is a new and emerging application. In this paper, the general concept of storage and release of inhibiting ions from IEC-based particulate pigments added to organic coatings is presented. The unique aspects of the IEC structure and the ion exchange phenomenon that form the basis of the storage and release characteristic are illustrated in two examples comprising an anion exchanging hydrotalcite compound and a cation exchanging bentonite compound. Examples of the levels of corrosion protection imparted by use of these types of pigments in organic coatings applied to aluminum alloy substrates is shown. How corrosion inhibition translates to corrosion protection during accelerated exposure testing by organic coatings containing these compounds is also presented.

• Applied Biological Chemistry
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• v.33 no.3
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• pp.264-267
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• 1990

Representative synthetic piericidin-like compounds, such as hydroxypyridine and hydroxyquinoline derivatives, which showed high inhibition activity against NADH-ubiquinone oxidoreductase on the respiratory chain revealed good fungicide activity. Especially, hydrolrypyridine ones showed high activity against rice blast (Pyricularia oryzae) and barley powdery mildew (Erysiphe graminis).

• Environmental Analysis Health and Toxicology
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• v.19 no.4
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• pp.335-344
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• 2004

Diesel exhaust particle (<2.5 ${\mu}{\textrm}{m}$, DEP$_{2.5}$) is known to be probarbly carcinogenic (IARC group 2A). DEP$_{2.5}$ contains organic compounds such as polycyclicaromatic hydrocarbon (PAH), heterocyclic compounds, phenols, and nitroarenes. Reactive oxygen species (ROS) are generated by DEP$_{2.5}$ without any biological activation system. Therefore, an alternative mechanism by which DEP$_{2.5}$ could be carcinogenic is known by the generation of oxidative DNA damage. The aim of this study was to investigate genotoxic effects of DEP$_{2.5}$ using single cell gel electrophoresis. In order to evaluate the mechanisms of DEP$_{2.5}$ genotoxicity, the rat micro-some mediated and DNA repair enzyme treated comet assays together with routine comet assay were performed. DEP$_{2.5}$ was collected from diesel engine bus and dichloromethane extract was obtained. The organic extract of DEP$_{2.5}$ revealed DNA damage itself in NIH/3T3 cells. And it showed both oxidative and microsome mediated DNA damages. Vitamin C as an model antioxidant reduced DNA damage in endonuclase III treated comet assay. One of flavonoid, galangin as a CYP1A1 inhibitor reduced DNA damage in the presence of S-9 mixture. Our results show that DEP$_{2.5}$ are genotoxic and a great source of oxidative stress, but antioxidants can significantly reduce oxidative DNA damages. And DEP$_{2.5}$ may contain indirect mutagens which can be inhibited by CYP inhibitors.d by CYP inhibitors.

• Korean Journal of Organic Agriculture
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• v.19 no.spc
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• pp.271-274
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• 2011

Pepper mild mosaic virus (PMMoV) and cucumber mosaic virus (CMV) are important pathogens in various vegetable crops worldwide. We have found that methanol extracts of Quercus dentate (Oaimyo Oak) gal/nut strongly inhibit PMMoV and CMV infection. Based on this result, the inhibitor named as "KN0912" formulated from the extract of Q. dentate gallnut was tested for its inhibitory effects on PMMoV or CMV infection to each local lesion host plant (Nicotiana glutinosa; PMMoV, Chenopodium amaranticolor; CMV). Pre-treatment effect of KN0912 against infections of each virus to local host plant was measured to be $75.1{\pm}0.5{\sim}97.5{\pm}1.5%$ to PMMoV and $70.6{\pm}2.2{\sim}99.0{\pm}1.0%$ to CMV in 1~10mg/ml conc. and the absorption effect of the antiviral composition of KN0912 to the inside of tobacco leaves tissue, was inhibited by 55.7% to PMMoV and 63.8% to CMV. The persistence of KN0912 treatment was maintained until after the 3 days high inhibitory effect by 98% to PMMoV and by 95.1% to CMV. Inhibitory effects on systemic host plants of KN0912 were measured to be 80~90% to PMMoV and 60~75% to CMV. From the change of morphological characteristics of PMMoV particles under EM, we are tentatively suggested that one mode of action of KN0912 is inactivation due to the destruction of virus particles.

• Journal of Integrative Natural Science
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• v.15 no.3
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• pp.131-136
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• 2022

Cell migration is essential for diverse cellular processes including wound healing, immune response, development, and cancer metastasis. Pi3-kinase (PI3K) is a key regulator for actin cytoskeleton and phosphorylates phosphatidylinositol (4,5)-diphosphate (PIP2) to phosphatidylinositol (3,4,5)-trisphosphate (PIP3). High levels of PIP3 by PI3Ks are associated with increased levels of F-actin and pseudopod extension at the leading edge of migrating cells such as neutrophils and Dictyostelium. LY294002 is a well-known PI3K specific inhibitor. Here, we investigated the effect of LY294002 on cell migration. First, we evaluated the appropriate concentration of dimethyl sulfoxide (DMSO) for using as a solvent for LY294002. DMSO is a highly polar organic reagent and one of the most common solvent for organic and inorganic chemicals. Cell morphology and cell migration were unaffected at the concentrations less than 0.1 % DMSO. Therefore, stock solution of LY294002 was prepared so that the final concentration of DMSO was 0.1 % or less when treated. When cells were treated with LY294002, cell migration was increased in a concentration-dependent manner. The maximum speed was detected in the presence of 30 µM LY294002. These results suggest that PI3Ks play a inhibitory role in regulating cell migration in our experimental conditions.