• YAKHAK HOEJI
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• v.46 no.2
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• pp.124-128
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• 2002

The nitrone-based free radical trapping reagent, $\alpha$-phenyl-n-tert-butyl nitrone (PBN) has been proposed as therapeutic agent for stroke. We used this for model drug of development of new drug for neuroprotection. The purpose of this study was to evaluate the blood-brain barrier (BBB) permeability of PBN in Sprague-Dawly (SD) rats. The BBB transport of PBN was investigated in SD rats using internal carotid artery perfusion (ICAP) method at a rate of 4 mι/min for 15 second. We also obtained pharmacokinetic parameters of PBN using single intravenous injection technique. When we estimated BBB permeability of PBN with ICAP method, the brain volume of distribution of PBN was 60.0 $\pm$ 12.0 $\mu\textrm{g}$/ι. The brain uptake of PBN after IV injection at 120 min was 0.15 $\pm$ 0.01%ID/g. The PBN was transported to the brain through the BBB well in rats, because PBN is small molecule (MW 177) and lipid-soluble (log P 1.23) compound.

• Archives of Pharmacal Research
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• v.20 no.2
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• pp.184-190
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• 1997

A new method based on the chemical reaction has been devised for the sequential analysis of reducing oligosaccharides using 8-amino-2-naphthalenesulfonic acid (ANS), a fluorescent precolumn derivatization reagent for reducing saccharides. The procedure established includes 1) the derivatization of a reducing oligosaccharide to produce a Schiff base, 2) the reduction of the base with sodium cyanoborohydride $(NaBH_3/CN), 3)$ the methoxycarbonylation of the resultant secondary amino group, 4) the cleavage of the glycoside bond next to the reducing end, based on the intramolecular acid hydrolysis by the action of a sulfonic acid group of the ANS derivative, 5) the identification of the liberated reducing end by high-performance liquid chromatography (HPLC), and finally 6) the recovery of the resultant oligosaccharide fragment from the cleavage reaction mixture. The extensive examination of the conditions for the sequential analysis of reducing oligosaccharides resulted in the procedure of simplicity , high selectivity and high recovery. This procedure was found to be useful for the sequential analysis of di-, tri- and tetrasaccharides.

• Journal of Microbiology and Biotechnology
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• v.26 no.12
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• pp.2051-2059
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• 2016

To date, there has been no employment of a magnetoelastic (ME) biosensor method to detect Salmonella enterica serovar Typhimurium in soil. The ME biosensor method needs to be investigated and modified for its successful performance. The filtration method, cation-exchange resin method, and combinations of both methods were employed for the extraction of S. Typhimurium from soil. The number of S. Typhimurium and the resonant frequency shift of the ME sensor were then compared using a brilliant green sulfa agar plate and an HP 8751A network analyzer. A blocking study was performed using bovine serum albumin (BSA), polyethylene glycol (PEG), and casein powder suspension. Finally, the modified ME biosensor method was performed to detect S. Typhimurium in soil. The number of S. Typhimurium was significantly decreased from 7.10 log CFU/soil to 4.45-4.72 log CFU/soil after introduction of the cation-exchange resin method. The greatest resonant frequency shift of the measurement sensor was found when employing centrifugation and filtration procedures. The resonant frequency shift of the PEG-blocked measurement sensor was $3,219{\pm}755Hz$, which was significantly greater than those of the BSA- and casein-blocked ME sensor. The optimum concentration of PEG was determined to be 1.0 mg/ml after considering the resonant shift and economic issue. Finally, the modified ME biosensor method was able to detect S. Typhimurium in soil in a dose-response manner. Although these modifications of the ME biosensor method sacrificed some advantages, such as cost, time effectiveness, and operator friendliness, this study demonstrated a novel approach of the ME biosensor method to detect S. Typhimurium in soil.

• Journal of the Korean Chemical Society
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• v.7 no.4
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• pp.299-303
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• 1963

A method of the colorimetric determination of titanium has been developed, based on the fact (IV) forms a stable blue complex with methylthymolblue(MTB) which is suitable for spectrophotometric determination of titanium in the concentration range of 0.2 to 22 $\mu$g per ml as $TiO_2$. The determination was carried out in the solution of pH range of 2.6 to 3.6, and the absorbancy of complex was at 600m$\mu$ with Coleman spectrophotometer. Titanium forms a 1:1 complex with MTB, which has a molar absorptivity, $1.1{\times}10^4$ at 600m\mu$. The effects of hydrogen ion concentration, reagent concentration, stability of complex, and hydrolysis were studied. Most of cations do not interfere seriously; however, many of anions such as oxalate, citrate, phosphate, chloride interfere in this determination.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.188-191
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• 2002

A glucan and a fructan producing enzymes from Leuconostoc mesenteroides NRRL B-1149 were prepared and concentrated from the cu1ture of 1.5% sucrose using polysulfone ultrafiltration hollow fiber in the presence of 0.1% (w/v) Tween 80, 1 mM $CaCl_2$, and 0.02% $NaN_3$. The molecular masses of the enzymes were estimated to be about 213.6 kDa and 180 kDa, respectively, based on the PAS staining for the glucosyltransferase and Mukasa method for fructosyltransferase. Polymers produced by the enzymes showed different solubility; an insoluble glucan and a soluble fructan. The linkages of polymers were determined by methylation using Hakomori reagent and following acid hydrolysis. The glucan was composed of ${\alpha}$-1,6 and 1,3 linkages and the fructan showed similar linkage data of levan.

• Analytical Science and Technology
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• v.35 no.5
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• pp.189-196
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• 2022

When cationic basic compounds are chromatographed using hydro-organic mobile phase, the presence of anionic free silanols in the silica-based stationary phases results in broad and asymmetrical peaks. The addition of an ionic reagent to the mobile phase prevents analytes from accessing free silanols, improving peak shape. In this study, the chromatographic behavior of salbutamol sulfate as a basic compound was investigated under various conditions, including the use of different columns, mobile phases, and ion-pair reagents such as triethanolamine (TEA) and sodium heptane sulfonate (SHS). The retention and peak shape of chromatograms were both evaluated. The results show that pre-conditioning the column with TEA and including it in the mobile phase can prevent cationic analytes from accessing anionic silanols, resulting in improved peak shape. Furthermore, buffering the mobile phase is an important factor in keeping the pH constant throughout the process. The chosen method was validated in part. This study could be helpful for researchers and analyst to solve such problems with cationic basic components.

• Bulletin of the Korean Chemical Society
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• v.33 no.1
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• pp.171-176
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• 2012

A novel chemiluminescence (CL) system was established for the determination of cytosine arabinoside (Ara-C) in pharmaceutical preparations. It was showed that a clear CL signal was observed when Eosin Y mixed with Fenton reagent. The CL intensity was decreased significantly when Ara-C was added to the reaction system and partially scavenged the hydroxyl radicals in the solution. The extent of decrease in the CL intensity had a good stoichiometrical relationship with the Ara-C concentration. Based on this, we developed a new method for the determination of Ara-C using a flow injection analysis (FIA) technique with CL detection. Under the optimal conditions, the linear range of Ara-C concentration was $6.0{\times}10^{-9}\sim1.0{\times}10^{-7}mol/L$ (R = 0.9982) with a detection limit of $7.6{\times}10^{-10}mol/L$ (S/N=3), the RSD was 5.6% for $6.0{\times}10^{-8}mol/L$ Ara-C (n = 11). The method was successfully applied to the determination of Ara-C in injection samples. The possible chemiluminescence reaction mechanism was discussed.

• Journal of Korean Society for Atmospheric Environment
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• v.31 no.3
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• pp.302-314
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• 2015

There is an adsorption method using activated carbon as a typical method for removing elemental mercury. Physical characteristics of activated carbon such as specific surface area and volume of pore (micro and meso) have positive effect for mercury adsorption. Activated carbon is carbon-based material with a high specific surface area. This activated carbon can be manufactured through carbonization and activation process. In this process, physical characteristics of specific surface area and pore distribution are changed by controlling operating parameters like temperature, time and reagent of activation. In this study, we evaluated characteristics of activated carbons manufactured from pinewood and coal with the operating parameters. We evaluated mercury adsorption capacities of the activated carbons having excellent physical characteristics and compared those to the commercial activated carbon.

• Journal of Biosystems Engineering
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• v.30 no.4 s.111
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• pp.242-248
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• 2005

There was no useful milling standard to produce high quality milled rice efficiently and adequately in Rice Processing Complex. Therefore, the whiteness of milled rice produced Rice Processing Complexes were different according to Rice Processing Complexes and milling periods at the same Rice Processing Complex. This research was carried out to contribute the production and distribution of high quality milled rice through determination of whiteness condition of milled rice as a milling stndard based on degree of bran removal using New $May-Gr\ddot{u}wald$ reagent dyeing method and taste of cooked rice. The optimum whiteness value of milled rice for efficient milling in Rice Processing Complex was found to be from 40 to 41, while the degree of milling was from $8.9\%\;to\;9.2\%.$ At this whiteness condition, the first derivative of whiteness value according to degree of milling was higher than the average value from brown rice to well milled rice, and the broken kernel ratio was from $3.0\%\;to\;3.4\%.$ This whiteness condition ($40\~41$) could be considered as a milling condition in Rice Processing Complex.

• Analytical Science and Technology
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• v.16 no.6
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• pp.458-465
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• 2003

The HS (headspace)-SPME (Solid phase microextraction) as rapid and simple method was performed for the determination of volatile fatty acids (VFAs) from the aqueous samples. In-fiber derivatization of VFAs with 1-Pyrenyldiazomethane (PDAM) was applied to improve their sensitivity of detection. In SPME procedure, typical parameters such as effects of solution pH, and salting out reagent and ultrasonication were investigated to improve the extraction efficiency. Based on the developed method, VFAs in wastewater samples were determined by gas chromatography / mass spectrometry-selected ion monitoring (GC/MS-SIM) mode.