• Journal of the Korean Society of Safety
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• v.18 no.3
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• pp.94-100
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• 2003

Gel-like compounds containing flammable solvents were prepared to use fur cleaning agents in field of innovative industries and general purposes. And experiments were conducted to improve the defects of liquified flammable solvents from the view point of safety and health hazards. Flammable solvents used in this study were several single component flammable solvents(turpentine oil, N-methyl-2-pyrrolidone(NMP), d-limonene) and multi component flammable solvent(gasoline and ethanol). For gelation of flammable solvents, commercially Known as Aerosil(equation omitted) 200 fumed silica and triethanolamine(TEA) were used as gelation agent dispersant. The analyses on properties of gel-like compounds was studied by gelation and viscosity test pH test, volatility test and differential scanning calorimetry(DSC) measurement. The experimental results indicate that gel-like compounds containing flammable solvents have pH stability, high viscosity, volatile organic compounds(VOC) control by the decrease of volatility and odor component generation, fluidity control etc. From the experimental values, it can be predicted that the safety in the working place is improved by manufacturing flammable solvents into gel-like compounds.

• Polymer(Korea)
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• v.38 no.4
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• pp.425-433
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• 2014

In this study, microstructure and gel content (C-C) of polybutadiene rubber (PBR) were investigated using various techniques including ASTM D 3616, attenuated total reflectance Fourier transform infrared spectrometry (ATR FTIR), differential scanning calorimetry (DSC) and nuclear magnetic resonance spectroscopy (NMR). The ATR FTIR spectra of the samples were investigated to determine the cis, trans, 1, 2-vinyl and the C-C gel content in PBR. The absorbance ratios of specific peaks in different grades of PBR were correlated with the C-C gel content measured by the ATR FTIR techniques. Physico-mechanical and rheological properties of rubber compounds based on BR with various amounts of gel were determined. The results showed that there is an acceptable correlation between these properties and the C-C gel content of PBR.

• Fire Science and Engineering
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• v.22 no.5
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• pp.61-66
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• 2008

In this research, gel compounds containing thermochromic ingredients were manufactured and evaluated to prevent the transition hazards of fire and explosion, which they are one of the methods for detecting abnormal conditions caused by overheating of special materials early. And also, compounds of viscoelastic and brushing types were manufactured as the kind and content of raw materials, and manufacturing process to enlarge the application for overheat-detecting targets. Test methods were conducted as chromism test, viscosity profile, starting time of thermochromism, and FT-IR analysis. Thermochromic gel materials exhibit chromism properties that can detect abnormal conditions effectively, and then they are possible to various applications.

• Analytical Science and Technology
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• v.7 no.3
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• pp.403-411
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• 1994

To isolate, purity and identify of bioactive compounds involved in alfalfa allelopathy and/or autotoxicity, experiment was conducted. Isolation and separation procedures used from an 80% methanol extract of fresh alfalfa leaves(1kg), silica gel thin layer chromatography(TLC), followed by Droplet Counter Current Chromatography(DCCC). Preliminary identification was examined by high preformance lipid chromatography(HPLC). Four phenolic compound, salicylic acid, scopoletin, rutin, and quercetin, were identified and identified all compounds were phytotoxic to alfalfa seed germination and seedling growth. Among these compounds, quercetin treatment($10^{-3}M$) was most inhibitory to alfalfa seed germination and seedling growth. These compounds may be, at least in part, involved autotoxicity and allelopathy.

• Microbiology and Biotechnology Letters
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• v.23 no.2
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• pp.170-177
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• 1995

To search and develop the compounds exhibiting antifungal activities against the mycelial phase of Candida albicans, approximately 2,900 microorganisms isolated from soil were examined for antifungal activity. Among them, a strain with preferential activity against the mycelial phase of Candida albicans was isolated and identified as Streptomyces sp. A393. Isolation and purification of compounds A393 showing antifungal activity against the mycelial phase of C. albicans were performed using XAD-7 column chromatography, silica gel chromatography, preparative thin- layer silica gel chromatography, and HPLC. The molecular weights of compounds isolated from Streptomyces sp. A393 were determined as 774, 790, 804 and 820. These compounds appeared to have a structure of macrolide antibiotics, oligomycin A, B, C and E. Especially, oligomycin E, which is formerly reported to have no antifungal activity, showed antifungal activity against the mycelial phase of Candida albicans.

• Korean Journal of Pharmacognosy
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• v.45 no.2
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• pp.93-100
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• 2014

The Acer tegmentosum (3 kg) were extracted with boiled water and the freeze dried extract powder was partitioned with $CH_2Cl_2$, EtOAc, n-BuOH and $H_2O$, successively. From the EtOAc and n-BuOH fraction, six phenolic compounds were isolated through the silica gel, octadecyl silica gel and sephadex LH-20 column chromatography. On the basis of spectroscopic methods, such as $^1H$-NMR and $^{13}C$-NMR, and LC/MS, the chemical structures of the compounds as feniculin (1), avicularin (2), (+)-catechin (3), (-)-epicatechin (4), salidroside (5) and 6'-O-galloylsalidroside (6). In this study, compounds 1 and 2 have been first isolated from the A. tegmentosum. To provide insight into the effects of six compounds isolated from A. tegmentosum on inflammation, we investigated its effect on nitric oxide (NO) production in RAW 264.7 cells using lipopolysaccharide (LPS) stimulation. Compounds 1 and 6 slightly repressed NO production. Also, compounds 3 and 4 inhibited NO secretion with statistical significance. However, compounds 2 and 5 did not show any inhibitory effect on NO production.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.4
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• pp.239-243
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• 2007

When Perfluorinated Compounds (PFCs) are applied in cosmetic products, they have many merits because of unique feeling and characters. However, it is very difficult to use them as cosmetic ingredients because they are insoluble material in oil and water and have high specific gravity. To develop a special system to stabilize PFCs in cosmetic products, we compared three systems, of gel network system, spherulite lamellar system, and nanostructure system. We found that nanostructure system was the optical system for stabilizing PFCs.

• Korean Journal of Food Science and Technology
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• v.35 no.5
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• pp.959-967
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• 2003

The polyphenol compounds of Korean pears were extracted with 60% acetone for 4 days at room temperature and purified using Sephadex LH-20 column chromatography, MCI gel column chromatography, Bondapak $C_{18}$ column chromatography, TLC, and HPLC. As a result, three compounds were isolated. The chemical structures of each compound were determined and identified using NMR, FAM-mass, and FT-IR. The compounds were confirmed as (+)-catechin (compound A), (+)-gallocatechin (compound B), (-)-epigallocatechin (compound C), and procyanidin B-3-3-o-gallate (compound D).

• Journal of Life Science
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• v.21 no.9
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• pp.1323-1328
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• 2011

We herein report the development of an agarose-gel-immobilized recombinant bacterial biosensor simple system for the field monitoring of phenolic compounds. Escherichia coli cells harboring the pLZCapR plasmid, which was previously designed to express the ${\beta}$-galactosidase reporter gene in the presence of phenolic compounds, were co-immobilized with a substrate [chlorophenol red ${\beta}$-galactopyranoside (CPRG) in agarose gel, and dispensed to the wells of a 96-well plate. Field samples were added to the wells and color development was monitored. In the presence of 5 ${\mu}M$ to 10 mM of phenol, the biosensor developed a red (representing hydrolysis of CPRG) color. Other phenolic compounds were also detected by this immobilized system, with the pattern resembling that previously reported for the corresponding non-immobilized biosensor. The immobilized cells showed optimum activity when the gel was simultaneously supplemented with 6% dimethyl formamide (DMF), 0.1% SDS and 10 mM $CaCl_2$. The immobilized biosensor described herein does not require the addition of a substrate or the use of unwieldy instruments or sample pretreatments that could complicate field studies.

• Applied Biological Chemistry
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• v.45 no.4
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• pp.212-217
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• 2002

We purified polyphenols from persimmon leaf and tested their biological activity. The 60% acetone extract was lyophilized and applied to test enzyme inhibition of glucosyltransferase and tyrosinase. GTase was 82.4% inhibited at $1.8{\times}10^{-1}$ mg/ml and tyrosinase 21.7% inhibited at 0.8 mg/ml. The acetone extract was fractionated into F-1, 2, 3, 4, 5 by Sephadex Q-50 gel filtration and the fraction-1 and 2 showed higher enzyme inhibition activity than the other fractions. To the Proteinase K treatment and autoclaving of the two fractions had no effect on the enzyme activity, but these results suggested that active fraction was not protein but phenol ring completed compounds. By Sephadex LH-20, MCI-gel and Bondapak $C_{18}$ column chromatographies, compouds 1, 2, 3 and 4 from F-1 fraction, compounds 5 and 6 from F-2 fraction and compounds 7 , 8 from F-3 fraction were purified and re-crystallized. The purified compounds was assumed to be condensed tannins of frame flavan-3-ol frame on the basis of color reagent reaction and to be a mixture of monomer, dimer and trimer according to TLC analysis.