• Archives of Pharmacal Research
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• v.26 no.6
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• pp.458-462
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• 2003

The antioxidant activity of the stem bark from Albizzia julibrissin was evaluated for its potential to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, to inhibit the generation of the hydroxyl radical ($\cdot OH$), total reactive oxygen species (ROS) and to scavenge authentic peroxynitrites ($ONOO^{-}$). The methanol extract of A. julibrissin exhibited strong antioxidant activity in the tested model systems. Therefore, it was further fractionated using several solvents. The antioxidant activity of the individual fractions were in the order of ethyl acetate (EtOAc) ＞ n-butanol (n-BuOH) ＞ dichloromethane ($CH_2 CI-2$) ＞ and water ($H_2O$). The ethyl acetate soluble fraction, which exhibited strong antioxidant activity, was further purified by repeated silicagel, Sephadex LH-20 and RP-18 gel column chromatography. Sulfuretin (1) and 3 ,4 ,7-trihydroxyflavone (2) were isolated as the active principles. Compounds 1 and 2 exhibited good activity in all tested model systems. Compound 1 exhibited five times more inhibitory activity on the total ROS than Trolox. Compound 2 showed six times stronger DPPH radical scavenging activity than L-ascorbic acid. These results show the possible antioxidant activity of the A. julibrissin crude extract and its major constituents.

• Journal of Microbiology
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• v.37 no.1
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• pp.27-34
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• 1999

Two fractions with unusual antifungal activity that suppress asexual sporulation of several fungi were obtained from culture filtrate of Pseudomonas aeruginosa and were partially purified through the repeated silicagel flash column chromatographies. The sporulation-suppressive actions of these fractions in Aspergillus nidulans, Rhizopus stolonifer, and Coprinus cinereus, were analyzed by light and electron microscopes. The germination ability of the spores produced in the presence of these fractions were also checked to determine the persistent effects of these antifungal substances on the next generation. Light microscopic observation of developing sporangia of R. stolonifer grown in the presence of both fractions revealed that the significant number of sporangia failed to reach maturity, and frequently, uncontrolled growths of hyphae and rhizoids from the sporangiophores were found. In A. nidulans addition of these fractions appeared to cause different classes of morphological abnormality in conidia development, which included aborted formation of conidiogenous cells from the apex of conidiophores and enhanced hyphal growths either at the tip or middle of the conidiophores. Germination abilities of spores obtained from the cultures grown in the presence of antifungal fractions were 40∼60% in Aspergillus, 50∼80% in Coprinus (thallic spores), and 30∼40% in Rhizopus compared to those of normal spores.

• KSBB Journal
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• v.18 no.1
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• pp.70-73
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• 2003

TLC condition was developed for its simple separation and quantitative analysis of lactic acid. Rapid and clear separation of lactic acid by silica gel TLC plate was obtained by using nitromethane : 1-propanol : $H_2O$ (2 : 5 : 1.5, v/v/v) and a suitable dipping solution of 40 mg bromocresol purple in 100 mL 5% ethanol (pH 10.0). The lactic acid was shown as a bright yellow spot on a light cinnabar background. The quantitatively detectable concentration range of lactic acid was between 0.5 and 4% with 99.4%, confidence. Quantitative TLC analysis result was confirmed with HPLC and with enzymatic Quantitative analysis methods (by using lactate dehydrogenase).

• Korean Journal of Plant Resources
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• v.14 no.2
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• pp.116-123
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• 2001

The non-enzymatic antioxidants and antioxidant enzyme from the extracts of Parthenocissus tricuspidata PLANCH. were examined in order to utilize natural product for cerchemopreventive agents. The antioxidant potential and enzyme activities on plant positions in the extracts of Parthenocisuss tricuspidata PLANCH. showed considerable differences. The antioxidant activity of the leaf extracts by Ethyl acetate fractions of Parthenocisuss tricuspidata PLANCH. was the highest among three positions ($7.57\mu\textrm{g}/m\ell$). The highest activities showed in S-5 (in leaf), S-4 (in stem) and S-3 (in root) fraction by Silicagel column chromatography and the antioxidant activity showed, in purified extract of each positions, $7.06\mu\textrm{g}/m\ell$ (in leaf), $6.99\mu\textrm{g}/m\ell$ (in stem) and $12.39\mu\textrm{g}/m\ell$ (in root) respectively. The activities of DPPH by LH-20 column chromatography revealed much higher than those by silica-gel column chromatography. These were identified as the phenolic compounds known as antioxidant compounds such as Benzoic acid(Gallic acid), 1-methyl-3-(2-phenylethen) benzene, phloroglucinol and 1,2-dihydroxy-4-(1-propyl)benzene by GC/MS. POD activities in the stem and root were higher than in the leaf. SOD activity was highest in the leaf, stem and root activity was comparatively low. Especially, SOD activity in leaf was over 2 times higher than root.

• Microbiology and Biotechnology Letters
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• v.18 no.5
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• pp.496-500
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• 1990

When pepsin was used at a concentration of 8 mglml for hydrolysis of 0.02% casein, inhibitory activity of this inhibitor was proportional to a inhibitor concentration of 20 ${\mu}g$/ml, and fifty percent inhibition ($IC_{50}$) was observed to be 15 ${\mu}g$/ml. The inhibitor was pH-stable at pH range of 5-9 at $100^{\circ}C$ for 10 minutes and thermo-stable at pH 7.0 at $100^{\circ}C$ to give 100% activity for 20 minutes. The formation of pepsin-inhibitor complex was confirmed by sephadex 6-25 gel filtration and type of inhibition was determined as non-competitive inhibition by Lineweaver-Burk plot. The inhibitor strongly inhibited acid proteases such as pepsin and renin, and it was soluble in methanol very well. On TLC analysis of silicagel 60 using various sohent systems, the inhibitor gave a single spot at Rf range 0.4-0.6. From the result of IR spectrum and color reaction (Rydon-Smith, Biuret), this inhibitor was considered as peptide substance. Melting point and elemental contents were 220-$230^{\circ}C$, and C 50.61%-H 8.02%-N 9.34% (found), respectively.

• Korean Journal of Food Science and Technology
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• v.32 no.4
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• pp.949-958
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• 2000

Antimicrobial effects of 150 kinds of Korean and 82 kinds of Indonesian plants were investigated to develope natural food preservatives. Extracts of the plants with 70% ethanol were tested their antimicrobial effects against several food spoilage microorganisms, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans and Aspergillus niger. Seventeen kinds of Korean and eighteen kinds of Indonesian plants were found relatively effective, of which Myristica fragrans and Melaleuca leucadendra were the most effective, respectively. The major fractions of the two plant extracts showing antimicrobial activity were further purified by solvent fractionation, silicagel column chromatography and preparative HPLC. The purified substances were identified as limonene and caprylic acid in M. fragrans, and ${\alpha}-terpineol$ in M. leucadendra, respectively.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.6
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• pp.673-679
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• 2008

In this study, Mesoporous silica were prepared from hydrothermal synthesis using gel mixture of tetraethylorthosilcate (TEOS) as silica source and cetyltrimethylammonium bromide(CTMABr) as a template. In the optimum synthesis cause, molar ratio of template and silica changed. The surface and structure properties of Mesoporous silica were determined by XRD, SEM, and BET. N$_2$ adsorption isotherm characteristics, including the specific surface area(S$_{BET}$), total pore volume(V$_T$), and average pore diameter(D$_{BJH}$), were determined by BET. Also, the adsorption character of Pb(II) and Cd(II) ion on Mesoporous silica were measured using ICP. As a result, a SBET of 100$\sim$1,500 m$^2$/g was determined from the N$_2$ adsorption isotherm. Also, the average pore diameter of 2$\sim$4 nm. The adsorption of Pb ion and Cd ion on Mesoporous silica become different depending on the pH of solution. The adsorption amount of Mesoporus silica had higher than that of silicagel.

• Applied Biological Chemistry
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• v.23 no.3
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• pp.173-177
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• 1980

The anti-oxidant components in Panax ginseng, which were known to have antiaging effect, were fractionated by various solvents and then isolated by the preparative thin layer chromatography. A developing system with silicagel G using toluene-chloroform-actene (20 : 13 : 13) as mobile phase was applied. The components were investigated the anti-oxidant activity by ${\alpha}$, ${\alpha}'-diphenyl-{\beta}-picrylhydrazyl$ (DPPH) at 517nm. Two effective components were obtained from red ginseng and were indophenol reducing substances.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1221-1225
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• 2003

As an effort to select powerful anti-cariogenic materials from natural resources, various plant extracts were examined for their anti-S. mutans and anti-glucosyltransferase (GTase) activities. The ethanol extracts of licorice bark, which was produced after water extraction of licorice, showed the most powerful anti-S. mutans as well as anti-GTase activities. When licorice bark was consecutively fractionated with n-hexane, chloroform, ethylacetate, and butanol, the chloroform fraction exhibited the strongest anti-S. mutans activites. This fraction was further fractionated into 4 fractions through a silica gel column, and according to HPLC analysis, anti-S. mutant activities seemed to come mostly from relatively hydrophobic materials.

• Analytical Science and Technology
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• v.15 no.3
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• pp.300-316
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• 2002

The extraction methods of PBBs from environmental samples by soxhlet extraction for solid phase and liquid-liquid extraction for liquid phase were compared. After extraction, silicagel and florisil as column clean up methods were used for the comparison of cleanup efficiency with different solvent system. Also, the analytical instruments were used GC/MSD. The 22 kinds of PBBs standards were used to establish the analytical methods to perform the experiments of recoveries and detection limits in water and soil. The detection limits of PBBs represented 5~10 ng/L for water and 0.5~3.5 ng/g for soil samples, respectively. The recoveries of water samples represented 96~107% in n-hexane, dichloromethane and toluene for water, and 60~80% in combined solvent with n-hexane and acetone. The recoveries of soil sample were surveyed 67~97% in soxhlet extraction and 64~76% in ultrasonic extraction with selected solvents.