• Journal of Microbiology and Biotechnology
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• v.18 no.7
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• pp.1298-1307
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• 2008

In this study, we investigated the inhibition effects of single and mixed heavy metal ions ($Zn^{2+},\;Ni^{2+},\;Cu^{2+},\;and\;Cd^{2+}$) on iron oxidation by Acidithiobacillus ferrooxidans. Effects of metals on the iron oxidation activity of A. ferrooxidans are categorized into four types of patterns according to its oxidation behavior. The results indicated that the inhibition effects of the metals on the iron oxidation activity were noncompetitive inhibitions. We proposed a reduced inhibition model, along with the reduced inhibition constant ($\alpha_i$), which was derived from the inhibition constant ($K_I$) of individual metals and represented the tolerance of a given inhibitor relative to that of a reference inhibitor. This model was used to evaluate the toxicity effect (inhibition effect) of metals on the iron oxidation activity of A. ferrooxidans. The model revealed that the iron oxidation behavior of the metals, regardless of metal systems (single, binary, ternary, or quaternary), is closely matched to that of any reference inhibitor at the same reduced inhibition concentration, $[I]_{reduced}$, which defines the ratio of the inhibitor concentration to the reduced inhibition constant. The model demonstrated that single metal systems and mixed metal systems with the same reduced inhibitor concentrations have similar toxic effects on microbial activity.

• The Korea Journal of Herbology
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• v.20 no.3
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• pp.83-92
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• 2005

Objectives : The physiological activities of Coptidis Rhizoma investigated for application as a cosmetic ingredients. Methods : We were experimented anti-oxidation effect, growth inhibition ability on cancer cells, antibacterial activity on various kinds of bacteria of skin. Results : The results were obtained as follows : Electron-donating ability(EDA) shows that Coptidis Rhizoma extracted with ethanol(94.51%) gives higher EDA in comparison to that extracted with water in 1000 ppm(63.24%). In the test of SOD-like activity, ethanol extract showed quite more activity with 81.01% in 1000 ppm, while water extract was low in 18.22%. In the inhibition activity of Xathine oxidase, ethanol extract showed higher inhibition activity compared to water extract. In measuring lipid oxidation inhibition ability using fish oil, ethanol extract in 100 ppm showed prominent ability. In the oxidation inhibition effect added with $Cu^{2+}\;ion\;and\;Fe^{2+}$ ion as a oxidation promoter, ethanol extract in 1000 ppm, each in the proportion of 90% and 92%, showed high oxidation inhibition effect compared with water extract. Conclusions : The results indicated that, ethanol extract which is superior in its anti-oxidation and antibacterial effect is useful to be applied in cosmetic industry.

• The Korea Journal of Herbology
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• v.26 no.1
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• pp.111-117
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• 2011

Objectives : The present study was designed to investigate effects of mixed extract from korean medicinal herbs (MIX) on oxidation/reduction reaction-related and aging-related enzyme in vitro. Methods : We performed MTT assay, collagenase inhibition assay, elastase inhibition assay, tyrosinase inhibition assay, DPPH free radical scavenging assay, SOD-like activity and xanthine oxidase inhibition assay. Results : Recently, many studies have reported that elastin is also involved in inhibiting or repairing wrinkle formation, although collagen is a major factor in the skin wrinkle formation. The MIX showed 97% inhibition of collagenase activity, and 64% inhibition of elastase activity at 1 mg/ml concentration of MIX, next only to positive control, which indicate good efficacy for anti-wrinkle ingredient. Also it's treatment showed 34% inhibition of tyrosinase activity, to relate whitening effect, at the same dose of MIX. Antioxidant activities were determined by DPPH radical scavenging, xanthine oxidase (XO) inhibiting activity and SOD-like activity. Also these scavenging, XO-inhibiting and SOD-like activities were measured in 91%, 80%, and 63% inhibition, respectively, at a treated dose of 1 mg/ml, compare to control. Conclusions : These results suggest that possibility of mixed korean medicinal herbs as a functional ingredient for anti-wrinkle and whitening, anti-oxidation and anti-aging cosmetic formula.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.1
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• pp.64-73
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• 2007

The catalytic activity of transition metals (Cu, Co, Mn, Fe and Ni) supported on ${\gamma}-Al_2O_3$ for the oxidation of toluene was investigated in the microreactor of fixed-bed type. The catalytic activity of transition metals for the oxidation of toluene turned out to be increasing in the order of Ni$Cu/{\gamma}-Al_2O_3$ catalysts for the oxidation of toluene increased with the increasing loadings of copper, reached the maximum activity at 5% loadings of copper, and decreased with higher loadings of copper in the catalysts. The activity of $Cu/{\gamma}-Al_2O_3$ catalysts for the oxidation of toluene decreased with the increasing calcination temperatures. This might result from the decreasing surface area of catalysts due to the sintering of copper oxide as well as ${\gamma}-Al_2O_3$ supports. The 5wt% $Cu/{\gamma}-Al_2O_3$ catalysts calcined at $400^{\circ}C$ for 4 hrs in the air showed the highest activity for the oxidation of toluene. Mutual inhibition was observed for the binary mixture of toluene and xylene. The activity of the easy-to-oxidize toluene was greatly decreased while the difficult-to-oxidize xylene was slightly decreased in the binary mixture of toluene and xylene. It might suggest that the inhibition of toluene and xylene in the binary mixture resulted from the competitive adsorption for the adsorbed oxygen on the catalytic surface.

• The Korea Journal of Herbology
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• v.22 no.2
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• pp.51-63
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• 2007

Objectives : For the congenital feeble, the Gongjindan is useful medicine. The experiment is to estimate the value of the Gongjindan as therapeutic agent preventing against aging with an analysis of the ingredients and the bio-activating effects by enzymologic methods. Methods : General ingredients' of the Gongjindan's extract were analyzed first and the quantitative analysis of a reducing sugar, a soluble protein, an amino acid and minerals was made. The Gongjindan, which is extracted, concentrated, and freeze drying with water, ethanol and chloroform, have got applied for the experiment. The effects on electronic donating ability, SOD-like activity, nitric oxide inhibition, xanthine oxidase inhibition, whitening effect have been investigated in the physiological activity measurement of function experiment. Results : The contained amino acid, in order of high amount, is Arginine, Alanine, Glutamic acid, Proline and the contained free amino acid is Glutamic acid, Leucine, Lysine, Phenylalanine. The derivative of free amino acid is ${\gamma}-Aminoisobutyric$ acid, Phosphoserine, Taurine. And the Gongjindan is containing 13 species of minerals in order of Ca>K>Na>Mg>Fe>AI>Mn. Then, to assure of the Gongjindan's capability of anti-oxidation, these following subjects-polyphenol, electronic donating ability, SOD-like activity, nitric oxide inhibition, xanthine oxidase inhibition, tyrosinase inhibition- are analyzed and show high activity especially the most in ethanol extracts. Conclusion : With this analysis of ingredients, the Gongjindan is containing many materials functioning as anti-oxidation, anti-aging, anti-fatigue, neurotransmitter and immune agent. Moreover, In every water, ethanol, chloroform extracts, the Gongjindan's capability of anti-oxidation is confirmed so that we can apply to patients' treatment clinically.

• Journal of the Korean Applied Science and Technology
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• v.36 no.1
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• pp.13-22
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• 2019

The aim of the present investigation was to assess the oxidation inhibition by nitrogen oxide scavenging activity and physiological activities. Bioactive compound of proanthocyanidin $69.000{\pm}2.737mg$ catechin equivalents (CE)/g dry weight. Antioxidant effects (nitric oxide radical scavenging activity, nitrite scavenging activity, ${\beta}$-carotene bleaching assay and lipid peroxidation inhibition activity) of distilled water (DW), 70% ethanol and n-butanol extract of turmeric (Curcuma longa L.). Turmeric extracts yield were DW 17.11%, 70% ethanol 15.26% and n-butanol 4.12%, respectively. Oxidation inhibition activity of the samples exhibited a dose-dependent increase. However, in the current study, none of the samples evaluated showed activity as strong as the BHA and trolox. Total flavonoid content was the highest in the n-butanol extract, followed by 70% ethanol and DW extract. Further, nitrite scavenging activity was the highest for the n-butanol extract. As a result of this experiment, the turmeric can be utilized as a valuable and potential natural oxidation inhibition for the functional food industry.

• Journal of Microbiology and Biotechnology
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• v.23 no.5
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• pp.719-723
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• 2013

Nitrification in wastewater treatment emits a significant amount of nitrous oxide ($N_2O$), which is one of the major greenhouse gases. However, the actual mechanism or metabolic pathway is still largely unknown. Selective nitrification inhibitors were used to determine the nitrification steps responsible for $N_2O$ emission with activated sludge and enriched nitrifiers. Allylthiourea (86 ${\mu}M$) completely inhibited ammonia oxidation and $N_2O$ emission both in activated sludge and enriched nitrifiers. Sodium azide (24 ${\mu}M$) selectively inhibited nitrite oxidation and it led to more $N_2O$ emission than the control experiment both in activated sludge and enriched nitrifiers. The inhibition tests showed that $N_2O$ emission was mainly related to the activity of ammonia oxidizers in aerobic condition, and the inhibition of ammonia monooxygenase completely blocked $N_2O$ emission. On the other hand, $N_2O$ emission increased significantly as the nitrogen flux from nitrite to nitrate was blocked by the selective inhibition of nitrite oxidation.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.800-807
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• 2001

This study was designed to investigate the antioxidative activity of a substance isolated from. The antioxidative activity of procyanidine was higher than that of dl-tocopherol and BHA on low-density lipoprotein (LDL) oxidation by thiobarbituric acid reactive substance (TBARS). Procyanidine inhibited the copper-mediated oxidation of human LDL in a dose dependent manner with almost complete inhibition at $60{\mu}g/mL$. Procyanidine at a concentration of $80{\mu}g/mL$ in hibited oxidation of LDL induced by J774. LDL oxidized by copper-mediated or cell-induced oxidation was degraded at a much greater rate than native LDL. These results suggested the importance of further research to procyanidine in the investigation of atherosclerosis and free radical-induced injury.

• The Korea Journal of Herbology
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• v.23 no.2
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• pp.123-136
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• 2008

Objectives : To estimate the value of the Gyungokgo as therapeutic agent preventing against aging with an analysis of the ingredients and the bio-activating effects by enzymologic methods. Methods : A quantitative analysis of general ingredients' of the Gyungokgo's extract was done first. The effects on electronic donating ability, SOD-like activity, nitric oxide inhibition, xanthine oxidase inhibition, whitening effect have been investigated in the physiological activity measurement of function experiment. Results : The contained hydrolyzed amino acid is Valine, Aspartic acid, Arginine, Isoleucine and the contained free amino acid is Arginine, Phenylalanine, Valine, Glycine. The derivative of free amino acid is Phosphoserine, Carnocine, ${\gammer}$-Aminoisobutyric acid. And the Gyungokgo contains 14 species of minerals, K>Na>Ca>Mg>Fe>Al>Mn. Then, to assure of the Gyungokgo's anti-oxidation, these following subjects -polyphenol, electronic donating ability, SOD-like activity, nitric oxide inhibition, xanthine oxidase inhibition, tyrosinase inhibation- are analyzed and show high activity especially the most in chloroform extracts, (every ingredients written by the order of high amount) Conclusions : The Gyungokgo contains many materials functioning as anti-oxidation, neurotransmitter, anti-fatigue and immune agent.

• Applied Biological Chemistry
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• v.41 no.4
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• pp.213-217
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• 1998

An assay for cytochrome P450 monooxygenase activity by determination of the products of organophosphate oxidation via inhibition of acetylcholinesterase was described. Extracts from strains of Oryzaephilus surinamensis selected for resistance to chlorpyrifos-methyl (QVOS 102), fenitrothion (VOS F) and malathion (VOS 3), and a standard susceptible strain VOS 48, were incubated with an organophosphate in the presence of a NADPH-generating system and acetylcholinesterase. The degree of inhibition of the acetylchoinesterase activity was converted to manooxygenase activity using standard curves for the inhibition of acetylcholiesterase by chlorpyrifos-methyl-oxon, fenitrooxon and malaoxan. Activity was detectable in VOS 48 and was present at different increased levels with the different organophosphates in the three resistant strains, suggesting that different forms of P450 might be involved in organophosphate oxidation in these insects. The assays were carried out using crude insect homogenates and much smaller samples of insect material than the standard aldrin to dieldrin assay. It should be possible to use the method for determination of monooxygenase activity in single insert.