• Korean Journal of Environmental Agriculture
• /
• v.3 no.2
• /
• pp.16-22
• /
• 1984

This study was carried out to investigate the stability of dinobuton (2-sec-butyl-4,6-dinitrophenyl isopropyl carbonate) in distilled water and buffer solutions and its persistence in soils. When dinobuton was incubated at $30^{\circ}C$ and $60^{\circ}C$ in distilled water, the half-lives of dinobuton was 28 and 6 days, respectively. The decomposition of dinobuton was, therefore, faster at high temperature than at low temperature. The half-life of dinobuton was about 27 days in the acidic solution $(pH\; 4{\sim}6)$, whereas 10 and 4 days in the alkaline solutions of pH 9, and 10, respectively. Thus dinobuton was stable in acidic solution, and unstable in alkaline solution. Dinoseb (2-sec-butyl-4,6-dinitrophenol), which is produced in the degradation process of dinobuton, was produced in small amounts in distilled water and buffer solutions. The half-life of dinobuton in sterilized soil was about 16 days longer than in non-sterilized soil. Dinoseb was also more persistent in sterilized soil than in non-sterilized one.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.17 no.2
• /
• pp.115-124
• /
• 1988

This study was carried out to realize the effect of gibberllic acid$(GA_3)$, 1-naphthaleneacetic acid(NAA) and indole-3-acetic acid(IAA) on the biosynthesis of vitamin C. The relation between carbohydrate metabolism and vitamin C production in soybean sprouts was also investigated. Growth, vitamin C content, protein, galactonolactone dehydrogenase(GLD), ribulose diphosphate carboxylase(RuDpCO) and RNA level in the plastid and cytoplasm were determined. The effects of protein and respiratory inhibitors on the growth and vitamin C production were also examined. The most favourable growth of soybean sprouts was observed at the level of NAA $10^{-8}M,\;IAA10^{-6}M\;and\;GA_3\;10^{-5}M$ in the single treatment, respectively, and also favourable at levels of $GA_3\;10^{-5}M+NAA\;10^{-9}M\;and\;GA_3\;10^{-5}M+IAA\;10^{-9}M$ in the case of mixed treatment. The excellent growth was observed at the level IAA $10^{-6}M$ among all the single and mixed treatments. When the soybean sprouts were treated with NAA $10^{-8}M,\;IAA\;10^{-6}M\;GA_3\;10^{-5}M,\;GA_3\;10^{-8}M+IAA\;10^{-6}M,\;and\;GA_3\;10^{-5}M+IAA\;10^{-9}M$, the maximum growth rate was observed at the level of IAA $10^{-6}M$ and the conten of vitamin C was 24.26mg% which was 1.6 times higher than that of the control. RuDpCO was inhibited by the chloramphenicol at the concentration that did not inhibit the growth but the activities of NADP-GDH, GLD and vitamin C content were not affected. These results showed that the biosynthesis of viamin C had nothing to do with the activity of chloroplastic RNA but with cytoplasm. The highest vitamin C content was found at the the level of IAA $10^{-6}M$, where the GLD activity increased up 1.8 times of the control. The concentration of IAA $10^{-6}M$ promoted the biosynthesis of RNa and protein both in chloroplast and cytoplasm, especially in the cytoplasm. Thus it suggeted that IAA affected vitamin C biosynthesis by regulating RNA level in the cytoplasm. 2,4-Dinitrophenol as an uncoupler of oxidative phosphorylation did not inhibit the vitamin C biosynthesis, however, all of the respiratory inhibitors severely inhibited the growth and vitamin C biosynthesis.

• Microbiology and Biotechnology Letters
• /
• v.10 no.1
• /
• pp.1-7
• /
• 1982

A Rhizopus sp. was selected for its strong cellulolytic activity among various strains of molds found in rotting ginseng roots. Studies were made on some properties of the cellyloiytic enzyme produced by the strain. The results obtained were summarized as follows: The optimum pH of the enzyme was 4.5 and the range of its stability to the pH was 3.0 to 7.0. The optimum temperature was 5$0^{\circ}C$, while the enzyme was instantly inactivated above 6$0^{\circ}C$. Mn$^{＋＋}$ and Co$^{＋＋}$ ions increased enzyme activity and the metal ions were found to increased the ther-mostability of the enzyme. This enzyme was inhibited by sodium dodecyl sulfate and 2,4-dinitrophenol. This enzyme had a strong cellulolytic enzyme activity on various native cellulose given a sufficient reaction time. The addition of 0.5% saponin solution into reaction mixture increased the enzyme activity.

• The Korean Journal of Mycology
• /
• v.17 no.2
• /
• pp.99-104
• /
• 1989

Effects of organic compounds, photosensitizers and influx of metal ions on the light-induced mitochondrial ATP synthase in Lentinus edodes purified by stepped sucrose density gradient centrifugation were studied. In our previous work, the activation wavelength and the illumination time of mitochondrial ATP synthase were 470 nm and 15 sec, respectively. This enzyme was activated 85% by 1 mmole 2,6-dichlorophenol indopheol and inhibited by 1 mmole 2,-4-dinitrophenol, $10\;{\mu}mole$ 2-heptyl-4-hydroxyquinoline-N-oxide and $100\;{\mu}g$ oligomycin per ml of ethanol. Particularly, the enzyme was activated 414% by 10 mmole phenazine methosulfate as photosensitizer at 470 nm light. In the influx effects of $Fe^{3+}$ and $Fe^{2+}$ ion, the activity of the above enzyme increased under the optimal light condition compared with nonillumination state.

• Journal of Applied Biological Chemistry
• /
• v.50 no.4
• /
• pp.281-287
• /
• 2007

Microorganisms were isolated from earthworm intestine and examined for their ability to degrade 3-methyl-4-nitrophenol (MNP), a main degradation product of the insecticide fenitrothion. An isolate that showed the best degradation of MNP was selected for further study. The 16S rRNA analysis showed that the isolate belongs to the genus of Burkholderia, close to phenanthrene-degrading Burkholderia sp. S4.9, and is named Burkholderia sp. SH-1. When time-course degradation of MNP by SH-1 was examined by high performance liquid chromatographic analysis, almost complete degradation of MNP was observed within 26 h. Colony forming unit value assays indicated that the isolate SH-1 was capable of utilizing MNP as a sole carbon source. SH-1 could also degrade p-nitrophenol (PNP) but could not degrade ortho-substituted nitroaromatics such as 2,4-, 2,6- and 2,5-dinitrophenol. Catechol was detected as the main degration product of MNP and PNP. SH-1 was also found in the soil from which earthworms were obtained. These results suggest that the dispersal of Burkholderia sp. SH-1 into different environment with the aid of earthworms is likely to play a role in bioremediation of the soil contaminated with MNP.

• YAKHAK HOEJI
• /
• v.43 no.6
• /
• pp.851-860
• /
• 1999

The effects of antimycin A(AA), dodium azide ($NaN_3$) and 2,4-dinitrophenol (DNP), which inhibit mitochondrial ATP production, on cellular functions of cultured astrocytes were studied. High concentrations of AA $(50{\;}\mu\textrm{g}/ml),{\;}NaN_3$ (100mM) and DNP (20mM) significantly decreased 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) reduction, which was known to be related to mitochondrial function and then cel viability. AA ($50{\;}\mu\textrm{g}/ml$) increased lactate dehydrogenase (LDH) release and decreased [$^3H$] glutamate uptake, suggesting severe damage of cellular function by the concentrations of the compounds. Meanwhile, low concentrations of AA $(\leq{;\}10{\;}\mu\textrm{g}/ml),{\;}NaN_3{;\}(\leq{\;}50mM)$ and DNP ($\leq{\;}5mM$) significantly increased MTT reduction, the effect of which was specific to astrocytes. AA (5 and $10{\;}\mu\textrm{g}/ml$) did not affect LDH release and [$^3H$] glutamate uptake, indicating that these compounds increased MTT reduction at the low concentrations without cellular membrane damage. However, the low concentrations of AA produced significant decrease of MTT reduction in a glucose-free medium. Low concentrations of AA (1 and $5{\;}\mu\textrm{g}/ml$) did not change ATP production of astrocytes in the medium containing 10 mM glucose, but completely inhibited in a glucose-free medium, suggesting marked increase of cytosolic ATP production by the blockade of mitochondrial ATP production with low concentrations of AA. These results suggest that astrocytes have ability to enhance neuronal function or survival under conditions of incomplete ischemia or early by enhancement of glycolysis, and that cellular reduction of MTT occurs not only mitochondrially but also extramitchondrially.

• The Korean Journal of Physiology and Pharmacology
• /
• v.1 no.6
• /
• pp.741-748
• /
• 1997

In the present study, we have investigated the effect of metabolic inhibition on the inward rectifier K current ($I_{K1}$). Using whole cell patch clamp technique we applied voltage ramp from +80 mV to -140 mV at a holding potential of -30 mV and recorded the whole cell current in single ventricular myocytes isolated from the rabbit heart. The current-voltage relationship showed N-shape (a large inward current and little outward current with a negative slope) which is a characteristic of $I_{K1}$. Application of 0.2 mM dinitrophenol (DNP, an uncoupler of oxidative phosphorylation as a tool for chemical hypoxia) to the bathing solution with the pipette solution containing 5 mM ATP, produced a gradual increase of outward current followed by a gradual decrease of inward current with little change in the reversal potential (-80 mV). The increase of outward current was reversed by glibenclamide ($10\;{\mu}M$), suggesting that it is caused by the activation of $K_{ATP}$. When DNP and glibenclamide were applied at the same time or glibenclamide was pretreated, DNP produced same degree of reduction in the magnitude of the inward current. These results show that metabolic inhibition induces not only the increase of $K_{ATP}$ channel but also the decrease of $I_{K1}$. Perfusing the cell with ATP-free pipette solution induced the changes very similar to those observed using DNP. Long exposure of DNP (30 min) or ATP-free pipette solution produced a marked decrease of both inward and outward current with a significant change in the reversal potential. Above results suggest that the decrease of $I_{K1}$ may contribute to the depolarisation of membrane potential during metabolic inhibition.

• Nutrition Research and Practice
• /
• v.6 no.2
• /
• pp.97-105
• /
• 2012

$Schizandra$ $chinensis$ Baillon is a traditional folk medicine plant that is used to treat and prevent several inflammatory diseases and cancer in Korea, but the underlying mechanisms involved in its anti-allergic activity are not fully understood. This study was designed to investigate mechanisms of anti-allergic activity of a $Schizandra$ $chinensis$ Baillon water extract (SCWE) in immunoglobulin E (IgE)-antigen complex-stimulated RBL2H3 cells and to assess whether gastric and intestinal digestion affects the anti-allergic properties of SCWE. Oxidative stress is an important consequence of the allergic inflammatory response. The antioxidant activities of SCWE increased in a concentration-dependent manner. RBL-2H3 cells were sensitized with monoclonal anti-dinitrophenol (DNP) specific IgE, treated with SCWE, and challenged with the antigen DNP-human serum albumin. SCWE inhibited ${\beta}$-hexosaminidase release and expression of interleukin (IL)-4, IL-13, and tumor necrosis factor-alpha (TNF-${\alpha}$) mRNA and protein in IgE-antigen complex-stimulated RBL2H3 cells. We found that digested SCWE fully maintained its antioxidant activity and anti-allergic activity against the IgE-antigen complex-induced activation of RBL-2H3 cells. SCWE may be useful for preventing allergic diseases, such as asthma. Thus, SCWE could be used as a natural functional ingredient for allergic diseases in the food and/or pharmaceutical industries.

• Journal of Microbiology and Biotechnology
• /
• v.15 no.2
• /
• pp.412-420
• /
• 2005

In order to investigate factors affecting the denitrification in the F-STEP PROCESS using a loess ball as support media and Pseudomonas DWC 17-8, calcining temperature, loess ball size, pH, nitrate concentration, working temperature, and inhibitor were studied in batch mode using synthetic sludge. A 5- 10 mm of loess ball (960$^{circ}$ of calcining temperature) was the most suitable for denitrification. When the initial pH was increased from 3.0 to 7.0, the removal efficiency of nitrate was increased. Specifically, at initial pH of 7.0, the maximum removal efficiency of nitrate was 5.0 mg/min. When the initial concentration of nitrate was increased from 100 to 400 mg/l, the removal efficiency of nitrate was proportional to the concentration of nitrate. The maximum removal efficiency of nitrate was 5.72 mg/min at 400 mg/l of initial concentration. When the operating temperature was increased from 10 to 30$^{circ}$, the removal efficiency of nitrate was increased from 0.76 to 6.15 mg/min, and at above 40$^{circ}$ of operating temperature, it was decreased from 4.0 to 2.0 mg/min. Among the various inhibitors, higher than 10$^{-1}$ M of sodium azide abolished this reaction completely. When the KCN concentration was above 10$^{-1}$ M, the reaction was inhibited completely. In the case of 2,4-dinitrophenol and sodium sulphide, it was inhibited at above 10$^{-2}$ M completely. For testing the various flow orders of the F-STEP PROCESS for effective denitrification using practical wastewater, continuous experiments under the optimum conditions were carried out for 60 days. Among the various processes, the PROCESS A gave the highest efficiencies of denitrification, nitrification, and total nitrogen (TN) removal with 86.5, 89.5, and $90\%$, respectively. For scale-up in the PROCESS A, real farm wastewater was used and pilot tests carried out for 90 days. The denitrification efficiency was $97.5\%$, which was increased by $12.7\%$. The efficiencies of TN removal and nitrification were 96.6 and $70.0\%$, respectively. The removal efficiency of chemical oxygen demand (COD) was $63.7\%$, which was increased by $20\%$.

• The Korean Journal of Physiology
• /
• v.26 no.1
• /
• pp.55-68
• /
• 1992

The effects of changes in extracellular $Na^+\;and\;Ca^+$ concentration on the membrane potential and contractility were studied in the antral circular muscle of guinea pig stomach in order to elucidate the existence and the nature of $Na^+/Ca^{2+}$ exchange mechanism. All experiments were performed in tris buffered Tyrode solution which was aerated with 100% $O_2$ and kept at $35^{\circ}C.$ The treatment of $10^{-5}$ ouabain was performed to induce intracellular $Na^+$ loading prior to the start of experiment. The results were as follows: 1. $Na^+$-free Tyrode or high $Ca^{2+}$-Tyrode solution hyperpolarized the membrane potential and induced contracture. The time course of contracture was similar to that of change in membrane potential. 2. The degree of hyperpolarization and the amplitude of contracture decreased in accordance with the increase of extracellular $Na^+$ concentration. 3. $Na^+$-free contracture was developed even after blocking the influence of intrinsic nerves by the pretreatment with atropine, guanethidine and TTX. 4. $Ca^{2+}$-channel blockers(D-600 or $Mn^{2+}$) and the blocker of intracellular $Ca^{2+}$ release from sarcoplasmic reticulum(ryanodine) did not suppress the development of $Na^+$-free contracture. And also, dinitrophenol had no effect on $Na^+$-free contracture. 5. Dose-response relationship between extracellular $Na^+$ concentrations and the magnitude of contractures showed a sigmoid pattern. The slope of straight line from Hill plot was 2.7. 6. In parallel with the increase of extracellular $Ca^{2+}$ concentration, the amplitude of contracture increased dose dependently and was maximum at 8 mM $Ca^{2+}$-Tyrode solution. 7. The relationship between extracellular $Ca^{2+}$ concentrations and the magnitude of contractures showed hyperbolic pattern. The slope of straight line from Hill plot was 1.1. From the above results, it is suggested that $Na^+/Ca^{2+}$ exchange mechanism exists in the antral circular muscle of guinea pig stomach and this mechanism affects the membrane potential electrogenically.