• 생약학회지
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• 제26권3호
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• pp.265-272
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• 1995

Inhibitory effects of 130 medicinal plants on hyaluronidase activity were analyzed. The medicinal plants are clinically used as herbal medicines for korean traditional prescriptions. Six out of the 130 herbal medicines exhibited more than 50% of inhibition on hyaluronidase activity by their total methanol extracts with 5mg/ml as a final concentration. The active total methanol extracts were prepared from cortex of Acantbopanax gracilistylus, lignum of Caesalpinia sappan, radix of Glycyrrhiza uralensis, radicis cortex of Morus alba, herba of Prunella vulgaris, and radix of Sanguisorba officinalis. These active total methanol extracts were sequentially fractionated with dichloromethane, ethyl acetate, n-butanol, and then water. Among the solvent-fractionated extracts, the butanol fractions of Acantbopanax gracilistylus and Glycyrrhiza uralensis with 1 mg/ml as the final concentration exhibited more than 50% of inhibition on hyaluronidase activity, and the other fractions with the same concentration did less than 20% of inhibition.

• 청정기술
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• 제22권3호
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• pp.161-167
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• 2016

여러 가지 금속이온이 치환된 제올라이트에서 벤젠의 촉매연소 반응에 대해 연구하였다. 사용한 제올라이트 중 Y(4.8)형 제올라이트가 가장 높은 활성을 보여주었고, Y(4.8)형 제올라이트에 치환된 금속 이온 중 구리이온이 가장 높은 활성을 보여주었다. 촉매의 활성은 산소 TPD에 의해 얻어진 흡착산소의 양에 비례하였다. Cu/Y(4.8) 촉매에서 Cu 이온의 농도가 커질수록 반응활성이 증가하였다. 벤젠의 연소반응의 전환율은 반응물 중 벤젠의 농도보다는 산소 농도의 영향을 많이 받았다. 또한, 반응물에 첨가된 물은 촉매 활성을 감소시켰다.

• 대한수의학회지
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• 제23권1호
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• pp.9-16
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• 1983

The effects of ethanol on Na-K-ATPase activity were investigated with cat kidney homogenate. The results were summarized as follows: 1. Na-K-ATPase activity was inhibited with dose-dependent manner by ethanol of higher concentration than 1%, and showed an estimated $I_{50}$ (the inhibitor concentration to cause 50% inhibition) of 7.5%. 2. Hydrolysis of ATP was linear with the incubation time in the absence and presence of 8% ethanol, whereas it was different with preincubation time in the presence of 15% ethanol. 3. Inhibition of Na-K-ATPase activity by ethanol was not affected by increased enzyme concentration, and showed the reversibility of the inhibitory pattern. 4. Kinetic studies of cationic-substrate activation of Na-K-ATPase showed that ethanol had both properties of classical competitive inhibition for $Mg^{{+}{+}}$ or $K^+ and non-competitive inhibition for ATP or $Na^+$. 5. Arrhenius plot yield two break point at $21^{\circ}$ and $30^{\circ}C$ in the absence of ethanol, whereas showing only one break point at $18^{\circ}C$ in the presence of 8% ethanol. These results suggested that ethanol inhibited Na-K-ATPase activity reversible through a disturbance of microenvironment of lipids associated with the enzyme.

• 한국해양바이오학회지
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• 제14권2호
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• pp.143-154
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• 2022

We isolated marine actinomycetes, strain D-5 which produces anti-methicillin resistant Staphylococcus aureus (anti-MRSA) compound. Streptomyces sp. D-5 relatively grew well in the 20~25℃, pH 8.0, and NaCl 3.0%. The ethyl acetate extract of D-5 culture was separated by C₁₈ ODS open column and reverse phase HPLC to yield anti-MRSA compound. The molecular weight of this compound was determined to be 898 by a Liquid chromatograph-mass spectrometer (LC-MS). Compared with penicillin G, this compound showed significant anti-MRSA activity. It also exhibited an inhibition zone of 26 mm at a concentration of 64 ㎍/disk and an inhibition zone of 16 mm at a concentration of 16 ㎍/disk against the MRSA KCCM 40511. Furthermore, the co-treatment of HPLC peak 5 compound and vancomycin caused a more rapid decrease in MRSA cells than each compound alone. It showed 86.8% growth inhibition activity within 12 hours at a low concentration of 50 ㎍/mL during co-treatment, and 97.1% growth in-hibition activity within 48 hours against MRSA KCCM 40511. Taken together, our results suggest that Streptomyces sp. D-5 and its anti-MRSA compound could be employed as a potent agent in MRSA infection.

• Journal of the Korean Wood Science and Technology
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• 제45권6호
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• pp.809-827
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• 2017

Steam explosion was applied to extract phenolic compounds from oak wood (Quercus mongolica). The effects of three independent factors (ethanol concentration, extraction temperature and extraction time) on the total phenolic content, DPPH radical scavenging activity, and antimicrobial activity from the steam exploded oak wood were optimized using response surface methodology (RSM). The independent variables were coded at three levels and their actual values were selected on the basis of preliminary experimental results. The following optimal extraction conditions were selected: ethanol concentration 82.0%, extraction temperature $71.7^{\circ}C$, and extraction time 60.5 min for total phenolic content; ethanol concentration 78.3%, extraction temperature $70.3^{\circ}C$, and extraction time 57.6 min for DPPH radical scavenging activity; ethanol concentration 80.6%, extraction temperature $68.4^{\circ}C$, and extraction time 59.0 min for antimicrobial activity. The experimental values agreed with those were predicted within confidence intervals indicating the suitability of RSM in optimizing the ethanol extraction of phenolic compounds from the steam exploded oak wood. Under the optimized conditions, the experimental value of the total phenolic content was 111.8 mg GAE/g dry steam exploded oak wood, DPPH free radical scavenging activity was 65.7%, and antimicrobial activity was 17.0 mm, and those are reasonably close to the predicted values (109.2 mg GAE/g dry steam exploded oak wood, 62.3% and 15.9 mm, respectively).

• 약학회지
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• 제43권6호
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• pp.809-817
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• 1999

The effect of 2-(4-cyanophenyl)amino-1,4-naphthalenedione-3-pyridinium perchlorate (PQ5) on pla-telet aggregation and its action mechanisms were investigated with rat platelet. PQ5 inhibited the platelet aggregation induced by collagen ($6{\;}{\mu\textrm{g}}/ml$), thrombin (0.4 U/ml) and A23187 ($3{\mu}M$) in concentration-dependent manner with $IC_{50}$ values of 5.50, 25.89 and $37.12{\;}{\mu}M$, respectively. PQ5 also significantly reduced the thromboxane $A_2$ (TXA2) formation in a concentration dependent manner. The collagen-induced arachidonic acid (AA) release in [-3H]-AA incorporated platelet, an indication of the phospholipase $A_2$ activity, was decreased by PQ5 pretreatment PQ5 significantly inhibited the activity of thormboxane synthase only at high concentration ($100{\mu}M$), but did not affect the cyclooxygenase activity at all. Collagen-induced ATP release was significantly reduced by PQ5. Calcium-induced platelet aggregation experiment suggests that the elevation of intracellular free $Ca^{2+}$ concentration ($[Ca^{2+}]_i$) by collagen stimulation is decreased by the pretreatment of PQ5, which is due to the inhibition of calcium release from intracellular store and influx from outside of the cell. PQ5 did not showed the effect of anticoagulation as prothrombin time (PT) or activated partial thromboplastin time (APTT). Form these results, it is suggested that PQ5 exerts its antiplatelet activity through the inhibition of the intracellular $Ca^{2+}$ mobilization and the decrease of the $TXA_2$ synthesis.

• KSBB Journal
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• 제26권2호
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• pp.151-156
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• 2011

For the development of functional food and cosmetics using the hot water extract of Undaria pinnatifida, the concentrations of vitamin, amino acid and element and activities of antioxidant and nitrite scavenging were investigated. The results are shown as follows: Vitamin C and E concentrations were 0.301 and 0.11 mg/100 g, respectively. Mineral concentrations were an order of Ca > Mg > K > Fe. The concentrations of total amino acids were an order of Glu > Ala > Val > Leu > Gly > Pro. Total phenol concentration and DPPH radical scavenging activity were increased with the increase of the concentration of extract. Especially, when the extract concentrationwas increased from 1.0 to 10.0 mg/mL, the total phenol concentration was increased from 0.043 to 0.125 OD 725 nm. DPPH radical scavenging activity at 50 mg/mL was 70.1%. The antioxidant activity of extract was stable in range of 80 to $140^{\circ}C$ and pH 3-9. The nitrite scavenging activity was increased with the decreaseof pH and the increase of it's extract concentration. Especially, it was 83.4% at 50 mg/mL (pH 1.2). These results showed that the hot water extract of U. pinnatifida can be applied to functional food and cosmetics.

• 대한본초학회지
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• 제33권6호
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• pp.29-34
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• 2018

Objectives : It is necessary to manage herbal medicines based on effectiveness by comparing the efficacy of herbal medicines by region. In this study, we compared anti-oxidative activity and marker compounds of Eucommiae Cortex by regional groups. Methods : Eucommiae Cortex grown and harvested in Gangjin, Sancheong, Yeongwol, Jangsu, and Jecheon were used. Eucommiae Cortex was extracted in distilled water at $100^{\circ}C$ for 3 hours, and filtered. filtered. Extract samples were freeze-dried at $-80^{\circ}C$. Comparison of anti-oxidant activity in Eucommiae Cortex samples from regional groups was measured in 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) free radical scavenging, and ferric reducing antioxidant power (FRAP) between regional groups of Eucommiae Cortex. In addition, high-performance liquid chromatography (HPLC) analysis was conducted to compare pinoresinol diglucoside concentration by regional groups. Results : HPLC analysis found that pinoresinol diglucoside concentration, widely known as the marker compound of Eucommiae Cortex, was the highest in Gangwon Yeongwol. There was a significant difference in anti-oxidative activity of Eucommiae Cortex between regional groups as discovered in DPPH, ABTS and FRAP assays. DPPH free radical scavenging was the highest in Jeonbuk Jangsu. ABTS free radical scavenging was the highest in Jeonbuk Jangsu and Chungbuck Jecheon. FRAP was the highest in Jeonbuk Jangsu. Conclusions : Although pinoresinol diglucoside concentration was high, anti-oxidative activity was not proportionately high. Pinoresinol diglucoside concentration was the highest in Gangwon Yeongwol. Anti-oxidative activity was the highest in Jeonbuk Jangsu.

• 한국수소및신에너지학회논문집
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• 제33권4호
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• pp.343-352
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• 2022

Co/Al₂O₃ nanopowder was used as a catalyst to investigate the effect of catalyst support, reduction temperature, sodium borohydride (NaBH₄) concentration, sodium hydroxide (NaOH) concentration, and reaction temperature on the characteristics of NaBH₄ hydrolysis. The Co/Al₂O₃ nanopowder showed a high catalytic activity among various catalysts. Catalyst reduction at 250℃ exhibited a relatively good activity. The activity decreased with an increase in the NaBH₄ concentration. Conversely, the activity increased and then decreased with an increase in the NaOH concentration. Additionally, the activity increased with an increase in the reaction temperature. The value of apparent activation energy was 40.81 kJ/mol, which was lower than the other Co-based catalysts. Thus, Co/Al₂O₃ nanopowder catalyst can be widely used for NaBH₄ hydrolysis owing to its superior catalytic activity.

• The Korean Journal of Physiology and Pharmacology
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• 제9권4호
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• pp.209-213
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• 2005

Interstitial cells of Cajal (ICCs) are the pacemaker cells that generate slow waves in the gastrointestinal (GI) tract. In the present study, we investigated the effect of mitochondrial ATP-sensitive potassium (mitoKATP) channel on pacemaking activity in cultured ICCs from murine small intestine by using whole-cell patch clamp techniques. Under current clamp mode, at 10μM glibenclamide, there was no change in pacemaking activity of ICCs. At $30{\mu}M$ glibenclamide, an inhibitor of the ATP sensitive $K^+$ channels, we could find two examples. If pacemaking activity of ICCs was irregulating, pacemaking activity of ICCs was changed into regulating and if in normal conditions, membrane potential amplitude was increased. At $50{\mu}M$ glibenclamide, the resting membrane potential was depolarized. At 3mM 5-HDA, an inhibitor of the mitoKATP channels, inhibited the pacemaking activity of ICCs. Both the amplitude and the frequency were decreased. At 5 mM 5-HDA, both the amplitude and the frequency were completely abolished. Diazoxide, an opener of the mitoKATP channels, was applied to examine its effect on pacemaking activity of ICCs. At $50{\mu}M$ concentration, the pacemaking activity of ICCs was inhibited. Both the amplitude and the frequency were decreased. At 1 mM concentration, both the amplitude and the frequency were completely abolished and the resting membrane potential was shaked.These results indicate that mitoKATP channel has an important role in pacemaking activity of ICCs.