• 대한안전경영과학회지
• /
• 제17권3호
• /
• pp.343-353
• /
• 2015

The purpose of this study includes: Firstly, to examine the effects of corporate entrepreneurship on market orientation, radical innovation, and organizational performance. Secondly, to examine the mediating effect of the market orientation, radical innovation on the relationship between corporate entrepreneurship and organizational performance. In order to verify the relationships and mediating effect, data were collected from convenient sample of 269 employees at small and medium enterprises in Busan, Ulsan, Gyeongju city to test theoretical model and its hypotheses. All data collected from the survey were analyzed using with SPSS 18.0 and AMOS 18.0. This study reports findings as followed: first, the relationship between the corporate entrepreneurship and the market orientation is positively related. Second, there was also a positive correlation between the corporate entrepreneurship and the radical innovation. Third, there was also a positive correlation between the market orientation and the radical innovation. Fourth, the relationship between the market orientation and the organizational performance is positively related. Fifth, there was also a positive correlation between the corporate entrepreneurship and the organizational performance. Sixth, there was also a positive correlation between the radical innovation and the organizational performance. Finally, the market orientation played as a partial mediator on the relationship between corporate entrepreneurship and radical innovation. The market orientation and radical innovation played as a partial mediator on the relationship between corporate entrepreneurship and organizational performance. Also, the radical innovation played as a partial mediator on the relationship between market orientation and organizational performance. Based on these findings, the limitations of the study and some directions for future studies were presented.

• Bulletin of the Korean Chemical Society
• /
• 제35권11호
• /
• pp.3143-3155
• /
• 2014

This tutorial review provides a general account of the electrochemical behavior of quinones and their various applications. Quinone electrochemistry has been investigated for a long time due to its complexity. A simple point of view is developed that considers the relative stability of the reduced quinone species and the values of the first and second reduction potentials. The 9-membered square scheme in buffered aqueous solutions is explained and semiquinone radical stability is discussed in this context. Quinone redox reaction has also been employed in various studies. Diverse examples are presented under three broad categories defined by the roles of quinone: molecular tool for physical chemistry, versatile electron mediator, and charge storage for energy conversion devices.

• Biomolecules & Therapeutics
• /
• 제9권3호
• /
• pp.188-193
• /
• 2001

Free radical scavengers or quenching agents for reactive oxygen species (ROS) present in consumable fruits, vegetables, and beverages have received considerable attention as potential antioxidants, and thus uses for treatment of several human diseases. In this study, grapevine shoot extract (GSE) containing high concentration of resveratrol and viniferine was evaluated for antioxidant potential and inhibition of pro-inflam-matory mediator production. Utilizing 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity and xanthine oxidase (XOD) inhibition assay the GSE showed inhibitory effects of DPPH radical scavenging and XOD activity with the $IC_{50}$/ values of 34.5 and 155 $\mu\textrm{g}$/ml, respectively. In addition, GSE also exhibited the inhibition of prostaglandin E$_2$ (PGE$_2$) and nitric oxide (NO) production in lipopolysaccharide (LPS)-induced mouse macrophage RAW264.7 cells with the $IC_{50}$/ value of 6.4 and 14.5 $\mu\textrm{g}$/ml, respectively. This result suggests that grapevine shoot extract has the potential activity as a natural antioxidant or antiinflammatory agent.

• KSBB Journal
• /
• 제16권2호
• /
• pp.179-182
• /
• 2001

Horseradish peroxidase(HRP) 및 $H_2O_2$. 와 함께 2, $2^+$-azinobis (3-ethylbenzthiazoline-6-sulfonic acid)(ABTS)블 라디 칼 전달체로서 사용하면 kraft 펄프의 표백효율이 증가하였다. 이때 반 응에 사용할 수 있논 $H_2O_2$의 농도는 약 20 mM까지 증가시킬 수 있었다 Kraft 펄프의 표백효율은 효소의 사용량을 0 0.3 mg/90 mL 까지, ABTS의 농도를 2 mM 까지 높일수록 증가하였으나 이후에는 더 이상 증가하지 않았다. 또한 HRP 에 의한 펄프표백 효율은 효소의 활성 및 펄프에의 홉착강도 와 멸접한 관련이 있었다. HRP의 활성과 kraft 펼프의 표백 효율은 pH 7에서 가장 높았으며 산성용액과 암쌀려성 용액 에서는 강소하였다. 또한 HRP의 펄프홉착 강도는 pH 6-8에 서 가장 낮았고 산성용액(pH 5) 및 알칼리성 용액(pH 9)에서 가장 높았다 펼프의 주요구성 성분인 결정형 셀룰로즈와 려 그닌 중 려그년에 대한 효소의 흡착강도가 더욱 높았다.

• Natural Product Sciences
• /
• 제16권2호
• /
• pp.111-115
• /
• 2010

Anti-inflammatory and anti-oxidant effect of Spirodela polyrrhiza (Lemnaceae), a widely used traditional medicinal plant were investigated. In macrophages nitric oxide (NO) is released as an inflammatory mediator and has been proposed to be an important modulator of many pathophysiological conditions including inflammation. 85% MeOH extracts of S. polyrrhiza (0.01, 0.1, 1 mg/mL) suppressed nitric oxide production in interferone-$\gamma$ (IFN-$\gamma$) and lipopoloysaccharide(LPS)-stimulated macrophages. It also attenuated the expression of inflammatory enzymes like inducible NOS (iNOS) and cyclooxygenase-2(COX-2) as assessed by immunoblotting with specific antibodies. Moreover, the values obtained with DPPH radical, superoxide anion and NO radical scavenging assay showed that S. polyrrhiza has potent antioxidant properties as a natural ROS scavenger. The results of the present study suggest the potential use of S. polyrrhiza in the treatment of ROS-mediated chronic inflammatory diseases such as atherosclerosis and rheumatoid arthritis.

• Korean Journal of Acupuncture
• /
• 제29권3호
• /
• pp.406-420
• /
• 2012

Objectives : Scutellaria barbata has been widely used in oriental medicine used for treatment of acute and chronic inflammatory diseases. In this study, to investigate the protective effect of Scutellaria barbata on type I allergic response, we determined whether Scutellaria barbata inhibits early or late allergic responses. Methods : To assess the effect of Scutellaria barbata Pharmacopuncture Extract(SB) in RBL-2H3 cells, we investigated the levels of the markers of degranulation such as ${\beta}$-hexosaminidase and histamine, inflammatory mediator such as IL-4, TNF-${\alpha}$, PGE2 and cysLT, and mRNA expression of cytokines and enzymes. In addition, we determined the levels of intracellular ROS by DCFH-DA assay and the free radical scavenging activity by DPPH method. Results : We found that SB suppressed the release of ${\beta}$-hexosaminidase and histamine and the production of IL-4, TNF-${\alpha}$, PGE2 and cysLT in RBL-2H3 by the antigen stimulation. SB also significantly inhibited the enzyme mRNA expressions, such as HDC2, COX-1, COX-2, 5-LOX and iNOS2, along with reduced cytokine mRNA expressions, such as IL-$1{\beta}$, IL-2, IL-3, IL-4, IL-5, IL-6, IL-13, TNF-${\alpha}$ and GM-CSF in RBL-2H3. In addition, SB suppressed the levels of intracellular ROS. Conclusions : Our results indicate that SB protects against type I allergic response and exert an anti-inflammatory effect through the inhibition of degranulation, inflammatory mediator release and mRNA expression of cytokines and enzymes.

• 한국식품과학회지
• /
• 제35권1호
• /
• pp.132-137
• /
• 2003

국내에서 생산된 거봉 및 캠벨 포도의 씨, 줄기 및 껍질 추출물에 대하여 항산화 작용, 염증 관련 인자 생성에 미치는 활성 및 암세포 성장에 대한 영향 등을 resveratrol과 비교하여 평가하였다. 그 결과 포도 추출물 중 거봉줄기, 캠벨줄기, 캠벨씨 및 거봉씨 추출물들이 항산화 능력을 나타내었고 그 중 거봉씨 추출물은 vitamin C와 효력이 유사하게 나타나 항산화 효능이 우수함을 알 수 있었다. 또한 마우스 대식세포주인 RAW 264.7 cell을 이용하여 포도 추출물들의 LPS처리에 의한 $PGE_2$ 및 NO 생성을 저해 여부를 확인한 결과, 거봉줄기, 거봉씨, 및 캠벨씨 추출물이 $50\;{\mu}g/mL$에서 $PGE_2$ 및 NO 생성을 50% 가량 저해하는 효능을 나타내었다. 또한 사람 폐암 및 대장암 세포주를 이용하여 포도 추출물들이 암세포 성장 저해 효과를 나타내는지를 확인하였는데 거봉줄기 및 씨 추출물 $50\;{\mu}g/mL$에서 30% 정도의 암세포 성장 저해 작용을 나타내었다.

• 대한약리학회지
• /
• 제21권1호
• /
• pp.12-26
• /
• 1985

흰쥐 뇌 미토콘드리아에 의한 $O^{-}_{2}{\cdot}$ 의 생성과 이 radical의 유해작용 및 그 작용기전을 알아보기 위하여 본실험을 수행하였다. Succinate와 antimycin존재하에서 미토콘드리아는 $O^{-}_{2}{\cdot}$을 생성하였으며 이는 SOD-inhibitable NBT환원으로 확인되었다. 동일 조건에서 $H_2O_2$는 일차생성물인 $O^{-}_{2}{\cdot}$의 dismutation으로 생성됨을 알수 있었다. 상기조건에서 미토콘드리아의 막지질이 파괴되었고 반응액에 첨가된 isocitrate dehydrogenase와 적혈구에 각각 불활성화와 용혈이 초래되었다. 이같은 작용은 $Fe^{++}$이 있을때만 관찰 되었다. 그리고 독작용은 superoxide dismutase 혹은 castalase에 의해서 억제되었다. 또한 methional을 첨가하였을 때 ethylene이 생성되었으며 그 생성은 $Fe^{++}$에 의하여 현저히 증가하였다. Ethylene 생성 역시 상기 효소에 의하여 억제되었다. 따라서 미토콘드리아에서 발생된 $O^{-}_{2}{\cdot}$은 거대분자 및 세포에 독성을 나타낼수 있으며 이같은 작용은 $Fe^{++}$의 촉매작용에 의한 $O^{-}_{2}{\cdot}$와 $H_2O_2$의 상호작용으로 발생되는 $OH{\cdot}$ 에 의한것으로 추측되었다. 이상의 결과는 미토콘드리아가 유독성 산소 radical을 발생하므로 조직손상을 시킬 수 있다는 가능성을 시사하는 증거라고 생각되었다.

• 한국식품영양학회:학술대회논문집
• /
• 한국식품영양학회 2000년도 춘계학술심포지엄
• /
• pp.13-20
• /
• 2000

Melatonin, a chemical mediator produced in the mammalian pineal gland and several other organ, is a ubiquitously acting antioxidant. It has been shown to scavenge the hydroxyl radical (ㆍOH), singlet oxygen ($^1$O$_2$) and the peroxynitrite anion (ONOO-). In addition, melatonin reportedly stimulates a number of antioxidative enzymes including glutathione peroxidase, glutathione reductase and glucose-6-phosphate dehydrogenase. Antioxidative effect of melatonin in pharmacological and physiological level was investigated using hepatocarcinogen 2-nitropropane (2-NP) and pinealectornized (Px) rats, respectively. Lipid peroxidation (LPO) as indicated by malondialdehyde and 4-hydroxyalkenals and DNA damage as indicated by 8-hydroxydeoxyguanosine (8-OH-dG) induced by 2-NP were prevented by melatonin. The degree of LPO and DNA damage in Px rats were higher than those of intact old and young ones suggesting the removal of pineal gland resulted in higher accumulation of oxidative damage.

• 동의생리병리학회지
• /
• 제23권4호
• /
• pp.853-859
• /
• 2009

Nardostachys chinensis has been used widely as a traditional medicine for the treatment of diverse diseases. The dried plant was extracted with 85% methanol extract (NC). We investigated the antioxidant properties of NC on the 1,1-diphenyl-2-picryhydrazyl (DPPH) radical, superoxide anion and nitric oxide radical scavenging capacity under in vitro assays. NC showed potent antioxidant activity, compared to ascorbic acid. In macrophages, nitric oxide is released as an inflammatory mediator and has been proposed to be an important modulator of many pathophysiological conditions in inflammation. In the present study, it was also investigated that the inhibition effects on NO and the mechanism of down-regulation of immune response by NC in IFN-IFN-$\gamma$/LPS-stimulated mouse (C57BL/6) peritoneal macrophages. Extracts of NC suppressed NO production and the expression of iNOS and COX-2. The present results indicate that NC has an antioxidant and anti-inflammatory properties and therefore may be beneficial in diseases which related to oxidative stress-mediated chronic inflammatory disorders.