• Title/Summary/Keyword: Structural activity

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Antioxidant Activity Resveratrol Closely Correlates with Its Monoamine oxidase-A Inhibitory Activity

  • Han, Yong-Nam;Ryu, Shi-Yong;Han, Byng-Hoon
    • Archives of Pharmacal Research
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    • v.13 no.2
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    • pp.132-135
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    • 1990
  • Polyhydroxystilbenes including resveratrol were reported to competitively inhibit monoamine oxidase-A-without structural relation with substrates and cynthetic inhibitors for the enzyme. We attempt to explore a plausible mechanism for their inhibitory activity on MAO-A. All the polyhydroxystilbenes tested showed the antioxidant activity on liver homogenate. Furthermore, the antioxidant activity turned out to closely correlate with the MAO-A inhibitory activity.

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Molecular Characterization of the Recombinant A-chain of a Type II Ribosome-Inactivating Protein (RIP) from Viscum album coloratum and Structural Basis on its Ribosome-Inactivating Activity and the Sugar-binding Properties of the B-chain

  • Ye, Wenhui;Nanga, Ravi Prakash Reddy;Kang, Cong Bao;Song, Joo-Hye;Song, Seong-Kyu;Yoon, Ho-Sup
    • BMB Reports
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    • v.39 no.5
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    • pp.560-570
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    • 2006
  • Mistletoe (Viscum album) lectins, which are classified as a type II ribosome-inactivating protein (RIP) due to their unique biological function and the potential medical and therapeutic application in cancer cells, receive a rising attention. The heterodimeric glycoproteins contain the A-chain with catalytic activity and the B-chain with sugar binding properties. In recent years, studies involving the lectins from the white berry European mistletoe (Viscum album) and the yellow berry Korean mistletoe (Viscum album coloratum) have been described. However, the detailed mechanism in exerting unique cytotoxic effect on cancer cells still remains unclear. Here, we aim to understand and define the molecular basis and biological effects of the type II RIPs, through the studies of the recombinant Korean mistletoe lectin. To this end, we expressed, purified the recombinant Korean mistletoe lectin (rKML), and investigated its molecular characteristics in vitro, its cytotoxicity and ability to induce apoptotic cell death in cancer cells. To gain structural basis for its catalytic activity and sugar binding properties, we performed homology modeling studies based on the high degree of sequence identity and conserved secondary structure prediction between Korean and European, Himalayan mistletoe lectins, and Ricin.

Structural Requirements of Minoxidil Analogs for Enhancing Lysyl Hydroxylase Inhibitory Activity (Lysyl Hydroxylase의 저해활성을 증가시키기 위한 Minoxidil 유도체들의 구조적인 요건)

  • Myung, Pyung-Keun;Sung, Nack-Do;Lee, Jae-Heung
    • KSBB Journal
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    • v.27 no.2
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    • pp.121-126
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    • 2012
  • In order to explore structural features of minoxidil analogs with a view of enhancing lysyl hydroxylase (LH) inhibitory activity, molecular holographic QSAR (HQSAR) and CoMSIA (comparative molecular similarity indices analysis) were performed. The results from the atomic contributions with optimized the HQSAR 6-2 model indicated that, in case of pyrimidine-1-N-oxide substituent, C2 atom of pyrimidine ring and C'3-C'4 bond of 4-piperidinol group showed the highest impact on the inhibitory activity towards LH enzyme. It was also evident from the information of the optimized CoMSIA F5 model that the inhibitory activity mainly depended on the hydrophobic field contribution (36%) and the hydrogen bond (H-bond) field contribution (49.2%) of substrate molecule. Particularly, it is predicted that the functional groups which disfavor H-bond acceptors in large space around the piperidinol group and also the functional groups which favor the H-bond acceptors at C'4 (& C'5) atom in $R_5$ group play a role for increased inhibitory activity. With this in mind, it is likely that a novel candidate having more improved inhibitory activity on hair growth could be designed in the future.

A study on the Structural Relationship among Innovation Activity, Innovation Performance, and Business Performance of Export Firms (수출기업의 혁신활동, 혁신성과, 경영성과 간의 구조적 관계에 관한 연구)

  • Yong-Hyun Cho
    • Korea Trade Review
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    • v.46 no.5
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    • pp.195-211
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    • 2021
  • The purpose of this study is to examine the relationship among innovation activities, innovation performance, and management performance of export firms. I first undertake a review of previous studies related to innovation activity, innovation performance, and export firms' innovation. Based on this, I set up a research model and hypotheses. First, The innovation activity is classified into product innovation activity, process innovation activity, and administrative innovation activity. Innovation performance is divided into product quality improvement and cost reduction. And the business performance is regarded as financial performance of export's firms. This study examined whether innovation activity affect innovation performance such as product quality improvement and cost reduction. In addition, I examined whether these innovation performance affects business performance (financial performance). To achieve this, a total of 368 questionnaires are used in this study and PLS (Partial Least Square) was used to analyze structural equation. As a result, this study shows that product innovation activity have a positive effect on product quality improvement, and process innovation activity also have a positive effect on product quality improvement. However, it was found that neither product innovation activity nor process innovation activity had an effect on cost reduction. And it was found that administrative innovation did not affect product quality improvement, but had a positive effect on cost reduction. Also, it was found that quality improvement, which is an innovation performance, did not affect the financial performance of export's firms, and cost reduction, which is an innovation performance, had a positive effect on the financial performance of the export's firms.

A Study on the Structural Relationship between SCM Activity and Process Innovation, and Quality Performance in SMEs (중소기업의 SCM활동과 프로세스 혁신 및 품질성과 간의 구조적 관계 분석)

  • Lee, Seol-Bin
    • The Journal of the Korea Contents Association
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    • v.19 no.2
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    • pp.170-185
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    • 2019
  • This study is intended to look into the structural relationship between SCM activity, process innovation and quality performance in small and medium sized enterprisers(SMEs). To achieve this, a survey was empirically carried out to 354 SCM operating officers and managers who perform the SCM activities in small and medium sized manufacturing firms. The results are summarized as follows. Overall, the SCM activity and process innovation had a significant effect on the quality performance, having a structural relationship with the quality performance in SEMs. This implies that the strategic alliance of the SCM activities and competence concentration based on technology development in SEMs can organize the unity through organizational members' information sharing. In other words, when the information integration supports the compatibility and reliability of shared information system by raising technological competence through this, the process innovation can lead to non-financial cost reduction, product quality, delivery compliance and inventory cost reduction as quality performance of the structured process, management and distribution.

Effect of Substrate on Electroless Co-Base Deposited Films (무전해 코발트계 석출막에 미치는 기판의 영향)

  • Han, Chang-Suk;Chun, Chang-Hwan;Han, Seung-Oh
    • Korean Journal of Materials Research
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    • v.19 no.6
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    • pp.319-324
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    • 2009
  • The deposition behavior and structural and magnetic properties of electroless Co-B and Co-Fe-B deposits, as well as the amorphous ribbon substrates, were investigated. These Co-based alloy deposits exhibited characteristic polycrystalline structures and surface morphology and magnetic properties that were dependent on the type of amorphous substrates. The catalytic activity sequence of the amorphous ribbon electrodes for anodic oxidation of DMAB was estimated from the current density-potential curve in the anodic partial electrolytic bath that did not contain the metal ions. Both the deposition rate and potential in the initial region were obtained in order of the catalytic activity, depending on the alloy compositions of the substrates. The deposition rate linearly varied against the deposition time. The initial deposition potential may have also determined the structural and magnetic properties of the deposit based on the thickness of ${\mu}m$ order. Furthermore, a basic study of the electroless deposition processes on an amorphous ribbon substrate has been carried out in connection with the structural and magnetic properties of the deposits.

Structural characterization and anti-inflammatory activity of fucoidan isolated from Ecklonia maxima stipe

  • Lee, Hyo-Geun;Nagahawatta, D.P.;Liyanage, N.M.;Jayawardhana, H.H.A.C.K.;Yang, Fengqi;Je, Jun-Geon;Kang, Min-Cheol;Kim Hyun-Soo;Jeon, You-Jin
    • ALGAE
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    • v.37 no.3
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    • pp.239-247
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    • 2022
  • Enzyme-assisted hydrolysis is frequently used as a cost-effective and efficient method to obtain functional ingredients from bioresources. This study involved the enzyme-assisted hydrolyzation and purification of fucoidan from Ecklonia maxima stipe and the investigation of its anti-inflammatory activity in lipopolysaccharide (LPS)-induced RAW 264.7 cells. Fucoidans of Viscozyme-assisted hydrolysate from E. maxima (EMSFs) harvested in Jeju, Korea. Structural and chemical characterizations were performed using fourier transform infrared spectroscopy, scanning electron microscope, and monosaccharide analysis. Among fucoidans, EMSF6 was rich in fucose and sulfate and had a similar structural character to commercial fucoidan. EMSF6 showed a strong inhibitory effect on nitric oxide generation in LPS-induced RAW 264.7 cells and significantly decreased the production of LPS-induced pro-inflammatory cytokines, including interleukin-6, interleukin-1β, and tumor necrosis factor α. The anti-inflammatory potential of EMSF6 was mediated through the downregulation of inducible nitric oxide synthase and cyclooxygenase-2 expression. Thus, fucoidans from E. maxima stipe are promising candidates for functional food products.