• Title/Summary/Keyword: Indices of similarity

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CoMFA and CoMSIA 3D QSAR Studies on Pimarane Cyclooxygenase-2 (COX-2) Inhibitors

  • Lee, Kwang-Ok;Park, Hyun-Ju;Kim, Young-Ho;Seo, Seung-Yong;Lee, Yong-Sil;Moon, Sung-Hyun;Kim, Nam-Joong;Park, Nam-Song;Suh, Young-Ger
    • Archives of Pharmacal Research
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    • v.27 no.5
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    • pp.467-470
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    • 2004
  • Comparative molecular field analysis and comparative molecular similarity indices analysis were performed on twenty five analogues of pimarane COX-2 inhibitor to optimize their cyclooxygenase-2 (COX-2) selective anti-inflammatory activities.

3D-QSAR Study of Competitive Inhibitor for Acethylcholine Esterase (AChE) Nerve Agent Toxicity

  • San Juan, Amor A.;Cho, Seung-Joo
    • Molecular & Cellular Toxicology
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    • v.2 no.3
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    • pp.216-221
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    • 2006
  • The cholinesterase-inhibiting organophosphorous (OP) compounds known as nerve agents are highly toxic. The principal toxic mechanism of OP compounds is the inhibition of acethylcholine esterase (AChE) by phosphorylation of its catalytic site. The reversible competitive inhibition of AChE may prevent the subsequent OP intoxication. In this study, three-dimensional quantitative structure-activity relationship (3D-QSAR) was performed to investigate the relationship between the 29 compounds with structural diversity and their bioactivities against AChE. In particular, predictive models were constructed using the comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA). The results indicate reasonable model for CoMFA ($q^{2}=0.453,\;r^{2}=0.697$) and CoMSIA ($q^{2}=0.518,\;r^{2}=0.696$). The presence of steric and hydophobic group at naphtyl moiety of the model may lead to the design of improved competitive inhibitors for organophosphorous intoxication.

3D-QSAR of Non-peptidyl Caspase-3 Enzyme Inhibitors Using CoMFA and CoMSIA

  • Lee, Do-Young;Hyun, Kwan-Hoon;Park, Hyung-Yeon;Lee, Kyung- A.;Lee, Bon-Su;Kim, Chan-Kyung
    • Bulletin of the Korean Chemical Society
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    • v.27 no.2
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    • pp.273-276
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    • 2006
  • Three dimensional quantitative structure-activity relationship studies for a series of isatin derivatives as a nonpeptidyl caspase-3 enzyme inhibitor were investigated using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA). The first approach of non-peptidyl small molecules by 3D QSAR may be useful in guiding further development of potent caspase-3 inhibitors.

3D-QSAR Analysis and Molecular Docking of Thiosemicarbazone Analogues as a Potent Tyrosinase Inhibitor

  • Park, Joon-Ho;Sung, Nack-Do
    • Bulletin of the Korean Chemical Society
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    • v.32 no.4
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    • pp.1241-1248
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    • 2011
  • Three dimensional quantitative structure-activity relationships (3D-QSARs) between new thiosemicarbazone analogues (1-31) as a substrate molecule and their inhibitory activity against tyrosinase as a receptor were performed and discussed quantitatively using CoMFA (comparative molecular field analysis) and CoMSIA (comparative molecular similarity indices analysis) methods. According to the optimized CoMSIA 2 model obtained from the above procedure, inhibitory activities were mainly dependent upon H-bond acceptor favored field (36.5%) of substrate molecules. The optimized CoMSIA 2 model, with the sensitivity of the perturbation and the prediction, produced by a progressive scrambling analysis was not dependent on chance correlation. From molecular docking studies, it is supposed that the inhibitory activation of the substrate molecules against tyrosinase (PDB code: 1WX2) would not take place via uncompetitive inhibition forming a chelate between copper atoms in the active site of tyrosinase and thiosemicarbazone moieties of the substrate molecules, but via competitive inhibition based on H-bonding.

Molecular modeling of COX-2 inhibitors: 3D-QSAR and docking studies

  • Kim, Hye-Jung;Chae, Chong-Hak;Yoo, Sung-Eun;Yi, Kyu-Yang;Park, Kyung-Lae
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.65.2-65.2
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    • 2003
  • 88 selective COX-2 inhibitors belonging to three chemical classes (triaryl rings, diaryl cycloalkanopyrazoles, and diphenyl hydrazides) were studied using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA). Partial least squares analysis produced statistically significant models with q values of 0.84 and 0.79 for CoMFA and CoMSIA, respectively. The key spatial properties were detected by careful analysis of the isocontour maps. The binding energies calculated from flexible docking correlated with inhibitory activities by the least-squares fit method. (omitted)

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Analysis of Reference Inquiries in the Field of Social Science in the Collaborative Reference Service Using the Co-Word Technique

  • Cho, Jane
    • Journal of the Korean Society for Library and Information Science
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    • v.49 no.1
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    • pp.129-148
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    • 2015
  • This study grasped the true nature of the inquiry domain by analysing the requests for collaborative reference service in the social science field using the co-word technique, and schematized the intellectual structure. First, this study extracted 748 uncontrolled keywords from inquiries for reference in the field of social science. Second, calculated similarity indices between the words on the basis of co-occurrence frequency, and performed not only clustering but also MDS mapping. Third, to grasp the difference in inquiries for reference by period, dividing the period into two parts, and performed comparative analysis. As a result, there formed 5 clusters and "Korea Education" showed an overwhelming size with 40.3% among those clusters. The result of the analysis through the period division showed there were many questions about "Education" during the first half, while a lot of inquiries with focus on "welfare and business information" during the second half.

Size-distribution for Major Tree Species in Kwhangnung Forest Communities (광릉 임삼군집내 주요 수종의 직경계분포에 관하여)

  • 김윤동
    • Journal of Plant Biology
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    • v.20 no.4
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    • pp.141-149
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    • 1977
  • In this sampling obtained 7,108 measurements for all trees larger than 2.5cm (1.0 inch) dbh from seven stands in Kwhangnung. In terms of similarity indices seven stands are classified into three kind of forest coniferous, mixed, and broadleaved froest communiteis. For ten major tree species in a three forest communities the size distributions are studied. Two forms of size distributions were observed: (1) linear relationships of log numbers of stem vs. size indicating stablesize distributions; (2) convex to bell shaped size distributions reflecting declining populaitons with a low natality rate. Survivorship analyses showed that successional trends seem to be: Pinus densilfloralongrightarrowQuercus aliena and Q. serratalongrightarrowCarpinus laxifloralongrightarrowC. erosalongrightarrowAcer pseudo-sieboldianum var. Koreanum. These results agree with the results from ordination method. An alternate pathways that Pinus koraiensis seems to be replaced by C. laxiflora were observed. It seems that successional trend is not unidireciton, but rather multi-directional.

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Quantitative Structure Activity Relationship between Diazabicyclo-[4.2.0]octanes Derivatives and Nicotinic Acetylcholine Receptor Agonists

  • Kim, Eun-Ae;Jung, Kyoung-Chul;Sohn, Uy-Dong;Im, Chae-Uk
    • The Korean Journal of Physiology and Pharmacology
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    • v.13 no.1
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    • pp.55-59
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    • 2009
  • Three dimensional quantitative structure activity relationship between diazabicyclo[4.2.0]octanes and nicotinic acetylcholine receptor($h{\alpha}4{\beta}2$ and $h{\alpha}3{\beta}4$) agonists was studied using comparative molecular field analysis(CoMFA) and comparative molecular similarity indices analysis(CoMSIA). From 11 CoMFA and CoMSIA models, CoMSIA with steric and electrostatic fields gave the best predictive models($q^2=0.926$ and 0.945, ${r^2}_{ncv}=0.983$ and 0.988). This study can be used to develop potent $h{\alpha}4{\beta}2$ receptor agonists with low activity on $h{\alpha}3{\beta}4$ subtype.

Design of Novel JNK3 Inhibitors Based on 3D-QSAR In Silico Model

  • Madhavan, Thirumurthy
    • Journal of Integrative Natural Science
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    • v.5 no.1
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    • pp.6-12
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    • 2012
  • c-Jun N-terminal kinase-3 (JNK-3) has been identified as a promising target for neuronal apoptosis and has the effective therapeutic for neurodegenerative diseases such as Parkinson's disease, Alzheimer's disease, and other CNS disorders. Herein, we report the essential structural and chemical parameters for JNK-3 inhibitors utilizing comparative molecular field similarity indices analysis (CoMSIA) using the derivatives of 3,5-disubstituted quinolines. The best predictions were obtained CoMSIA model (q2=0.834, r2=0.987) and the statistical parameters from the generated 3D-QSAR models were indicated that the data are well fitted and have high predictive ability. The resulting contour map from 3D-QSAR models might be helpful to design novel and more potent JNK3 derivatives.

Segmentation of Scalp and Skull in brain MR Images Using CannyEdge Level Set Method

  • Du, Ruoyu;Lee, Hyo Jong
    • Proceedings of the Korea Information Processing Society Conference
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    • 2010.11a
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    • pp.668-671
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    • 2010
  • In this paper, we present a novel automatic algorithm for scalp and skull segmentation in T1-weighted head MR images. First, the scalp and skull part are constructed by using intensity threshold. Second, the scalp outer surface is extracted based on an active level set method. Third, the skull inner surface is extracted using a canny edge detection algorithm. Finally, the fast sweeping, tagging and level set methods are applied to reconstruct surfaces from the detected points in three-dimensional space. The results of the new segmentation algorithm on MRI data acquired from eight persons were compared with manual segmented data. The average similarity indices for the scalp and skull segmented regions were equal to 84.42% for the test data.