• Title/Summary/Keyword: 2D-QSAR model

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2D-QSAR Analyses on the Binding Affinity Constants of Tetrahydropyrane and Tetrahydrofurane Analogues against Bovine Odorant Binding Protein and Predicted of High Active Molecules (Bovine Ordorant Binding Protein에 대한 Tetrahydropyrane 및 Tetrahydrofurane 유도체들의 결합 친화력 상수에 관한 2D-QSAR 분석과 고활성 분자의 예측)

  • Park, Chang-Sik;Sung, Nack-Do
    • Reproductive and Developmental Biology
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    • v.33 no.3
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    • pp.119-123
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    • 2009
  • The two dimensional quantitative structure-activity relationships (2D-QSARs) models concerning the binding affinity constants ($p[Od.]_{50}$) between 2-cyclohexyltetrahydropyrane and 2-cyclohexyltetrahydrofurane analogues as substrates, and bovine odorant binding protein (bOBP) as receptor were derived by multiple regression analyses method and discussed. The statistical quality of the optimized 2D-QSAR model (5) was good (r=0.907). From the model, the binding affinity constants ($p[Od.]_{50}$) were dependent upon the optimal value ($(TL)_{opt.}$=2.737) of total lipole (TL) of substrate molecules. Based on these findings, the high active compounds predicted by optimized 2D-QSAR model (5) were 2-(dimethylcyclohexyl)tetrahydropyrane molecule and their isomer molecules. The binding affinity constants regarding bOBP of the tetrahydrofuryl-2-yl family compounds were dependent upon the hydrophobicity (logP) of whole substrate molecules. In any case of porcine odorant-binding proteins (pOBP), the constants were dependent upon the hydrophobicity (${\pi}x={\log}P_X-{\log}P_H$) of substituents (R) in substrate molecules. Also, from the optimal values of hydrophobic constant, the hydrophobicity for bOBP influenced ca. twice time bigger (bOBP>pOBP) than that for pOBP.

The Search of Pig Pheromonal Odorants for Biostimulation Control System Technologies: A 2D-QSAR Model for Binding Affinity between 2-Cyclohexyloxytetrahydrofurane Analogues and Porcine Odorant Binding Protein (생물학적 자극 통제 수단으로 활용하기 위한 돼지 페로몬성 냄새 물질의 탐색: 2-Cyclohexyloxytetrahydrofurane 유도체와 Porcine Odorant Binding Protein 사이의 결합 친화력에 관한 2D-QSAR 모델)

  • Park, Chang-Sik;Choi, Yang-Seok;Sung, Nack-Do
    • Reproductive and Developmental Biology
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    • v.31 no.1
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    • pp.15-20
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    • 2007
  • To search of a new porcine pheromonal odorant for biostimulation control system technologies to offer a potentially useful and practical way to improve reproductive efficiency in livestock species, the two dimensional quantitative structure-activity relationship (QSAR) models between physicochemical parameters as descriptors of 2-cyclohexyloxytetrahydrofurane (A), 2-phenoxytetrahydrofurane (B) analogues and binding affinity constant ($p[Od.]_{50}$) for porcine odorant-binding protein (pOBP) as receptor of pig pheromones were derived and disscused. The statistical quality of the optimized 2D-QSAR model is good ($r^{2}=0.964$) and accounts for 96.4% of the variance in the binding affinity constants. It was found that the binding affinity constants were dependent upon the optimal value, $(SL)_{opt.}=1.418$ of substituent lipole (SL) in molecules. Therefore, the SL constant was very important factor for binding affinity.

2D-QSAR Analyses on The Tyrosinase Inhibitory Activity of 2-[(2,6-Dioxocyclohexyl)methyl]-cyclohexane-1,3-dione Analogues (2-[(2,6-Dioxocyclohexyl)methyl]cyclohexane-1,3-dione 유도체의 Tyrosinase 저해활성에 관한 2D-QSAR 분석)

  • Kim, Sang-Jin;Sung, Nack-Do
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.40 no.4
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    • pp.383-390
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    • 2014
  • The following conclusion was made from the 2D-QSAR model for the tyrosinase inhibitory activity according to the variation of the substituents R1 and R2 in analogues of compound 2-[(2,6-dioxocyclohexyl)methyl]cyclohexane- 1,3-dione (1-23). The best optimized 2D-QSAR model was $Obs.pI_{50}=-0.295({\pm}0.031)TDM$ $-0.120({\pm}0.014)DMZ+0.135({\pm}0.050)DMX.R_2+6.382({\pm}0.17)$, and the correlation $r^2=0.905$) of which was greater than its predictability ($q^2=0.843$). The magnitude of the effect of tyrosinase inhibitory activities was in order of TDM > $DMX.R_2{\geq}DMZ$, and it tended to increase as the hydrophobicity of substrate molecule (ClogP > 0) as well as the steric favor of substituent $R_1$ increased. The analysis of the model implies that inhibitory activity of substrate molecule will increase as $DMX.R_2$ (Dipole moment X component of $R_2$-substituent) increases, while TDM (Total Dipole Moment) and DMZ(Dipole Moment of Z-Component) decrease. As such, it is deemed feasible to conclude, that in order to increase the inhibitory effect, it would be rather desirable to replace the polar groups within the molecules with non-polar functional groups.

Holographic Quantitative Structure-Activity Relationship (HQSAR) Study of 3,4-Dihydroxychalcone Derivatives as 5-Lipoxygenase Inhibitors

  • Gadhe, Changdev G.
    • Journal of the Chosun Natural Science
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    • v.4 no.3
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    • pp.210-215
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    • 2011
  • Holographic quantitative structure-activity relationships (HQSAR) is a useful tool to correlates structures with their biological activities. HQSAR is a two dimensional (2D) QSAR methodology, which generates QSAR equations through 2D fingerprint and correlates it with biological activity. Here, we report a 2D-QSAR model for a series of fifty-one 3,4-dihydroxychalcones derivatives utilizing HQSAR methodology. We developed HQSAR model with 6 optimum numbers of components (ONC), which resulted in cross-validated correlation coefficient ($q^2$) of 0.855 with 0.283 standard error of estimate (SEE). The non-cross-validated correlation coefficient (r2) with 0.966 indicates the model is predictive enough for analysis. Developed HQSAR model was binned in to a hologram length of 257. Atomic contribution map revealed the importance of dihydroxy substitution on phenyl ring.

QSAR on the Inhibition Acticity of Flavopiridol Analogues against Breast Cancer MCF-7 (Flavopiridol 유도체에 의한 유방암 MCF-7 세포의 저해 활성에 관한 구조와 활성과의 관계)

  • Soung, Min-Gyu;Joo, Sung-Mo;Song, Ah-Reum;Sung, Nack-Do
    • Applied Biological Chemistry
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    • v.50 no.3
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    • pp.147-153
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    • 2007
  • To search for a molecular design of a new breast cancerous inhibitory active compound, 2D-QSAR and HQSAR between the substituents of flavopiridol analogues as substrates and their breast cancerous inhibitory activities against MCF-7 cell were analyzed and discussed quantitatively. It was found that the dispersion with molecule and steric hindrance with substituents will have a tremendous impact on the inhibitory activities from the 2D-QSAR model (1). Also, MR constant is better than that of MS constant as animportant factor. The inhibitory activities from 2D-QSAR model (2) were dependent upon the optimum MR constant (MR = 126 $Cm^3/mol$). Optimized HQSAR model (V) exhibited the best predictability of the inhibitory activities based on the cross-validated $r^2_{cv}$($q^2$= 0.583) and non-cross-validated conventional coefficient ($r^2_{ncv}$= 0.982). From the contribution maps, the inhibitory activity by the imino group on $C_9$ atom was higher than that of the hydroxyl group of $C_8$ atom on the A ring in molecule. Therefore, we can confirm that the dispersion by substituents in molecule is the most important factor in inhibitory activities against MCF-7 cell.

2D-QSAR and HQSAR Analysis on the Herbicidal Activity and Reactivity of New O,O-dialkyl-1-phenoxy-acetoxy-1-methylphosphonate Analogues (새로운 O,O-dialkyl-1-phenoxyacetoxy-1-methylphosphonate 유도체들의 반응성과 제초활성에 관한 2D-QSAR 및 HQSAR 분석)

  • Sung, Nack-Do;Jang, Seok-Chan;Hwang, Tae-Yeon
    • The Korean Journal of Pesticide Science
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    • v.11 no.2
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    • pp.72-81
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    • 2007
  • Quantitative structure-activity relationships (QSARs) on the pre-emergency herbicidal activity and reactivity of a series of new O,O-dialkyl-1-phenoxyacetoxy-1-methylphosphonates (S) analogues against seed of cucumber (Cucumus Sativa) were discussed quantitatively using 2D-QSAR and HQSAR methods. The statistical values of HQSAR model were better than that of 2D-QSAR model. From the frontier molecular orbital (FMO) interaction between substrate molecule (S) and $BH^+$ ion (I) in PDH enzyme, the electrophilic reaction was superior in reactivity. From the effect of substituents, $R_2$-groups in substrate molecule (S) contributed to electrophilic reaction with carbonyl oxygen atom while X, Y-groups contributed to nucleophilic reaction with carbonyl carbon atom. And the influence of X,Y-groups was more effective than that of $R_2$-groups. As a results of 2D-QSAR model (I & II) and atomic contribution maps with HQSAR model, the more length of X, Y-groups is longer, the more herbicidal activity tends to increased. And also, the optimal ${\epsilon}LUMO$ energy, $({\epsilon}LUMO)_{opt.}$=-0.479 (e.v.) of substrate molecule is important factor in determining the herbicidal activity. It is predicted that the herbicidal activity proceeds through a nucleophilic reaction. From the analytical results of 2D-QSAR and HQSAR model, it is suggested that the structural distinctions and descriptors that contribute to herbicidal activities will be able to applied new herbicide design.

2D-QSAR and HQSAR on the Inhibition Activity of Protein Tyrosine Phosphatase 1B with Oleanolic Acid Analogues

  • Chung, Young-Ho;Jang, Seok-Chan;Kim, Sang-Jin;Sung, Nack-Do
    • Journal of Applied Biological Chemistry
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    • v.50 no.2
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    • pp.52-57
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    • 2007
  • Quantitative structure-activity relationships (QSARs) on the inhibition activities by oleanolic acid analogues (1-19) as a potent inhibitor against protein tyrosine phosphatase-1B were studied quantitatively using 2D-QSAR and HQSAR methodologies. The inhibition activity was dependent on the variations of $R_{4-}$substituent, and as shown in 2D-QSAR model ($r^2=0.928$), it has a tendency to increase as the negative Randic Indice (RI) goes up. The size of the molecular fragments used in HQSAR varied from five to eight. The fragment distinctions had the best statistic value, whose predictability is $q^2=0.785$ and correlation coefficient is $r^2=0.970$, on condition of connections. From the atomic contribution maps, the factor that contributes to the inhibition activities is the $C_{15}{\sim}C_{17}$ bond in the D ring. From the analysis result of these two the models, the structural distinctions and descriptors that contribute to the inhibition activities were obtained.

2D-QSAR analysis for hERG ion channel inhibitors (hERG 이온채널 저해제에 대한 2D-QSAR 분석)

  • Jeon, Eul-Hye;Park, Ji-Hyeon;Jeong, Jin-Hee;Lee, Sung-Kwang
    • Analytical Science and Technology
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    • v.24 no.6
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    • pp.533-543
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    • 2011
  • The hERG (human ether-a-go-go related gene) ion channel is a main factor for cardiac repolarization, and the blockade of this channel could induce arrhythmia and sudden death. Therefore, potential hERG ion channel inhibitors are now a primary concern in the drug discovery process, and lots of efforts are focused on the minimizing the cardiotoxic side effect. In this study, $IC_{50}$ data of 202 organic compounds in HEK (human embryonic kidney) cell from literatures were used to develop predictive 2D-QSAR model. Multiple linear regression (MLR), Support Vector Machine (SVM), and artificial neural network (ANN) were utilized to predict inhibition concentration of hERG ion channel as machine learning methods. Population based-forward selection method with cross-validation procedure was combined with each learning method and used to select best subset descriptors for each learning algorithm. The best model was ANN model based on 14 descriptors ($R^2_{CV}$=0.617, RMSECV=0.762, MAECV=0.583) and the MLR model could describe the structural characteristics of inhibitors and interaction with hERG receptors. The validation of QSAR models was evaluated through the 5-fold cross-validation and Y-scrambling test.

CoMSIA Analysis on The Inhibition Activity of PTP-1B with 3${\beta}$-Hydroxy-12-oleanen-28-oic Acid Analogues (3${\beta}$-Hydroxy-12-oleanen-28-oic Acid 유도체들의 PTP-1B저해활성에 대한 CoMSIA분석)

  • Kim, Sang-Jin;Chung, Young-Ho;Kim, Se-Gon;Sung, Nack-Do
    • Applied Biological Chemistry
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    • v.51 no.3
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    • pp.171-176
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    • 2008
  • The comparative molecular similarity indices analysis (CoMSIA) models between 3${\beta}$-Hydroxy-12-oleanen-28-oic acid (1-30) analogues as substrate molecule and their inhibitory activities ($pI_{50}$) against protein tyrosine phosphatase (PTP)-1B were derived and discussed quantitatively. Listing in order, the CoMFA>CoMSIA${\geq}$HQSAR>2D-QSAR model, these QSAR models had the better statistical values. The optimized CoMSIA F1 model at grid 3.0${\AA}$ had the best predictability and fitness ($q^2$=0.754 and $r^2$=0.976) by field fit alignment. The order of contribution ratio (%) of CoMSIA fields concerning the inhibitory activities was a H-bond acceptor (48.9%), steric field (25.8%) and hydrophobic field (25.4%), respectively. Therefore, the inhibitory activities of substrate molecules against PTP-1B were dependent upon H-bond acceptor field (A) of $R_4$-group. From the analytical results of CoMSIA contour maps, oleanolic acid derivatives will have better inhibition activities if $R_1$ group has H-bond acceptor disfavor, $R_3$group has steric disfavor and $R_4$ group has steric, hydrophobic, H-bond favor.