• The Korean Journal of Pesticide Science
• /
• v.14 no.4
• /
• pp.319-325
• /
• 2010

To understand the influences of the substituents ($R_1{\sim}R_4$) on insecticidal activity of N'-phenyl-N-methylformamidine analogues (1~22) against two spotted spider mite (Tetranychus urticae), comparative molecular field analysis (CoMFA) model and comparative molecular similarity indices analysis (CoMSIA) model as three dimensional quantitative structure-activity relationships (3D-QSARs) model were derived and discussed quantitatively. From the results, the correlativity and predictability ($r^2{_{cv.}}=0.575$ and $r^2{_{ncv.}}=0.945$) of the CoMFA 1 model were higher than those of the rest models. The the CoMFA 1 and CoMSIA 1 model with the sensitivity of the perturbation and the prediction produced ($d_q{^{2'}}/dr^2{_{yy}}=1.071{\sim}1.146$ & $q^2=0.545{\sim}0.626$) by a progressive scrambling analysis were not dependent on chance correlation. The insecticidal activities from the optimized CoMFA 1 model were depend upon the steric field (62.5%), electrostatic field (28.9%), and hydrophobic field (8.6%) of N'-phenyl-N-methylformamidine analogues. Therefore, the inhibitory activities with optimized CoMFA 1 model were dependent upon steric factor. From the contour maps of the optimized models, it is predicted that the structural distinctions that contribute to the insecticidal activity will be able to applied new potent insecticides design.

• Applied Biological Chemistry
• /
• v.51 no.3
• /
• pp.171-176
• /
• 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.

• The Korean Journal of Pesticide Science
• /
• v.12 no.2
• /
• pp.111-117
• /
• 2008

The comparative molecular field analysis (CoMFA) for the fungicidal activity with N-phenylbenzenesulfonamide analogues (1-45) against gray mold (Botriyts cinerea) were studied quantitatively. The statistical values of CoMFA models had much better predictability and fitness than those of comparative molecular similarity indices analysis (CoMSIA) models. The statistical values of the optimized CoMFA I model were predictablity, $r^2_{cv.}(or\;q^2)=0.457$ and correlation coefficient, $r^2_{ncv.}=0.959$, and their fungicidal activity was dependent on the steric field (52%) and electrostatic field (35.6%) of the substrate molecules. And also, it was found that the optimized CoMFA I model with the sensitivity to perturbation ($d_q^{2'}/dr^2_{yy'}=0.898$) and prediction ($q^2=0.346$ & SDEP=0.614) produced by a progressive scrambling analysis was not dependent on chance correlation. From the results of graphical analyses on the contour maps with the optimized CoMFA I model, it is expected that the $R_3$ and $R_4$-substituents on the N-phenyl ring as steric favor group and para-substituents ($R_1$) on the S-phenyl ring as steric disfavor group will contribute to the fungicidal activity. Therefore, the optimized CoMFA I model should be applicable to the prediction of the fungicidal activities against gray mold.

• YAKHAK HOEJI
• /
• v.54 no.4
• /
• pp.288-294
• /
• 2010

Three dimensional quantitative-structure relationships (3D-QSARs) models between structures of phenoxy, phenylthio or benzyloxy substituted quinolone analogues and their antitrypanosomal activity against Chagas disease (Trypanosoma cruzi) were derived and discussed quantitatively using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) methods. The optimized CoMFA 1 model ($q^2$=0.528 and $r^2$=0.964) showed the best statistical results. According to the optimized CoMFA 1 model, the antitrypanosomal activities were dependent on the steric (60.0%) and electrostatic (36.2%) factors of quinolone derivatives. From the contour maps, it is predicted that the activity will be increased when sterically favored groups were located in $R_4$ and $R_5$ position and sterically disfavored groups were located in $R_2$ position. Also, the positively charged groups on $R_2$ would be able to increase the antitrypanosomal activities.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.39 no.4
• /
• pp.329-335
• /
• 2013

Three-dimensional quantitative structure-activity relationships (3D-QSARs) models between the substituents with changing groups ($R_1$ & $R_2$) of 4-hydroxybenzyl alcohol (4-HBA) derivatives as substrate molecule and their inhibitory activities against tyrosinase were derived and discussed quantitatively. The optimized CoMSIA FF model showed the best predictability and fitness ($r^2$ = 0.858 & $q^2$ = 0.951). The contour maps of the optimized CoMSIA FF model showed that, the inhibitory activities of the analogues against tyrosinase were expected to increase when hydrophobic (Hy) favor, negative charge (E) favor, steric (S) disfavor and hydrogen bond donor (HD) disfavor groups were substituted at the $R_2$ position. When the hydrogen bond donor (HD) favor groups were substituted at the $R_1$ position, it is predicted that the substituents will be able to increase the inhibitory activity.

• Reproductive and Developmental Biology
• /
• v.32 no.3
• /
• pp.141-146
• /
• 2008

To search a new porcine pheromonal odorant, the models of four type (2D-QSAR, HQSAR, CoMFA & CoMSlA) were derived from quantitative structure-activity relationship (QSAR) between tetrahydrofuran-2-yl family compounds and their observed binding affinity constants (Obs.p$[Od]_{50}$). The optimized CoMFA model (predictability; $r^{2}_{cv.}(q^2)$=0.886 & correlation coefficient: $r^{2}_{ncv.}$=0.984) from ligand based approaches was confirmed as the best model among them. The $N^{1}$-allyl-$N^{2}$-(tetrahydrofuran-2-yl)methyl)oxalamide (P1), 2-(4-trimethylammoniummethylcyclohexyloxy)tetrahydrofurane (P5) and 2-(3-trimethylammoniummethylcyclohexyloxy)tetrahydrofurane (P6) molecules predicted as porcine pheromonal odorant by the CoMFA model were showed relatively high binding affinity constant values (Pred.p$[Od]_{50}=8{\sim}10$) and very lower toxicity values against some sorts of toxicity.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.35 no.4
• /
• pp.271-276
• /
• 2009

The 3-dimensional quantitative structure-activity relationships (3D-QSARs) models between the substituents with changing groups ($R_1$ & $R_2$) of 4-($R_1$)-benzyl alcohol and 4-($R_2$)-phenol derivatives as substrate molecule and their inhibitory activities against tyrosinase were derived and discussed quantitatively. The optimized CoMSIA 2 model have best predictability and fitness ($r^2\;=\;0.858$ & $q^2\;=\;0.951$). The contour maps of optimized CoMSIA 2 model showed that, the inhibitory activities of the analogues against tyrosinase were expected to increase when hydrophobic favor, negative charge favor, steric disfavor and hydrogen bond donor disfavor groups were substituted at the $R^2$ position. When the positive charge and the hydrogen bond donor favor groups were substituted at the $R_1$ position, it is predicted that the substituents will be able to increase the inhibitory activity. However, hydrogen bond acceptor did not affect inhibitory activities of tyrosinase.

• Reproductive and Developmental Biology
• /
• v.34 no.1
• /
• pp.7-13
• /
• 2010

The binding affinity constants ($p(Od)_{50}$) and molecular docking scores (OS) between porcine odorant binding proteins pOBP (1HQP) and pPBP (1GM6) as receptor and a series of tetrahydrofuran-2-yl (A & B) analogues as substrate, and their interactions were discussed quantitatively using three-dimensional quantitative structure-activity relationship (30-QSAR) models. The statistical qualities of the optimized CoMF A models for pOBP were better than those of the CoMSIA models. The binding affinity constants and OS between substrate and receptor molecules were dependent upon steric and hydrophobic interaction. The DS constants of the substrates into the binding site of OBP (1HQP) were bigger than those of PBP (1GM6). The resulting contour maps produced by the optimized CoMFA model were used to identify the structural features relevant to the binding affinity in binding site of pOBP.