• The Korean Journal of Pesticide Science
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• v.11 no.2
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• pp.59-66
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• 2007

Three dimensional quantitative structure-activity relationships (3D-QSARs) on the fungicidal activity of N-phenyl-O-phenylthionocarbamate analogues against resistant and sensitive gray mold (Botrytis cinerea) (RBC & SBC) were studied quantitatively using CoMFA and CoMSIA methods. The correlation coefficient and predict- ability of optimized CoMFA model with the atom based fit alignment were better ($r^2$ & $q^2=CoMFA{\gg}CoMSIA$) than that of CoMSIA model. And statistical values of the models on the fungicidal activity against SBC were showed higher ($r^2=SBC{\gg}RBC$) than that of RBC. In CoMFA models, steric field on the activity was more influenced than electrostatic field. And in case of CoMSIA models, the influence of CoMSIA field on the activity against RBC and SBC was differ from each other but the influence of H-bond donor field was same to the two fungi. It is revealed that the selectivity factor with CoMFA model on the fungicidal activity between the two fungi was caused on the difference of steric field. Therefore, it is predicted that the large steric field with meta- and para-substituents on the N-phenyl ring will be improved to the fungicidal activity with SBC.

• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2749-2753
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• 2009

Structural characteristics that influence on the insecticidal activity ($pI_{50}$) of 2-(n-octyl)isothiourea analogues (1-45) against the diamondback moth (Plutella xylostella, L.) based on three dimensional quantitative structure activity relationships (3D-QSARs) were discussed quantitatively using a comparative molecular field analysis (CoMFA) and a comparative molecular similarity indeces analysis (CoMSIA) methods. The statistical values of the CoMFA 2 model were better than those of the CoMSIA 1 model. The CoMFA 2 model was the optimized model with the correlativity (the training set: Ave. = 0.104 & PRESS = 0.613) and the predictability (the test set: Ave. = 0.086 & PRESS = 0.096). Insecticidal activities with the optimized CoMFA 2 model were dependent upon steric factors (79.4%) of $R_1-R_3$ substituents. From the analytical results of CoMFA contour maps, it is predicted that the R1 substituent of 1-45 which has a steric favor in a broad space, $R_2\;and\;R_3$ groups with a steric favor in a narrow space and a H-bond donor favor would have better the insecticidal activity.

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

• The Korean Journal of Pesticide Science
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• v.12 no.1
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• pp.18-23
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• 2008

3D-QSAR on the inhibitory activities of 6-bromobenzo-[4,5]imidazo[$1,2{\alpha}$]-pyridin-8,9-diones analogues as substrate molecule were studied quantitatively using CoMFA and CoMSIA methods. The statistical values of CoMFA model was better predictability and fitness than CoMSIA model. The inhibitory activities according to the optimized CoMFA 2 model were dependent on the steric field (90.4%). From the CoMFA contour maps, it is found that the branched side chain as R-group will be directly attached to the carbon atom (ipso carbon) of substituent, the inhibitory activities had expected to increase. The positive charge favor groups were placed in the position between imidazol ring and pyridine ring, the inhibitory activities would increase. And if the groups of liner type will be substituted, hydrophilic favor group would raise inhibitory activities.

• Applied Biological Chemistry
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• v.50 no.3
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• pp.192-197
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• 2007

3D-QSARs on the fungicidal activity of N-phenylbenzenesulfonamide and N-phenyl-2-thienylsulfonamide analogues (1-37) against Phytophthora blight (Phytophthora capsici) were studied quantitatively using CoMFA and CoMSIA methods. The statistical results of the optimized CoMFA (2) model ($r^2_{cv.}(q^2)$ = 0.692 & $r^2_{ncv.}$= 0.965) show better predictability and fitness than CoMSIA (2) model ($r^2_{cv.}(q^2)$ = 0.796 & $r^2_{ncv.}$= 0.958). The fungicidal activities according to the information of the optimized CoMFA (2) model were dependent upon the steric and electrostatic fields of the molecules. Therefore, from the contribution contour maps of CoMFA (2) model, it is expected that 63% contribution was caused by the steric bulk of meta-substituent ($R_1$) on the S-phenyl ring. Also, the other contribution level of 32.9% was represented by the positive charged $R_4-group$ ($R_1$) on the N-phenyl ring and para-substituent ($R_1$) on the S-phenyl ring. A series of higher active compounds, $R_1$= 3-decyl substituent ($pred.pI_50$= 5.88) etc. were predicted based on the findings.

• Bulletin of the Korean Chemical Society
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• v.31 no.5
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• pp.1355-1360
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• 2010

In order to search new inhibitors against farnesyl protein transferase (FPTase), a series of 2,3-bis-benzylidenesuccinaldehyde derivatives (1-29) were synthesized and their inhibition activities ($pI_{50}$) against FPTase were measured. From based on the reported results that the inhibitory activities of dimers 2,3-bis-benzylidenesuccinaldehydes were higher than those of monomers cinnamaldehydes, 3D-QSARs on FPTase inhibitory activities of the dimers (1-29) were studied quantitatively using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) methods. The statistical qualities of the optimized CoMFA model II ($r^2{_{cv.}}$= 0.693 and $r^2{_{ncv.}}$= 0.974) was higher than those of the CoMSIA model II ($r^2{_{cv.}}$ = 0.484 and $r^2{_{ncv.}}$ = 0.928). The dependence of CoMFA models on chance correlations was evaluated with progressive scrambling analyses. And the inhibitory activity exhibited a strong correlation with steric factors of the substrate molecules. Therefore, from the results of graphical analyses on the contour maps and of predicted higher inhibitory active compounds, it is suggested that the structural distinctions and descriptors that contribute to inhibitory activities ($pI_{50}$) against FPTase will be able to applied new inhibitor design.

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