• 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.

• Applied Biological Chemistry
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• v.51 no.2
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• pp.119-123
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• 2008

3D-QSARs (3 dimensional quantitative structrue-activity relationships) on the inhibition activities of 3-substituted-5,5'-diphenylimidazolidine-2,4-dione derivatives (1-22) against FAAH (fatty acid amide hydrolase) were studied quantitatively using CoMFA (comparative molecular field analysis) and CoMSIA (comparative molecular similarity indice analysis) methods. The statistical results of the CoMFA 1A and CoMSIA 2F model are better predictability and fitness. And also, the designed X=I, Y=$N_{2}^{+}$-substituent (P1: $Pred.pI_{50}$=6.55), according to the contour maps with information of the two models, showed the most inhibition activity against FAAH.

• Applied Biological Chemistry
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• v.50 no.3
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• pp.187-191
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• 2007

Comparative molecular similarity indice analysis (CoMSIA) models on the fungicidal activities of N-phenyl substituents (X) in N-phenyl-O-phenylthionocarbamate derivatives against rice sheath blight (Rhizoctonia solani: RS) and phytophthora blight (Phytophthora capsici: PC) were derived. Also, the characterizations of H-bonds between substrates and ${\beta}-tubulin$ were discussed quantitatively. It was revealed that, from the contour maps of CoMSIA models, the H-bond acceptor field contributed the most highly to fungicidal activity for two fungi in common. It is predicted that the selectivity in the fungicidal activity between two fungi is caused by results from the roles of H-bond donor disfavor functional groups in RS and H-bond acceptor disfavor functional groups in PC when these two groups induced at meta- and para-position on the N-phenyl ring. And also, if the substituents (X) are steric disfavor group, negative charge favor groups are introduced at the metaposition in RS and H-bond acceptor group is introduced at the para-position in PC, the antifungal activity against two fungi will be likely able to be increased.

• The Korean Journal of Pesticide Science
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• v.14 no.1
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• pp.72-77
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• 2010

The minimum structural requirements of R-phenoxy substituents for herbicidal evaluation of O-(2-(R)-phenoxy)-ethyl-N-aralkylcarbamate (1-15) analogues against phytoene desaturase (PDS) based on the three dimensional quantitative structure-activity relationships (3D-QSARs: CoMFA and CoMSIA) were studied quantitatively. The correlativity and predictability ($r^2_{cv.}=0.753$ and $r^2_{ncv.}=0.964$) of the CoMFA 1 model were higher than those of the rest models. The PDS inhibitory activities from the optimized CoMFA 1 model were depend upon the steric field (44.0%), electrostatic field (36.3%), and hydrophobic field (19.6%) of O-(2-(R)-phenoxy)ethyl-Naralkylcarbamate analogues. From the CoMFA contour maps on the structure of the most active compound (5), if it has the steric favor at meta-, para-position on the phenoxy ring, the negative charge favor in meta-position and positive charge favor in the outside part of para-position, the inhibitory activity will be predicted to increase. Also, if ortho-, para-position, and outside of phenoxy ring are hydrophilic favor, and meta-position is hydrophobic favor, it is predicted that the inhibitory activity against PDS will be able to increase.

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

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