• Reproductive and Developmental Biology
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• v.28 no.1
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• pp.45-52
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• 2004

To search a new porcine pheromonal odorants, this research for biostimulation and role of pheromone was augmented by means of "control system technologies" to offer a potentially useful and practical way to improve reproductive efficiency in livestock species. Therefore the 13 physicochemical parameters such as similarity indice (S), hydrophobicity (logP) and van der Waals molecule volume (MV) etc. of 54 steroid analogues, which are analogous of substrate molecules, 5$\alpha$-androst-16-en-3-one (P1) and 5$\alpha$-androst-16-en-3-ol (P2) of lipocalin as receptor of pig pheromones were calculated and discussed. The physicochemical properties of these steroid analogues were mainly followed by steric dissimilar of A and D ring in steroid nucleus. And we found that from correlation with S values and MV constants of molecules, the more MV constants are small, the more S values tend to approach 1. Based on this results, the S-values of 4-androsten-3,17-dione (P1-1) and 5 $\alpha$ -androstan-3-one (P2-1) were 1.0, respectively. The two compounds of them were chosen because they showed the same value each other at a side of hydrophobicity, molar refractivity and molecular volume. It is expected that the new two compounds will be able to substitute for P1 and P2, porcine pheromonal odorants.

• Applied Biological Chemistry
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• v.51 no.3
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• pp.219-222
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• 2008

In the search for third generation herbicidal cyclic imide derivatives, the average values of herbicidal activity ($pI_{50}$) in vivo (pre-emergence) of 40 new peroxidizing herbicides, 1-(4-chloro-2-fluoro-5-propargyloxyphenyl)thiourea derivatives (1-40) against rice plant (Orysa sativa) and barnyard grass (Echinochlor crus-galli) were studied. The molecular similarity between protoporphyrinogen IX (protogen) as the substrate of protox enzyme and Urea derivatives (1-40) was discussed quantitatively. The diallyl (20) and 3-nitro substituent (33) showed the selective herbicidal activity against barnyard grass. Allyl substituent (8) and their molecular similarity in dice (S=0.81) showed the highest levels of herbicidal activity ($pI_{50}$=4.71). Also, similarity indices (S) and superimposed volume (C) of protogen and aryl-substituents (21-40) showed good correlation.

• 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.

• 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.

• Journal of Applied Biological Chemistry
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• v.53 no.2
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• pp.99-104
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• 2010

The influences on antioxidant activities of the substituents ($R_1-R_4$) on benzo ring in 4-Methyl-2H-benzopyran-2-one analogues (1-23) were discussed quantitatively using three dimensional quantitative structure-activity relationships (3D-QSARs: Comparative molecular field analyses (CoMFA) and Comparative molecular similarity indice analyses (CoMSIA)) methods. The statistical qualities of CoMSIA models were better than those of CoMFA models and the CoMSIA 2 model was optimized model ($q^2$=0.700 & $r^2$=0.979). Also, the contribution ratios (%) of the optimized CoMSIA 2 model were H-bond donor field 43.5%, electrostatic field 41.8% and steric field 14.7% so that the antioxidant activity exhibited a strong correlation with H-bond donor and electrostatic factor of molecules. From the analytical results of the CoMSIA contour maps, if the positive charge favor group and H-bond donor disfavor group were placed in the $R_1-R_4$ positions on the benzo ring, it was predicted that the groups would raised the antioxidant activity.