• Applied Biological Chemistry
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• v.43 no.1
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• pp.52-56
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• 2000

The influence of the 2-(4-(6-chloro-2-benzoxazolyloxy)phenoxy)-N-phenyl- propionamide derivatives on the herbicide activities against rice plant with pre-emergence and post-emergence in down land were examined and the structure activity relationship (SAR) were analyzed by Free-Wilson and Hansch method. In pre-emergence, the SAR approach is shown that the optimal, $({\pi})_{opt}=0.91$, hydrophobicity with electron donating effect of the ortho substituted mono substituents and 2,3,4-substituted three substituents were found to be contribute the herbicidal activity. Whereas, in post-emergence, the optimal, ({\pi})_{opt}=0.50$, hydrophobicity with electron withdrawing effect of meta substituted mono subsituents and 2,3-substituted two substituents were found to be contribute the herbicide activity. The herbicide activities with post-emergence more increase than that of pre-emergence. It is assumed from the SAR equations that the 2-methyl-3-methoxy-4-cyano group substituent is selected as the most lowest herbicide activity against rice plant with post-emergence in green house. The hydrolysis reaction was proceeded through nucleophilic addition-elimination (Ad_{Nu-E})$ with the orbital control between LUMO of substrate and HOMO of water molecule. And molecular electrostatic potential (MEP) of none (H) substituent was discussed.

• Applied Biological Chemistry
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• v.39 no.2
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• pp.140-146
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• 1996

Imidacloprid and a series of the related compounds were synthesized, and influence of 3-N substituents(R) on the insecticidal activities against Brown plant hopper(Nilaparvata lugens) and Green peach aphid(Myzus persicae) were examined quantitatively from the structure-activities relationships(Shh) techniques. The results indicated that the molecular hydrophobicity$({\pi})$ and inductive substituent constant$({\sigma}^{\ast})$ of substituents(R) at 3-nitrogen position on the imidazolidine ring were important factors. Variations in the potency were parabolically related to the both constants. In case of Brown plant hopper, optimum value of ${\pi}$ constant was 0.52, whereas the value of ${\sigma}^{\ast}$ constant against Green peach aphid was 1.17, respectively. Among them, the strong electron withdrawing groups$({\sigma}^{\ast}>0)$ such as methyl and benzenesulfonyl group(7 & 8) showed lower insecticidal activity and non-substituted, 1(imidacloprid) showed the best insecticidal activity. It seems that the intramolecular associated(H-bond) form between 2-N-nitro group and 3-imid group may contribute to the higher insecticidal activity to the both sucking insects. And in aqueous solution, 1 showed higher residual activity below pH 6.0, and the half-life$(T_{1/2})$ was about 6 month at pH 7.0 $(ca.\;k_{obs.}:5{\times}10^{-8}sec.^{-1})$ and $45^{\circ}C$.

• Applied Biological Chemistry
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• v.42 no.1
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• pp.68-72
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• 1999

The cytotoxicity of 1,3-diphenylpropenone derivatives known to inhibit the farnesyl protein transferase (FPTase) was examined against various established tumor cell line, A549 (lung cancer), SKMEL-2 (uterine cancer), HCT-15 (skin cancer), SKOV-3 (brain cancer) and XF-498 (colon cancer) of the 1,3-diphenylpropenone derivatives showing farnesyl protein transferase (FPTase) inhibition activity. And the structure-activity relationship (SAR) between structure of 1,3-diphenylpropenone derivatives as substrate and cytotoxicity was investigated by Free-Wilson analysis as well as Hansch method with tumor cell lines. From the result of Free-Wilson analyses, X-substituents on the benzoyl group have a more important role than Y-substituents on the styryl group. The 2,4-dichloro substituent, 15 and 2,4-dimethyl substituent, 16 showed the highest cytotoxicity (average pI_(50)=5.0). Particulary, the cytotoxicity of X-substituents increased with electronic effect $({\sigma})$ due to weak electron withdrawing group with optimum value $({\sigma}_{opt}=0.22{\sim}0.29})$ whereas that of Y-substituent resulted from various factors such as logP, $B_1$ and R constant.

• The Korean Journal of Pesticide Science
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• v.4 no.3
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• pp.34-39
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• 2000

A new fifteen 2,3-dihydro-2-ethyl-2,4,6,7-tetramethylbenzofuran-5-yl substituents in 5-benzofuryl-2-[1-(alkoxyimino)alkyl]-3-hydroxycyclohex-2-en-1-one derivatives as substrate were synthesized and their herbicidal activities against rice plant (Oryza sativa L.) and barnyard grass (Echinochloa crus-galli) with post emergence were measured under submerged conditions. The $R_{1}$=methyl substituents, $1{\sim}8$ showed the higher herbicidal activity to the rice plant and barnyard grass. The structure-activity relationships (SARs) on tile herbicidal activity of $R_{1}$ and $OR_{2}$ groups on the azomethine bond in substrates were analysized. From tile results of dicussed SAR, the herbicide activities against rice plant would depend largely on the steric factor, Whereas, in case of barnyard grass, the activities were governed by the hydrophobicity factor. The conditions of selective herbicide activity between the two plant species are assumed that the substrates should nave optimal hydrophobicity ( $(logP)_{opt.}=6.0$), a $R_{1}$ groups of small and a long $OR_{2}$ groups.

• The Korean Journal of Pesticide Science
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• v.4 no.3
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• pp.47-51
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• 2000

A some of synthesized 2,3-dihydro-2,2,4,6,7-pentamethylbenzofuran-5-yl substituents in 5-benzofuryl-2-[1-(alkoxyimino)alkyl]-3-hydroxycyclohex-2-en-1-one derivatives as substrates were found to show herbicidal activity against rice plant (Oryza sativa L.) and barnyard grass (Echinochloa crus-galli) with post emergence under submerged conditions. The substrate with $R_{1}$=methyl substituents, $1{\sim}5$ showed the higher herbicidal activity to the seed, 3 leaf stage of rice plant and barnyard grass. The structure activity relationships (SARs) on the herbicidal activity of $R_{1}$ and $R_{2}$ on the azomethine bond in substrate were analysized. In the condition of $R_{1}$ groups are same, the herbicidal activity against 3 leaf stage of rice plant were governed by the optimal hydrophobicity $(logP)_{opt.}=4.57$. Whereas, in the case of barnyard grass, the herbicidal activities were largely dependent upon the steric effect, $B_{2}$ constant than hydrophobicity. In order to take the selective herbicidal activity between rice plant and barnyard grass, it is assumed that the (S) should be a round shape with higher hydrophobicity (logP>4.57) than optimal value. Also, the $R_{1}$ groups must be small and the $R_{2}$ groups are advisable to be unsaturate.

• Journal of Photoscience
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• v.2 no.2
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• pp.99-101
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• 1995

A semiempirical methods(PM3-CI-UHF, MM2) for the evaluation of ground and excited state electronic structures of electron-donating substituents are applied to 4, 5', 8-trimethylpsoralen(TMP) with TMP dimer. Three types of product have been proposed; (1) pyrone< >pyrone, (2) pyrone< >furan, (3) hetero dimer resulting from the C$_4$-cycloaddition between the furan end of one TMP moiety and the pyrone end of the other, with cis-syn configuration.

• Bulletin of the Korean Chemical Society
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• v.24 no.4
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• pp.426-430
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• 2003

A range of methine dyes has been synthesized by condensation of highly electronegative active methylene compound dicyanomethylenecyclopentane derived from cyclopentanone with the formyl group of substituted benzaldehydes. The electronic absorption spectroscopic properties of the dyes were investigated. In general, substituents on the aromatic aldehyde moiety have a significant effect on the visible absorption maxima of the dyes; increasing the solvent polarity also showed a pronounced effect on the absorption maxima.

• YAKHAK HOEJI
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• v.32 no.3
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• pp.164-169
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• 1988

$^{13}C$ NMR chemical shifts for 18 ${\alpha}-susbstituted$ toluenes at high dilution in $CCl_4$ solution have been determined. Substituents are as follows: H, Me, Et, n-Pr, iso-Pr, Ph, F, Cl, Br, $NH_2$, NHMe, $NMe_2$, OH, OMe, OCOMe, $CO_2Me$, $CO_2Et$, CN. Those chemical shifts of the methylene carbon of the toluene and the ${\alpha}-carbon$ of the n-butane systems are correlated well. (r=.975, slope=.962)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.10a
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• pp.225-228
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• 1999

The formation of dioxin (term used here to refer to both polychlorinated dibenzo-p-dioxins, PCDDS, and dibenzofurans, PCBFs) in combustion processes is of concern because of the extreme toxicities of some of these compounds and because of their resistance to degradation in the environment. The number and location of chlorine substituents differentiate dioxin homologues and isomers, respectively. There are a total of 75 PCDD congeners and 135 PCDF congeners.(omitted)

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.469-472
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• 2008

New iridium complexes with 2-(3',5'-bis-trifluoromethylphenyl)-4-metoxypyridine [$(CF_3)_2ppyOMe$] were synthesized and characterized for blue phosphorescent materials. It was found that $Ir[(CF_3)_2ppyOMe]_2$(acac) gives blue emission at 471 nm with strong luminescence efficiency. We discuss the role played by electron withdrawing substituents and also how the ancillary ligand influences the emission peak.