• The Korean Journal of Pesticide Science
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• v.5 no.4
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• pp.20-26
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• 2001

A series of new 2-benzoyl-3-phenyl-2,5-dihydroisoxazol-5-one, (A) and 3-phenyl-5-phenylcarbonyl-oxyisoxazole, (B) derivatives as substrates were synthesized and their quantitative structure-activity relationships (QSAR) analyses between the antifungal activities ($pI_{50}$) and physicochemical parameters of substituents onl the benzoyl group against resistant (RPC:95CC7303) and sensitive (SPC:95CC7105) Phytophthora blight (Phytophthora capsici,) were studied. The synthetic yield (%) and antifungal activities of (A) were higher than (B) and selectivities between the fungi were not showed. From the basis on the Hansch-Fujita analyses, the optimum width values ($(B_2)_{opt.}=ca.\;4.00{\AA}$) of the substituents on the benzoyl group were important factor in determining fungicidal activity against the two fungi. Influence of the substituents as electron withdrawing group on the fungicidal activity against RPC, but not for SPC. And tile bromo- and acetyl-substituents were contributed to higher antifungal activity against RPC and SPC from the results of Free-Wilson analyses.

• Journal of Korean Traditional Oncology
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• v.11 no.1
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• pp.95-103
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• 2006

Objective: Gami-Samhwang-San, a herbal prescription for obesity treatment, is composed of seven crude herbs such as Ephedrae Herba, Scutellariae Radix, Acori Gramineri Rhizoma, Polygalae Radix, Typhae Pollen, Armeniacae Semen, Nelumbo Folium. This study was aimed to evaluate marker substances in n-butanol fraction (SH-21-B) from Gami-Samhwang-San by high performance liquid chromatography (HPLC). And we predicted inhibition activity of major compounds of Gami-Samhwang-San using Quantitative Structure Activity Relationships (QSAR) Methods: The separation was performed on a YMC J,sphere-H80 CI8(250${\times}$4.6 mm I.D) column by gradient elution with $H_3PO_4$ buffers in acetonitrile as the moblie phase at a flow-rate of 1.0ml/min. Results: HPLC was employed to determine the quantities and the qualities of several marker substances such as ephedrine, pseudoephedirne, baicalin, ${\beta}-asarone$, tenuifoliside, naringenin, amygdalin and hyperoside in the SH-21-B. Conclusion: We suggest this results could be a useful evidence for quality control of SH-21-B.

• The Korea Journal of Herbology
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• v.21 no.4
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• pp.115-121
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• 2006

Objectives : For the purpose of developing new anti-HIV agents from natural sources, the extracts of Actinidia arguta were tested for their inhibitory effects on essential enzymes as the reverse transcriptase (RT), protease and ${\alpha}-\;glucosidase$. And we predicted inhibition activity of major compounds of Actinidia arguta using Quantitative Structure Activity Relationships (QSAR). Methods : In this assay the activity of HIV-1 reverse transcriptase is measured as the formation of a strand of copy-DNA (cDNA) using RNA as a template. The activity of HIV-1 protease is measured as the cleavage of an oligopeptide by HIV-1 protease. Results : In the anti-HIV-1 RT using Enzyme Linked Oligonucleotide Sorbent Assay (ELOSA) method, water extracts (100ug/ml) of stem and leaf showed strong activity of 93.9% and 91.9%, respectively. In the HIV-1 protease inhibition assay, aqueous stem extract inhibited the activity of the enzyme to cleave an oligopeptide, resembling one of the cleavage sites in the viral polyprotein which can only be processed by HIV-1 protease with 56.8%. In the ${\alpha}-glucosidase$ inhibition assay, aqueous stem extract showed activity of 73.1%. Conclusion : We found out this result, for these samples it is possible that the inhibition of the viral replication in vitro is due to the inhibition at least one of RT and ${\alpha}-glucosidase$. It would be of great interest to identify the compounds which are responsible for this inhibition, since all therapeutically useful agent up to date are RT, PR and ${\alpha}-glucosidase$ inhibitors.

• Analytical Science and Technology
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• v.6 no.1
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• pp.1-8
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• 1993

The purpose of this study is to investigate the elution behavior of monosubstituted phenols and benzenes in micellar liquid chromatographic system, $C_{18}$ column-anionic surfactant, sodium dodecyl sulfate(SDS). The partition coefficients between the micellar pseudophase-water and modified stationary phase-water are calculated by the relationship between solute retention and micellar mobile phase(SDS) composition. The free energy of transfer of solute from water to micelle is also calculated from these values. There is a direct correlation between the hydrophobicity parameters in MLC and corresponding partition data for 1-octanol-water, which indicates that the hydrophobicity of molecules plays an important role in the partition for both systems and that quantitative structure activity relationships(QSAR) are available from studies on micellar partition. The other purpose of this study is to investigate methylene selectivity of alkyl homologous series through correlation between retention and the number of carbons. The correlation between hydrophobicity parameters in MLC and 1-octanol-water partition data was also observed when n-propanol was as a modifier in the mobile phase.

• Applied Biological Chemistry
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• v.36 no.5
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• pp.381-386
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• 1993

New twenty five Imazethapyr derivatives, [2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin -2-yl)-3-(N-methyl-N-X(sub.)-phenylaminooxoacetyl)-5-methylpyridine] were synthesized. and The quantitative structure activity relationships (QSARs) between their post-emergence herbicidal activity$(pI_{50})$ values in vivo against Barnyard grass (Echinochloa crus-galli) and physicochemical parameters of substituents(X) of 3-(N-methyl-N-X(sub.)-phenylaminooxoacetyl) group have been studied. From the basis on the findings, in case of post-emergence, the activities were dependent on the steric constant$(E_s<0)$ and electron donating $(\sigma<0)$ effect by subsitituents(X) of 3-(N-methyl-N-X(sub.)phenylaminooxoacetyl) group. Therefore, The most effective compound,15 (4-t-butyl group) and 20 (3,5-dimethyl group) were examined in this study. And the conditions on the compounds predicted to show higher herbicidal activity were also discussed.

• Applied Biological Chemistry
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• v.37 no.6
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• pp.516-521
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• 1994

New seventeen imazapyr derivatives, 2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)-3-(N-methyl-N-X(sub.)-phenylaminooxoacetyl)pyridine, 6 were synthesized and their pre-emergence herbicidal activity$(pI_{50})$ in vivo against Corn (Zea mays L.) and Pigweed (Amaranthus viridis L.) were studied by the pot test under paddly conditions. Quantitative structure activity relationships (QSARs) were analyzed using the physicochemical parameters of substituent(X) on the phenyl ring of 3-(N-methyl-N-X(sub.)-phenylaminooxoacetyl) group and regression analysis. The herbicidal activities were related to the steric effect of X-substituent. The effect was rationalized by paraholic function of MR and $L_1$, where the optimal values were MR=5.56 (Zea mays L.) and $L_1=3.34\;{{\AA}}$ (Amaranthus viridis L.). Among them, 2,5-difluoro substituted compound, 6i showed good herbicidal activity against Pigweed with excellent tolerance to Corn.

• Applied Biological Chemistry
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• v.33 no.3
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• pp.231-238
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• 1990

The structure-antifungal activity correlations between the structure of fourteen new 1-(phenoxymethyl)benzotriazoles (I) (Y=0), 1-(thiophenoxymethyl)benzotriazoles (ll) (Y=S) and 1-(azidomethyl)benzotriazole (III) derivatives were synthesized, and their activity, fifty percent inhibition of mycelial growth($pI_{50}$), in vitro against Pyricularia oryzae, Fusarium axysporum f.sp sesami, Valsa ceratosperma and Botrytis cinerea were investigated using a generalized QSAR method. The activity of (I) was superior In those of (II) and (III). The effect of the substituents (X) on the phenoxy group (I) was rationalized by a parabolic function of electronic (${\sigma}$), steric ($B_1$) and hydrophobic parameter(${\pi}$), and hydrogen bonding (HB). Where the optimal values of substituent on the fungicidal activity againt P. oryzae and F. axysporum f.sp.sesami are $B_1=1.40A;(H)$ and ${\pi}=0.07{\sim}0.15;(H)$, and those of substituent on the fungicidal activity against V. ceratosperma and B. cinerea are ${\sigma}=0.23{\sim}0.28;\;(C1),\;{\pi}=0.70;$ (C1), respectively. The most effective compound ( I a) and ( I d) were examined in this study.

• The Korean Journal of Pesticide Science
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• v.12 no.1
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• pp.9-17
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• 2008

QSARs (Quantitative structure-activity relationships) between a series of new cyclohexanedione derivatives (5-benzofuryl-2-[1-(alkoxyimino)-alkyl]-3-hydroxycyclohex-2-en-1-ones) and their herbicidal activity against Rice plant (Oryza sativa L.) and Barnyard grass (Echinochloa crus-galli.) were discussed quantitatively using 2D-QSAR and holographic (H) QSAR methods. Generally, the HQSAR models have better predictability and fitness than the 2D-QSAR models. The herbicidal activities against Barnyard grass with 2D-QSAR II model were dependent upon Balaban indice (BI) of molecule and hydrophobicity of $R_1$ and $R_3$ group. And also, the $R_3=ethyl$ group, according to the information of the optimized HQSAR IV model, was more contribute to the herbicidal activities against Rice plant, while the 5-(cyclohex-3-enyl)-2,3-dihydrobenzofuran ring part was not contribute to the herbicidal activities against two plants.

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

• The Korean Journal of Pesticide Science
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• v.9 no.3
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• pp.199-204
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• 2005

The herbicidal activities against barnyardgrass (Echinochloa crus-galli) by R-groups on the hexahydroisoindol-1-one ring of new 2-(4-chloro-5-(2-chloroallyloxy)-2-fluorophenyl) -3-thioalkoxy-2,3,4,5,6,7-hexahydroisoindol-1-one derivatives were studied using molecular holographic quantitative structure-activity relationships (HQSAR) methodology. Based on the results, the statistical results of the optimised HQSAR model (I-2) exhibited the best predictability and fitness for the herbicidal activities based on the cross-validated value ($r^2_{cv.}$ or $q^2=0.714$) and non-cross-validated value ($r^2_{ncv.}=0.922$), respectively. From the based graphical analyses of atomic contribution maps, herbicidal activities against barnyardgrass were confirmed depends upon the C4-C6 atoms of hexahydroisoindoline-l-one ring, carbon atom of ortho-position and meta-methyl group of 3-tolylthio substituent (8).