• Title/Summary/Keyword: Electrostatic analysis

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CoMFA Analyses on the Fungicidal Activity with N-phenylbenzensulfonamide Analogues against Gray Mold (Botrytis cinerea) (잿빛곰팡이균(Botrytis cinerea)에 대한 N-phenylbenzenesulfonamide 유도체들의 살균활성에 관한 CoMFA 분석)

  • Hwang, Tae-Yeon;Kang, Kyu-Young;Sung, Nack-Do
    • 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.

3D-QSARs Analysis on the Fungicidal Activity with N-phenylbenzenesulfonamide Analogues against Fusarium wilt (Fusarium oxysporum) (N-phenylbenzenesulfonamide 유도체들에 의한 시들음병균(Fusarium oxysporum)의 살균활성에 관한 3D-QSARs 분석)

  • Soung, Min-Gyu;Hwang, Tae-Yeon;Kang, Kyu-Young;Sung, Nack-Do
    • Applied Biological Chemistry
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    • v.51 no.1
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    • pp.38-43
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    • 2008
  • 3D-QSARs on the fungicidal activity with N-phenylbenzenesulfonamide and N-phenyl-2-thienylsul-fonamide analogues (1-34) against Fusarium wilt (Fusarium oxysporum) were discussed quantitatively using CoMFA (comparative molecular field analysis) and CoMSIA (comparative molecular similarity indices analysis) methods, respectively. Generally, the CoMFA models have better predictability and fitness than the CoMSIA models. The fungicidal activities, according to the information of the optimized CoMF A 2 model $(r^2\;_{cv.}=0.523\;&\;r^2\;_{ncv.}=0.956)$, were dependent on the electrostatic field of the N-phenylbenzenesulfonamide analogues. Therefore, from the results of graphical analyses on the contour maps with the optimized CoMFA 2 model, it is expected that the characters of $R_4-substituents$ on the N-phenyl ring as steric and positive charge favor will contribute to the fungicidal activity against Fusarium wilt.

Makeup Cleansing Formulation with Lamellar Liquid Crystal Phase (라멜라 액정상 메이크업 클렌징 제형)

  • Yeo, Hye Lim;Lee, Ji Hyun;Kim, Su Ji;Noh, Minjoo;Jang, Ji Hui;Kim, Youn Joon;Yoon, Moung Seok;Yoo, Kweon Jong;Lee, Jun Bae
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.43 no.1
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    • pp.79-86
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    • 2017
  • This study is related to a lamellar liquid crystal make-up cleansing formulation with a hologram-like unique appearance between two polarizing plates. Make-up cleansing formulations with a lamellar liquid crystal phase have been extensively studied for a long time, but there have been limitations in practical commercialization because of increasing turbidity and viscosity. In this study, to solve this problem, alkyl chains of surfactants were modified to increase the fluidity of the liquid crystal phase, and electrostatic repulsion force was increased by introducing anionic surfactant. The lamellar liquid crystal make-up cleansing formulation which introduced anionic surfactants can easily inhibit crystallization through electrostatic repulsion force, thereby showing excellent stability overtime, maintaining transparent appearance and viscosity. In addition, we have newly introduced an in vitro cleansing evaluation method using fluorescent material and in vivo imaging system (IVIS) for objective and quantitative cleansing ability evaluation. The excellent cleansing ability of lamellar liquid crystal cleansing formulation has been confirmed by newly developed evaluation method. On the other hand, when lamellar liquid crystal make-up cleansing formulation was placed between orthogonally arranged two polarizing plates, a specific pattern like a hologram can be observed. This phenomenon is presumably interpreted as the interference between the visible light passing through the liquid crystal formulation and the lamellar structure. The lamellar structure of cleansing formulation was confirmed by SAXS analysis, exhibiting Bragg spacing ratio of 1 : 2. The lamellar liquid crystal make-up cleansing formulation prepared in this study would be useful for future application in make-up cleansing due to its excellent stability, cleansing ability, and unique hologram-like pattern placed between two polarizing plates.

Effect of Coagulants on the Behavior of Ultra Fine Dust in a Coal Firing Boiler (석탄 화력 보일러에서의 응집제 이용에 따른 초미세먼지 거동)

  • Ryu, Hwanwoo;Song, Byungho
    • Applied Chemistry for Engineering
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    • v.31 no.1
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    • pp.84-89
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    • 2020
  • Particulate matters of PM2.5, particularly focusing on 0.1~1 ㎛ decrease the efficiency of dust-collector due to the brownian-motion. This study is to verify the effect of coagulant on the particle size distributions of potassium and PM2.5. The activated coagulant was spayed to the coal fired fluidized bed combustion boiler by the weight ratio of 1,200 : 1 = coal : coagulant, and the size distributions of captured particles at both the cyclone (FP) and electrostatic precipitator (EP) were measured. As the result of XRP analysis, the potassium content of FP increased to 13.33% (averagely from 1.65% to 1.87%) and, in EP at 17.68% (averagely from 1.65% to 2.03%). And it was confirmed by the particle size distribution analyzer and SEM image analysis that the distribution rates of PM2.5 decreased at 89.53% on average in FP, and at 88.57% in EP. The total dust concentration (mg/㎥) confirmed by tele-monitering system (TMS) decreased during the primary test from 2.6 to 1.7~1.9 and also the secondary test from 2.9 to 1.7~1.9.

Complexation of Omeprazole with Meglumine and its Stability (오메프라졸과 메글루민의 복합체 형성과 안정성)

  • Lee, Gye-Ju;Kim, Sung-Wook;Do, Ki-Chan;Park, Chong-Bum;Hwang, Sung-Joo
    • Journal of Pharmaceutical Investigation
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    • v.27 no.4
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    • pp.253-263
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    • 1997
  • To investigate the interaction of omeprazole (OMP) and meglumine (MEG), a complex was prepared by freeze-drying method in ammoniacal aqueous medium at room temperature and subjected to IR, DSC, and 1H NMR analysis. In addition, the stability of the complex was tested by accelerated stability analysis, and the dissolution rate of both powder and enteric coated was determined pellet by paddle method. The results are as follows; i) IR, DSC, and $^{1}H$ NMR studies indicate the formation of inclusion complex between OMP and MEG probably by electrostatic forces as $[OMP]\;[MEGH]^+$ form in a stoichiometric ratio (1:1) of OMP : MEG. ii) The dissolution rate of enteric coated OMP-MEG complex pellet in simulated enteric fluid was 90.6% in 10 minutes, which may satisfy the requirement for the regulation of dissolution. iii) OMP-MEG complex were decomposed according to pseudo 1st order kinetics: while the decomposition of OMP showed a rate constant $(k_{25^{\circ}C})$ of $5.13{\times}10^{-4}{\cdot}\;day^{-1}$, a half-life$(t_{1/2})$ of 1,350 days, a shelf-life$(T_{90%})$ 205 days and an activation energy of 23.53 kcal/mole. OMP-MEG complex inhibited a rate $(k_{25})$ of $2.92{\times}10^{-4}{\cdot}\;day^{-1}$, a half-life$(t_{1/2})$ of 2,373 days, a shelf-life $(T_{90%})$ of 306 days and an activation energy of 20.18 kcal/mole. iv) OMP was stabilized markedly by the formation of OMP-MEG complex between OMP and MEG, and the humidity increased the stability of OMP-MEG complex by decreasing the decomposition rate$(k_{50^{\circ}C})$ from $1.27{\times}10^{-2}{\cdot}\;day^{-1}$ at 31% R.H. to $2.54{\times}10^{-2}{\cdot}\;day^{-1}$ at 90% R.H.

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The Search of Pig Pheromonal Odorants for Biostimulation Control System Technologies: III. Comparative Molecular Field Analysis (CoMFA) on Binding Affinities between Ligands of 2-(Cyclohexyloxy) Tetrahydrofurane Derivatives and Porcine Odorant Binding Protein (생물학적 자극 통제 수단으로 활용하기 위한 돼지 페로몬성 냄새 물질의 탐색: III. 2-(Cyclohexyloxy) Tetrahydrofurane 유도체와 Porcine Odorant Binding Protein 사이의 결합 친화력에 관한 비교 분자장 분석)

  • Sung Nack-Do;Park Chang-Sik;Jung Hoon-Sung;Seong Min-Kyu
    • Reproductive and Developmental Biology
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    • v.30 no.1
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    • pp.13-19
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    • 2006
  • To search of new porcine pheromonal odorants for biostimulation control system technologies to improve reproductive efficiency in livestock species, the comparative molecular field analysis (CoMFA) for binding affinity constant $(p(Od)_{50})$ between porcine odorant binding protein (pOBP) and ligands of odorant 2-(cyclohexyloxy) tetrahydrofurane derivatives as substrate molecule was conducted and discussed. In the optimized CoMFA model AIV with chirality $(C_1'(R),\;C_2(S))$ in substrate molecule and atom based fit alignment (A) of odorants, the statistical results showed the best predictability of the binding affinities $(p(Od)_{50})$ based on the LOO cross-validated value $r^2_{cv}.\;(q^2=0.886)$ and non-cross-validated conventional coefficient $(r^2_{ncv}.=0.984)$. the binding affinity constants exhibited a good correlation with steric (40.8%), electrostatic (14.6%) and hydrophobic (44.6%) factors of the substrate molecules. from the analytical results of the contour maps, which may give us some valuable informations to the modification of odorants for effective binding affinity.

3D-QSAR Analysis on the Insecticidal Activities of N-Substituents on Imidazol Ring in Imidacloprid Analogues (Imidacloprid 유도체 중 imidazol 고리상 N-치환체들의 살충활성에 대한 3D-QSAR 분석)

  • Soung, Min-Gyu;Kim, Se-Gon;Soog, Nack-Do
    • The Korean Journal of Pesticide Science
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    • v.11 no.3
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    • pp.131-137
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    • 2007
  • CoMFA and CoMSIA model were derived and reviewed on the insecticidal activities of N-substituents (X) on the imidazol ring in imidacloprid analogues at the different alignment condition. Regarding the predictability ($q^2$ or $r_{cv.}^2$) and fitness ($r_{ncv.}^2$) of the two optimized models, the atom based fit (A) alignments were better than that of the field fit (F) alignment and, on the other hand, CoMSIA (A10) model was better than CoMFA (A5) model. Also, from the most optimized CoMSIA (A10) model, the insecticidal activity by N-substituents (X) was dependence on the electrostatic field and H-bond acceptor field. It is predicted that, from the contour maps with optimized CoMSIA (A10) model, H-bond acceptors at ortho- and meta- position will contribute for improving of insecticidal activities and, as the functional groups of carbonyl oxygen atom are charged negatively and positively charged at the ortho- position of benzyl group, insecticidal activities will also be improved.

3D-QSAR Analysis on the Fungicidal Activity with N-Phenylbenzenesulfonamide Analogues against Phytophthora blight (Phytophthora capsici) and Prediction of Higher Active Compounds (고추역병균(Phytophthora capsici)에 대한 N-Phenylbenzenesulfonamide 유도체들의 살균활성에 관한 3D-QSAR 분석과 고활성 화합물의 예측)

  • Soung, Min-Gyu;Kang, Kyu-Young;Cho, Yun-Gi;Sung, Nack-Do
    • 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.

Dispersion Property of Al2O3 Nanosol Prepared by Various Dispersion Factors and Silane Modification under Non-Aqueous Solvent (비수계 용매하에서 다양한 분산인자 및 실란 표면개질에 의해 제조된 Al2O3 나노졸의 분산 특성)

  • Na, Ho Seong;Park, Min-Gyeong;Lim, Hyung Mi;Kim, Dae Sung
    • Korean Journal of Materials Research
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    • v.26 no.12
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    • pp.733-740
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    • 2016
  • $Al_2O_3$ nanosol dispersed under ethanol or N-Methyl-2-pyrrolidone(NMP) was studied and optimized with various dispersion factors and by utilizing the silane modification method. The two kinds of $Al_2O_3$ powders used were prepared by thermal decomposition method from aluminum ammonium sulfate$(AlNH_4(SO_4)_2)$ while controlling the calcination temperature. $Al_2O_3$ sol was prepared under ethanol solvent by using a batch-type bead mill. The dispersion properties of the $Al_2O_3$ sol have a close relationship to the dispersion factors such as the pH, the amount of acid additive(nitric acid, acetic acid), the milling time, and the size and combination of zirconia beads. Especially, $Al_2O_3$ sol added 4 wt% acetic acid was found to maintain the dispersion stability while its solid concentration increased to 15 wt%, this stability maintenance was the result of the electrostatic and steric repulsion of acetic acid molecules adsorbed on the surface of the $Al_2O_3$ particles. In order to observe the dispersion property of $Al_2O_3$ sol under NMP solvent, $Al_2O_3$ sol dispersed under ethanol solvent was modified and solvent-exchanged with N-Phenyl-(3-aminopropyl)trimethoxy silane(APTMS) through a binary solvent system. Characterization of the $Al_2O_3$ powder and the nanosol was observed by XRD, SEM, ICP, FT-IR, TGA, Particles size analysis, etc.

Ion beam irradiation for surface modification of alignment layers in liquid crystal displays (액정 디스플레이 배향막을 위한 이온빔 표면조사에 관한 연구)

  • Oh, Byeong-Yun;Kim, Byoung-Yong;Lee, Kang-Min;Kim, Young-Hwan;Han, Jeong-Min;Lee, Sang-Keuk;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.04a
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    • pp.41-41
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    • 2008
  • In general, polyimides (PIs) are used in alignment layers in liquid crystal displays (LCDs). The rubbing alignment technique has been widely used to align the LC molecules on the PI layer. Although this method is suitable for mass production of LCDs because of its simple process and high productivity, it has certain limitations. A rubbed PI surface includes debris left by the cloth, and the generation of electrostatic charges during the rubbing induces local defects, streaks, and a grating-like wavy surface due to nonuniform microgrooves that degrade the display resolution of computer displays and digital television. Additional washing and drying to remove the debris, and overwriting for multi-domain formation to improve the electro-optical characteristics such as the wide viewing angle, reduce the cost-effectiveness of the process. Therefore, an alternative to non-rubbing techniques without changing the LC alignment layer (i.e, PI) is proposed. The surface of LC alignment layers as a function of the ion beam (IE) energy was modified. Various pretilt angles were created on the IB-irradiated PI surfaces. After IB irradiation, the Ar ions did not change the morphology of the PI surface, indicating that the pretilt angle was not due to microgrooves. To verify the compositional behavior for the LC alignment, the chemical bonding states of the ill-irradiated PI surfaces were analyzed in detail by XPS. The chemical structure analysis showed that ability of LCs to align was due to the preferential orientation of the carbon network, which was caused by the breaking of C=O double bonds in the imide ring, parallel to the incident 18 direction. The potential of non-rubbing technology for fabricating display devices was further conformed by achieving the superior electro-optical characteristics, compared to rubbed PI.

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