• The Korean Journal of Pesticide Science
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• v.11 no.2
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• pp.72-81
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• 2007

Quantitative structure-activity relationships (QSARs) on the pre-emergency herbicidal activity and reactivity of a series of new O,O-dialkyl-1-phenoxyacetoxy-1-methylphosphonates (S) analogues against seed of cucumber (Cucumus Sativa) were discussed quantitatively using 2D-QSAR and HQSAR methods. The statistical values of HQSAR model were better than that of 2D-QSAR model. From the frontier molecular orbital (FMO) interaction between substrate molecule (S) and $BH^+$ ion (I) in PDH enzyme, the electrophilic reaction was superior in reactivity. From the effect of substituents, $R_2$-groups in substrate molecule (S) contributed to electrophilic reaction with carbonyl oxygen atom while X, Y-groups contributed to nucleophilic reaction with carbonyl carbon atom. And the influence of X,Y-groups was more effective than that of $R_2$-groups. As a results of 2D-QSAR model (I & II) and atomic contribution maps with HQSAR model, the more length of X, Y-groups is longer, the more herbicidal activity tends to increased. And also, the optimal ${\epsilon}LUMO$ energy, $({\epsilon}LUMO)_{opt.}$=-0.479 (e.v.) of substrate molecule is important factor in determining the herbicidal activity. It is predicted that the herbicidal activity proceeds through a nucleophilic reaction. From the analytical results of 2D-QSAR and HQSAR model, it is suggested that the structural distinctions and descriptors that contribute to herbicidal activities will be able to applied new herbicide design.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.12
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• pp.831-836
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• 2014

One-dimensional (1D) photonic crystals (PCs) were prepared by $TeO_x(2<x<3)/SiO_2$ with the difference refractive index, and fabricated by sputtering technique from a $TeO_2$ and $SiO_2$ target. The $TeO_x$(2$Ar:O_2=40:10$). A 10-pair $TeO_x(2<x<3)/SiO_2$ 1D PCs were fabricated with the structure parameters of filling factor=0.5185, and period=410 nm. The properties of 1D PCs with and without a defect layer were evaluated by UV-VIS-NIR. A normal mode 1D PC have a photonic band gap (PBG) in the near infrared (NIR) region from 1,203 to 1,421 nm. In the case of 1D PC containing a defect layer, a defect level appears at 1,291 nm. The measured transmittance (T) spectra are nearly corresponding to calculated results. After He-Cd laser exposure, the defect level is shifted from 1,291 nm to 1,304 nm.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.2089-2094
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• 2003

The flow around a circular cylinder was controlled by attaching O-rings to reduce drag force acting on the cylinder. Four experimental models were tested in this study; one smooth cylinder of diameter D (D=60mm) and three cylinders fitted with O-rings of diameters d=0.0167D, 0.05D and 0.067D with pitches of PPD=1D, 0.5D and 0.25D. The drag force, mean velocity and turbulent intensity profiles in the near wake behind the cylinders were measured for Reynolds numbers based on the cylinder diameter in the range of $Re_D=7.8{\times}10^3{\sim}1.2{\times}10^5$. At $Re_D=1.2{\times}10^5$, the cylinder fitted with O-rings of d=0.0167D in a pitch interval of 0.25D shows the maximum drag reduction of about 5.4%, compared with the smooth cylinder. The drag reduction effect of O-rings of d=0.067D is not so high. For O-ring circulars, as the Reynolds number increases, the peak location of turbulence intensity shifts downstream and the peak magnitude is decreased. Flow field around the cylinders was visualized using a smoke-wire technique to see the flow structure qualitatively. The size of vortices and vortex formation region formed behind the O-ring cylinders are smaller, compared with the smooth cylinder.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1721-1724
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• 2011

• Korean Journal of Materials Research
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• v.9 no.8
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• pp.849-853
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• 1999

In the study, superconducting properties of $Bi_2$-x(sub)$LSr_2$Ca(sub)1+x(sub)$LCu_2$O(sub)8+d (x(sub)L=0, 0.05, 0.1, 0.2) films prepared by the LPE method was investigated. The peak decompositions of Sr3d and Ca2p XPS spectra, together with the EPMA results, elucidated the occupancies of Bi, Sr and Ca atoms on the SrO- and Ca-layers. The lattice parameter c monotonically increased with increasing x(sub)L for $0\leq$x(sub)L$\leq$0.2. The superconducting critical temperature T(sub)c showed a maximum value around x(sub)L=0.1. The x(sub)L dependence of the superconducting critical temperature T(sub)c and the lattice parameter c are explained by the changes of the excess oxygens in the BiO-layer. Since distribution and deficiency of the atoms in SrO-layer have influenced on superconducting properties and crystal structure.

• Korean Journal of Pharmacognosy
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• v.51 no.1
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• pp.55-64
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• 2020

In this study, 15 compounds were elucidated from the hot-water extract of Perillae Folium. Fifteen isolates were determined to be protocatechuic acid (1), caffeic acid (2), (R)-rosmarinic acid (3), (S)-shisoflavanone A (4), luteolin-7-O-β-D-glucuronopyranoside (5), scutellarein-7-O-β-D-glucuronopyranoside (6), apigenin-7-O-β-D-glucuronopyranosyl(1→2)-O-β-D-glucuronopyranoside (7), luteolin-7-O-β-D-glucuronopyranosyl(1→2)-O-β-D-glucuronopyranoside (8), kelampayoside A (9), trans-N-feruloyloctopamine (10), 3-(4-hydroxy-3-methoxyphenyl)-N-[2-(4-hydroxyphenyl)-2-methoxyethyl]acrylamide (11), perilloside C (12), perilloside A (13), (6S,9R)-9-hydroxy-megastigma-4,7-dien-3-one-9-O-β-D-glucopyranoside (14) and (6S,9R)-roseoside (15) through spectroscopic evidences. The HPLC analysis revealed that hot-water extract of Perillae Folium contained caffeic acid, rosmarinic acid and glycosides of apigenin, luteolin and scutellarein as main constituents.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.3
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• pp.313-316
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• 1993

The structures of dioscin(1) and saponin P-d(2), isolated from the subterranean part of Allium fistulosum, were determined as diosgenin 3-O-$\alpha$-L-rhamnopyranosyl (1longrightarrow2)-[$\alpha$-L-rhamnopyranosyl (1longrightarrow4)]-$\beta$-D-glucopyranoside (1, ) and diosgenin 3-O-$\alpha$-L-rhamnopyranosyl (1longrightarrow4)-$\alpha$-L-rhamnopyranosyl(1longrightarrow4)［$\alpha$-L-rhamno-pyranosyl (1longrightarrow2)]-$\beta$-D-glucopyranoside (2) by spectroscopic and chemical degradational methods. The prosa-pogenin(4), which was provided on partial hydrolysis of 2, was not reported in previous literature.

• Journal of the Korean Wood Science and Technology
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• v.45 no.3
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• pp.250-257
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• 2017

Eight hydrolyzable tannin compounds, such as gallic acid (1), methyl gallate (2), kurigalin (3), 1,2,3,6-tetra-O-galloyl-${\beta}$-D-(+)-glucose (4), 1,2,3,4,6-penta-O-galloyl-${\beta}$-D-(+)-glucose (5), 6-m-digalloyl-1,2,3,4,6-penta-O-galloyl-${\beta}$-D-(+)-glucose (6), isocorilagin (7), macabarterin (8), were isolated from the EtOAc and $H_2O$ soluble fractions of Katsura tree (Cercidiphyllum japonicum) leaves, wood and bark. Then antioxidative and anti-inflammatory activity were evaluated on the each isolated compound. The antioxidative test was DPPH radical scavenging activity and all of the isolated compounds indicated much higher antioxidative values compare to the controls, BHT and ${\alpha}$-tocopherol. In the anti-inflammatory test measuring nitric oxide (NO) inhibition activity, methyl gallate, 1,2,3,6-tetra-O-galloyl-${\beta}$-D-glucose and 1,2,3,4,6-penta-O-galloyl-${\beta}$-D-glucose inhibited NO production, and especially, methyl gallate showed high inhibition activity. However, the anti-inflammatory activity of the hydrolyzable tannins did not show positive effect. Based on the above results, the hydrolyzable tannins of katsura tree may be used as one of the natural biomass sources that can substitute with the synthetic antioxidant.

• Archives of Pharmacal Research
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• v.23 no.2
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• pp.159-162
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• 2000

A new stilbene diglycoside, piceatannol-3, 4'-O-$\beta$-D-diglucopyranoside (I), together with desoxyrhaponticin (II), emodin-1-O-$\beta$-D-glucopyranoside (III), and physcion-8-O-b-D-gluco-pyranoside (IV), were isolated from the rhizomes of cultivated Korean rhubarb rhizomes(Rheum undulatum), Jong DaeWhang, and the structures of 1-IV were identified on the basis of chemical and spectral evidences.

• Korean Journal of Pharmacognosy
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• v.21 no.2
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• pp.111-120
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• 1990

Five biflavones and sevenflavonolglycosideswereisolatedfromtheleaves of Ginkgo biloba. They were sciadopitysin(1), ginkgetin(2), isoginkgetin(3), bilobetin(4), amentoflavone(5), kaempferol 3-O-[$6'-O-{\rho}-coumaroyl-{\beta}-_D-glucopyranosyl(1{\rightarrow}2)-{\alpha}-_Lrhamnopyranoside$](6), quercetin 3-O-[$6'-O-{\rho}-coumaroyl-{\beta}-_D-glucopyranosyl(1{\rightarrow}2)-{\alpha}-_Lrhamnopyranoside$](8), rutinosides of kaempferol(7), isorhamnetin(9), quercetin(10), laricitrin(11), and kaempferol 3-O-($2',6'-{\alpha}-_L-dirhamnopyranosyl-{\beta}-_{D}-glucopyranoside$)(12). The structures were established by spectroscopic and chemical methods.