• 대한화학회지
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• 제56권2호
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• pp.264-273
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• 2012

Five derivatives of phenylthiourea namely: 1-(4-methoxyphenyl)-3-phenylthiourea (1), 1-(4-methylphenyl)-3- phenylthiourea (2), 1-(4-bromophenyl)-3-phenylthiourea (3), 1-(4-chlorophenyl)-3-phenylthiourea (4) and 1-phenylthiourea (5) have been evaluated as new inhibitors for the corrosion of carbon steel in 2 M HCl solution using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. Potentiodynamic polarization measurements showed that these derivatives are mixed-type inhibitors. The inhibition efficiency was found to increase with inhibitor concentration and decreases with rise in temperature. The thermodynamic parameters of adsorption and activation were determined and discussed. Nyquist plots showed depressed semicircles with their centre below real axis. The adsorption process of studied derivatives on carbon steel surface obeys Temkin adsorption isotherm. The synergistic effect of these derivatives and some anions is discussed from the viewpoint of adsorption models. The electrochemical results are in good agreement with the calculated quantum chemical HOMO and LUMO energies of the tested molecules.

• Journal of Microbiology and Biotechnology
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• 제28권2호
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• pp.298-304
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• 2018

The single-vessel multienzyme UDP-${\alpha}$-$\text\tiny{D}$-glucose recycling system was coupled with a forward glucosylation reaction to produce novel glucose moiety-conjugated derivatives of different tetracycline antibiotic analogs. Among five tetracycline analogs used for the reaction, four molecules (chlorotetracycline, doxytetracycline, meclotetracycline, and minotetracycline) were accepted by a glycosyltransferase enzyme, YjiC, from Bacillus licheniformis to produce glucoside derivatives. However, the enzyme was unable to conjugate sugar units to rolitetracycline. All glucosides of tetracycline derivatives were characterized by ultraviolet absorbance maxima, ultra-pressure liquid chromatography coupled with photodiode array, and high-resolution quadruple time-of-flight electrospray mass spectrometry analyses. These synthesized glucosides are novel tetracycline derivatives.

• Wind and Structures
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• 제9권2호
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• pp.159-178
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• 2006

For the slender and flexible cable supported bridges, identification of all the flutter derivatives for the vertical, lateral and torsional motions is essential for its stability investigation. In all, eighteen flutter derivatives may have to be considered, the identification of which using a three degree-of-freedom elastic suspension system has been a challenging task. In this paper, a system identification technique, known as covariance-driven stochastic subspace identification (COV-SSI) technique, has been utilized to extract the flutter derivatives for a typical bridge deck. This method identifies the stochastic state-space model from the covariances of the output-only (stochastic) data. All the eighteen flutter derivatives have been simultaneously extracted from the output response data obtained from wind tunnel test on a 3-DOF elastically suspended bridge deck section-model. Simplicity in model suspension and measurements of only output responses are additional motivating factors for adopting COV-SSI technique. The identified discrete values of flutter derivatives have been approximated by rational functions.

• 통합자연과학논문집
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• 제8권3호
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• pp.204-208
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• 2015

Pyrazole, ${\beta}$-lactam, salicidine, pyren and oxazole derivatives exhibit a broad spectrum of biological activities such as antimicrobial, anti-inflammatory and antitumor activities. With growing application on their synthesis and bioactivity, chemists and biologists in recent years have considerable attention on the research of these derivatives. In the view of potential importance of these derivatives, we have crystallized few of the derivatives and its report has been published. The present study focuses on docking studies of these derivatives against COX-2 enzyme. Docking studies using Schrodinger's GLIDE reveals that these derivatives shows better binding energy and score in the defined active site. These results may provide a guiding role to design a lead molecule which may reduce inflamation.

• Archives of Pharmacal Research
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• 제12권3호
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• pp.201-206
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• 1989

The reaction of acetoacetanilide (1) with the $\alpha$-cyanocinnamonitrile derivatives 2 yielded the Michael adducts 4 which could be converted into the pyrano [2, 3, -c] pyrazole derivatives 5 via their reaction with hydrazine hydrate. Cyclisation of 4 afforded the derivatives 10. The pyranopyrazoles 9 reacted with different activated nitrile derivatives (3a-c) to give the pyrano [2, 3-c] pyridine derivatives 13. 16 and 19 respectively. The biological activity of the synthesised heterocyclic derivatives was investigated and discussed.

• 약학회지
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• 제36권1호
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• pp.36-39
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• 1992

In a continuous study for the developing of the anticariogenic agents, 3,3'-diacyl-4,4'-biphenol derivatives (Fig. 2, 2 and 3) and 3,3'-bis-(1-hydroxyalkyl)-4,4'-biphenol (Fig. 3, 4 and 5) derivatives are synthesized successively from 4,4'-diphenol (Fig. 2, 1). The synthesized compounds are tested for their antibacterial activity against a cariogenic bacterium, Streptococcus mutans OMZ 176. The acyl derivatives, 2 and 3, do not show antibacterial activity, but the hydroxyalkyl derivatives, 4 and 5, reduced from the acyl group of 2 and 3, show the activity. The antibacterial activity of 2 and 3 may be inhibited due to intramolecular hydrogen bonding between the acyl group and the hydroxyl one (Fig. 4).

• 통합자연과학논문집
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• 제8권2호
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• pp.111-116
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• 2015

Liquid chromatographic enantiomer separation of ${\alpha}$-amino acid esters as nitrobenzoxadiazole (NBD) derivatives was performed using several chiral stationary phases (CSPs) based on polysaccharide derivatives under fluorescence detection. For enantiomer separation by normal HPLC, the non-aqueous derivatization method of ${\alpha}$-amino acid esters for NBD analytes was introduced. Among the six CSPs used in this study, the performance of Chiralpak IA was superior for enantiomer resolution of NBD derivatives of several ${\alpha}$-amino acid methyl esters. Also the convenient analytical method using polysaccharide-derived CSPs developed in this study was applied to determine the optical purity of ${\alpha}$-amino acids esters. It was investigated that the enantiomeric impurity levels of 0.02-1.73% were found after determination of enantiomeric purities of several commercially available L-amino acid methyl esters. It is expected to be quite useful for enantiomer separation of other ${\alpha}$-amino acid esters as NBD derivatives by normal HPLC.

• 약학회지
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• 제45권5호
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• pp.431-436
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• 2001

Antifungal activities of trans-cinnamaldehyde (CA) derivatives including commercial CA derivatives as well as synthesized CA derivatives against various human pathogenic fungi were investigated. Among the derivatives tested, -chlorocinnamaldehyde, $\alpha$-bromocinnamaldehyde and 7-phenyl-2,4,6-heptatrienal were more potent than CA in antifungal activity, $\alpha$-Bromocinnamaldehyde was the most effective in inhibiting the growth of representative fungi of dermatomycosis with minimum inhibitory cocentration(MIC) of 0.61~9.76$\mu\textrm{g}$/ml . In the structure-activity relationship, introduction of the chlorine and bromine group into the C-2 of CA resulted in the decrease of MIC. Derivative with more double bonds exhibited the increase of antifungal activity against various pathogenic fungi.

• Archives of Pharmacal Research
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• 제16권4호
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• pp.322-326
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• 1993

For the development of new antinflammatory and analgesic drugs, new 5-alkylthio (or sulfonyl) methyl-5-m-methoxyphenylhydantoin-3-acetic acid derivatives(alkyl; ethyl, propyl, butyl) were prepared. The 5,5 -disubstituted hydantoins which were used as starting materials, were prepared acording to Bucherer-Berg method. The reaction of ethyl chloroacelate with these compounds gave 3-acetate and the subsequent hydrolysis with dilute sodium hydroxide resulted in hydantoin 3-acetate and the subsequent hydrolysis with dilute sodium hydroxide resulted in hydantoin 3-acetic acid derivatives. Through the same procedure of equivalent hydroxide resulted in hydantoin 3-acetic acid derivatives. Through the same procedure of equivelent hydantions or the oxidation of 5-alkylthiohydantoin ocmpounds described above, 5-alkylsulfonylme-thyl-5-m-methoxyphenylhydantoin-30acetic acid derivatives were also synthesized.

• 미생물학회지
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• 제21권4호
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• pp.185-190
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• 1983

Twelve Microorganisms capable of utilizing diaminododecane were isolated from the soil by enrichment culture technique. Seven strains of these were identified as Corynebacterium. The isolated strains were tested for the ability to utilize as carbon source, 10 different kind of alkane derivatives containing CN, $NH_2$, Cl, and SH groups. Laurylcyanide, dicyanooetane, chlorodecane, and dichlorodecane were not utilized by any of the isolated strains; putrescine dihydrochloride, cadaverine dihydrochloride, diaminododecane, and n-dodecane were utilized by all of the isolated strains; and all of the isolated strains except DAD 2-3 could utilize dodecylmercaptan. The alkane derivatives that did not serve as ,growth substrates were tested further in oxidation tests using resting cell preparation. Alkane derivatives that are being oxidized by all of the isolated strains are laurylcyanide and dichlorodecane. Dicyanooctane was also oxidized by all of the isolated strains except DAD 30L, chlorodecane was the only oxidized by the three isolated strains. The most remarkable substrate that is being oxidized is dichlorodecane containing CN groups diterminally. Evidence obtained with thin layer chromatography of ,ethyl acetate extracts of culture broth of isolated strains grown in some alkane derivatives shows that these alkane derivatives are degraded.