• Journal of Radiopharmaceuticals and Molecular Probes
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• v.4 no.1
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• pp.16-21
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• 2018

Organoboron compounds and their derivatives are synthetically versatile building blocks because they are readily available, stable, and highly useful for potential organic transformations. Arylboronic esters are of particular interest due to their well-established synthetic methods: transition metal catalyzed borylations of aryl halides. However, the use of aryl halides as an electrophile has one serious disadvantage: formation of toxic halogenated byproducts. A promising alternative substrate to aryl halides would be phenol derivatives such as aryl ethers, esters, carbamates and sulfonates. The phenol derivatives involve several advantages: their abundance, relatively low toxicity and versatile synthetic application. However, utilization of the aryl methyl ether, which is one of the simplest phenol derivatives, remains as a challenge, as C-OMe bond activation requires high activation energy and methoxides are not good leaving groups. Nevertheless, there have been a significant recent progress on ipso-borylation of aryl methyl ether including Martin's nickel catalysis. Here, we review the current advance on the borylation of carbon-oxygen bonds of unactivated C-OMe bond in aromatic compounds.

• Proceedings of the Microbiological Society of Korea Conference
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• 2002.10a
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• pp.27-30
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• 2002

Ralstonia eutrupha JMP134 is a well-known soil bacterium which can metabolite diverse aromatic compounds and xenobiotics, such as phenol, 2,4-dichlorophenoxy acetic acid (2, 4-D), and trichloroethylene (TCE), etc. Phenol is degraded through chromosomally encoded phenol degradation pathway. Phenol is first metabolized into catechol by a multicomponent phenol hydroxylase, which is further metabolized to TCA cycle intermediates via a meta-cleavage pathway. The nucleotide sequences of the genes for the phenol hydroxylase have previously been determined, and found to composed of eight genes phlKLMNOPRX in an operon structure. The phlR, whose gene product is a NtrC-like transcriptional activator, was found to be located at the internal region of the structural genes, which is not the case in most bacteria where the regulatory genes lie near the structural genes. In addition to this regulatory gene, we found other regulatory genes, the phlA and phlR2, downstream of the phlX. These genes were found to be overlapped and hence likely to be co-transcribed. The protein similarity analysis has revealed that the PhlA belongs to the GntR family, which are known to be negative regulators, whereas the PhlR2 shares high homology with the NtrC-type family of transcriptional activators like the PhlR. Disruption of the phlA by insertional mutation has led to the constitutive expression of the activity of phenol hydroxylase in JMP134, indicating that PhlA is a negative regulator. Possible regulatory mechanisms of phenol metabolism in R. eutropha JMP134 has been discussed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.4
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• pp.1000-1006
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• 2011

We examined the effects of various phenolic compounds, Ti plasmids(octopine, nopaline) and A. tumefaciens on the vir gene expression. Nine phenolic compounds were tested using 3 types of Ti plasmid and 3 strains of A. tumefaciens on the vir gene expression. It was also investigated how the levels of vir gene expression could be related to specific phenolic compounds. Six phenolic compounds as 4-hydroxyacetophenone, phenol, catechol, resorcinol, acetosyringone and vanillin had exhibited a strong effect on the vir gene expression of A. tumefaciens MW107 containing nopaline Ti plasmid. The vir genes of A. tumefaciens MW105 and MW108 containing octopine Ti plasmids were remarkably stimulated only by acetosyringone. Thus, it appeared that the vir gene inducing abilities were differed by the kinds of phenolic compounds, A. tumefaciens and Ti plasmids.

• Journal of Life Science
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• v.13 no.1
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• pp.99-104
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• 2003

Aromatic compounds are of major concern among environmental pollutants due to their toxicity and persistence. To monitor aromatic compounds in a real time with a better sensitivity, a new method of SPR (surface plasmon resonance) based on DNA chip (Biacore 3000) was developed here. It is thought that CapR regulatory protein as a complex with phenol, could bind to their corresponding promoter, Po. Biotinylated DNA oligomers for the promoter was synthesized by PCR and coupled onto streptoavidin-linked CM5-chip. CapR regulatory proteins were purified after cloning their genes in pET21a (+) vector and expressing proteins. The interaction was assessed by the system where the regulatory proteins flowed with or without phenol through the cells of DNA chip. CapR regulatory protein even in the presence of phenol had no response to its promoter, Po, suggesting that other factor(s) might be required for the activation of Po promoter. The present work reveals a promising possibility of the SPR-based DNA chip in monitoring specific environmental pollutants in a real time.

• Journal of Bio-Environment Control
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• v.20 no.1
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• pp.14-20
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• 2011

Objective of this research was to investigate the volatile aroma compounds and phenol contents for preservative effects. Aerial part of 5 Korean natured species of thyme located in Jeju alpine, jeju middle mountain, Kyeonggido, Ulleung island, and Gangwondo was analyzed by thermal desorption gas chromatograph mass spectrometer (TD-GC-MSD) method. Jeju middle mountain thyme was relatively high 62 species and has been investigated a high concentration of $7365.22{\mu}g/m^3$ contents according to the quantitative analysis. Total phenol contents containing thymol and carvacrol of Jeju middle mountain thyme were relatively high and showed 35.92%.

• YAKHAK HOEJI
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• v.15 no.3_4
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• pp.87-92
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• 1971

Fourteen novel N,N'-disubstitued thiourea derivatives were synthesized by Hugershof reaction. Antitubercular activities of ten compounds against Mycobacterium tuberculosis H$_{37}$ Rv were tested and was found tat 1-cyclohexyl-3-(4-benzenesulfonepiperidide)-2-thiourea was considerably active at 1mg/ml and 1-$\alpha$-naphthyl-3-(4-benzenesulfonepiperidide)-2-thiourea was slightly active at 1mg/ml. Antibacterial activity of the newly synthesized compounds against E. coli, Sta. aureus and Streptococcus hemolyticus were also tested. 1-cyclohexyl-3-(4-benzenesulfonepiperidide)-2-thiourea was makedly active against E. coli, Sta, aureus and Streptococcus hemolyticus; Phenol coefficients against E. coli, Sta, aureus and Streptococcus hemolyticus were 30,17.5 and 21.3, respectively. 1,1'-p-phenylene-3,3'bis[N-(2-thiazolyl)-sulfamylphenyl]-2,2'-dithiourea and 1-$\alpha$-naphthyl-3-(4-benzenesulfonepiperidide)-2-thiourea were considerably active against E. coli: phenol coefficients, 18.8 and 37.5 respectively. 1-(4-ethoxyphenyl)3-(4-sulfamylphenyl)-2-thiourea was active against Streptococcus hemolyticus: phenol coefficients, 22.5. 1-$\alpha$-naphthyl-3-(4-sulfamylphenyl)-2-thiourea, 1-$\betha$-naphthyl-3-[4-N-(2-thiazolyl)-sulfamylphenyl]-2-thiourea and 1-$\alpha$-naphthyl-3-(4-benzenesulfonepiperidide)-2-thiourea were active against Sta. aureus: phenol coefficients, 17.5, 20.0 and 18.8 respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.2
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• pp.85-94
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• 1988

This experiment was carried out to obtain the basic data for removal the astringency and off-flavor in soybean milk, by means of soaking of soybean in NaOH and $NaHCO_3$ solutions. The changes of phenolic compounds in soybean during soaking were investigated with HPLC and also the changes of flavor and sensority of soybean milk, prepared from soaked soybean were studied. Phenolic compounds of soybean were identified as chlorogenic, p-hydroxybenzoic, p-coumaric, ferulic and gentisic acid and, chlorogenic acid content was greater than the others. The chlorogenic acid of soybean was mainly neutral type and the other compounds were almost acidic type. Up to 85% of the chlorogenic acid was removed by soaking of soybean in 0.1% of NaOH solution for 8 hrs. Phenolic compounds of soybean was almost removed by soaking in 0.1% of NaOH solution at $90^{\circ}C$ for 1 hr. Chemical composition of soybean milks prepared from soaking of soybean in water, 0.1% NaOH and 0.5% $NaHCO_3$ solution were similar. Hexanol content of beany flavor in soybean milk was increased by soaking of soybean in NaOH solution, where as hexanal, propanal, pentanal contents were removed up to 60%. Color of soybean prepared from soaking of soybean in NaOH solution at high temperature were deep yellow but were high whiteness in soybean milk prepared from soaking of soybean in water at low temperature. Sensority of soybean milk prepared from soaking of soybean in 0.1% of NaOH solution at $90^{\circ}C$ for 1 hr was more favorable than the others.

• Journal of Environmental Science International
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• v.11 no.5
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• pp.437-443
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• 2002

The chemical behavior and properties of the redox state of environmental pollutants were investigated using electrochemical methods. Cyclic voltammograms were performed on the compounds to measure the variations in the redox reactions. Temperature and pH were established as influencing the redox potential and current. The electrode reactions were a mixture of quasi-reversible and irreversible Precesses, which changed according to the reaction current. Although the Co(BPA)$_2$ and Cu(BPA)$_2$ compounds were not found to dissociate in wastewater, they were very unstable(K=1.02).

• Journal of Korea Foresty Energy
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• v.18 no.1
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• pp.17-24
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• 1999

This study was conducted to examine the change in the structure of the lignin during liquefaction of kraft pulp lignin in Pinus korainsis and lignin sulfonic acid. The lignin liquefied compounds were extracted with chloroform from aqueous, liquefied lignins. Through the examination by IR, H($^{13}$C) - NMR and GC-MS spectrometers, phenolic compounds such as diguaiacol, acetic acid phenyl ester, phenol, 1-phenyl ethanone were identified with many of unknown phenolic compounds.

• Korean Journal of Food Science and Technology
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• v.8 no.2
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• pp.80-84
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• 1976

Two varieties, Lasoda and Sebago potatoes, were studied. Different cooking methods, conventional oven baking at $218^{\circ}C$ and microwave oven baking, have been used to compare the retention of the phenolic compounds. Peeled cortex samples of fresh and cooked potatoes were analyzed for total phenols, phenolic constituents, and moisture loss. Phenolic content was higher in fresh potatoes than in cooked potatoes. Laasoda had higher phenolic content (3. 63mg) than Sebago (1. 71mg). Potatoes with higher phenols (Lasoda) also had larger quantities of chlorogenic acid. There was a greater moisture loss in conventional oven baking potatoes than in microware oven.