• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.7 no.1
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• pp.3-18
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• 1997

This study was conducted to evaluate desorption efficiencies by types of desorption solvent for polar and non-polar organic compounds collected on activated charcoal tubes. Analytes tested were toluene, m-xylene, isobutyl alcohol, n-butyl alcohol, cellosolve acetate, and butyl cellosolve. Three different concentration levels of spiked sample were made. Types of cosolvent mixed with the main solvent, $CS_2$, were methanol, pentanol, and dimethylformamide (DMF) and the cosolvent for methylenechloride was methanol. The amounts of cosolvent added to the main solvent were 1, 5, and 10% by volume (v/v%), respectively. The results were as follows: 1. For all mixed solvents except 1% methanol and 1% pentanol with $CS_2$, desorption efficiency significantly increased, compared with that of $CS_2$ alone. 2. Desorption efficiency increased by increasing analyte loading on charcoal tube regardless of mixed solvents used and the material polarity. 3. For all cosolvents mixed with $CS_2$ by 1% and 5% volume, desorption efficiency for non-polar compound was significantly higher than that of polar compound. For the 10% mixed solvents and the methylenechloride mixed with methanol, the results were opposite. 4. The lowest mean percent bias of 4.79% was obtained from the 5% DMF-$CS_2$ mixed solvent, followed by 4.82% from the 10% DMF-$CS_2$ solvent while the highest bias of 23.26% was from the solvent of $CS_2$ alone. Based on the results of this study, in order to increase desorption efficiency, it is recommended to add such cosolvents as methanol, pentanol, and DMF to $CS_2$, preferably 5% by volume for analyzing polar compounds collected in charcoal tubes.

• Korean Journal of Pharmacognosy
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• v.49 no.2
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• pp.108-112
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• 2018

Four quinolone alkaloids, 2-heptyl-4-quinolone (1), 2-nonyl-4-quinolone (2), 2-undecyl-4-quinolone (3), and 2-undecen-1'-yl-4-quinolone (4), together with two nitrogen derived benzoic acid derivatives, N-acetylanthranilic acid (5) and o-acetamidobenzamide (6) have been isolated from the Arctic bacterial strain, Pseudomonas aeruginosa. The structures of the compounds were determined by 1D and 2D NMR, and MS experiments, as well as by comparison of their data with published values. To the best of our knowledge, compounds 3-6 were isolated for the first time from P. aeruginosa.

• Korean Journal of Microbiology
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• v.54 no.1
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• pp.18-23
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• 2018

A new naturally occurring benzoic acid derivative, benzyl 2,4-di(benzyloxy)benzoate (1) and six known compounds (2-7) were isolated from the fungus, Preussia sp. found in frozen soil of the Himalaya Mountain. The structures of the new compound, together with the known compounds were determined by 1D-and 2D-NMR experiments, as well as comparison with published values. In addition, to the best of our knowledge, the known compounds 2-7 were isolated for the first time from the genus Preussia and the family Sporormiaceae. The isolates were evaluated for cancer chemopreventive potential based on their ability to inhibit nitric oxide (NO) production induced by lipopolysaccharide (LPS) in mouse macrophage RAW 264.7 cells in vitro. Compounds 1 and 2 inhibited NO production by 50.7% and 88.5% at a concentration of 100 mg/ml, respectively.

• Environmental Analysis Health and Toxicology
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• v.19 no.1
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• pp.109-117
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• 2004

The purpose of the present study was to examine the effect of diesel exhaust particles on human aortic vascular smooth muscle cells (VSMCs). DNA synthesis, cell viability and morphology of VSMCs after treatment of diesel exhaust particles (DEP) and fine particulate matter (PM$_{2.5}$) were assayed. PM$_{2.5}$ inhibited the DNA synthesis of VSMCs in a concentration -dependent manner, whereat DEP did not affect VSMCs up to 50$\mu\textrm{g}$/mL. These results were confirmed by morphological examination of VSMCs. PM$_{2.5}$ showed a dose-dependent cytotoxicity of VSMCs by MTT assay. Fraction 4 (organic acids) and fraction 8 (moderately polar compounds) showed the most potent inhibition of DNA synthesis of VSMCs, and fraction 7 (slightly polar compounds), fraction 9 (higher polar compounds), and fraction 6 (aromatic compounds) were next order. These results were confirmed by morphological examination of VSMCs. These results suggest that PM$_{2.5}$ inhibits the DNA synthesis of VSMCs through the cytotoxicity.oxicity.

• Elastomers and Composites
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• v.47 no.1
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• pp.54-64
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• 2012

Acrylonitrile was introduced in the emulsion SBR to increase compatibility between silica and rubber. AN-SBR/silica compounds showed faster vulcanization time and higher delta torque values than SBR 1721/silica compounds because interaction between nitrile group of AN-SBR and silanol group on the silica surface could make hydrogen bond that prevented adsorption of the accelerator on the silica surface, which improved the vulcanization reaction efficiency and enhanced the degree of crosslinking. AN-SBR/silica compound showed higher values in minimum torque than SBR 1721/silica compound during the vulcanization because AN-SBR has higher molecular weight than SBR 1721 in the raw material. When PEG was added to the SBR 1721 and AN-SBR compounds, vulcanization time was faster than SBR 1721 and AN-SBR compounds without PEG because PEG has a large number of ether linkages which show high compatibility with silanol group on the silica surface that prevented the adsorption of the accelerator and the ingredients on the silica surface, which improved the vulcanization reaction efficiency. In the mechanical properties, AN-SBR compounds showed higher modulus values at 100%, 300% than SBR 1721 compounds because interaction between nitrile group of AN-SBR and silanol group on the silica surface enhanced the degree of crosslinking. In the dynamic properties, AN-SBR compounds showed lower tan ${\delta}$ values at $0^{\circ}C$ than SBR 1721 compounds in accordance with the $T_g$ values. AN-SBR compounds showed lower tan ${\delta}$ values at $60^{\circ}C$ than SBR 1721 compounds because interaction between acrylonitrile and silica caused strong filler-rubber interaction that induced low energy dissipation by the filler-filler interaction.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.351.1-351.1
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• 2002

Heterocyclic compounds with oxygen atoms are known to have potent biological effect. The flavonoids. isoflavonoids. and coumarins which form the bulk of these compounds are very polar and have limited use as drugs which have to pass through membranes. The non-polar property is increased by exchange oxygen to selenium as a part of heterocyclic compound. Our group is focused on synthesizing selenoheterocyclic compound with the above property. (omitted)

• Ocean and Polar Research
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• v.32 no.4
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• pp.397-409
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• 2010

Herein, we compared the production rate of UV-absorbing compounds (mycosporine-like amino acids) and carotenoids in two phytoplankton species--Phaeocystis pouchetii and Porosira glacialis--which are the dominant species in Polar Regions under artificial UV radiation conditions. P. pouchetii exposed to UVR and PAR evidenced reductions in the carbon fixation rate, and was not significantly influenced by differing light conditions. However, the concentrations of UV-absorbing compounds and photo-protective pigments of P. pouchetii were increased with increasing exposure time, but P. glacialis maintained constant levels during the UVR exposure experiment. The production rates of MAAs showed a reverse phase between the two phytoplankton species. The carbon fixation rate of P. pouchetii cells was inhibited by exposure to UV radiation, but the production rates of MAAs in P. pouchetii were increased under UV radiation exposure. The carbon fixation rate and production rate of MAAs in P. glacialis were simultaneously inhibited under UV radiation exposure conditions. These results provide us with new information regarding the processes involved in the production of UV-absorbing compounds and photoprotective pigments in two phytoplankton species.

• Textile Coloration and Finishing
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• v.20 no.2
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• pp.29-37
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• 2008

Polar amino groups of the waste SS(silk-sericin) were modified by two isocyanate compounds of MOI[2-(methacryloyloxy)ethyl isocyanate] and AOI [2-(acryloyloxy)ethyl isocyanate]. When the MOISS (MOI-modified silk sericin) or AOISS(AOI-modified silk sericin) was pressed hot, vinyl groups in the MOI or AOI were polymerized and then the flexible and transparent films were obtained. Tensile moduli and strengths of the MOISS films were significantly improved as the MOI contents increased. By the addition of the isocyanate compounds, silk sericin films exhibited lower solubility to the distilled water($80^{\circ}C$) and also lower swell ratio to the distilled water(room temperature). In the effect of tensile properties and restraining the water swelling, MOI was better than AOI. BOD(biochemical oxygen demand)/TOD(theoretical oxygen demand) of the pure sericin film was almost 100% perfect level after 10 days immersion into the activated sludge. With increasing isocyanate content reacted with polar amino groups, BOD/TOD decreased. When more than 50 mol% of polar amino groups remained unreacted, sericin films could retain more biodegradability. Comparing with MOI from the viewpoint of biodegradability, AOI was more effective.

• Journal of Microbiology and Biotechnology
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• v.18 no.10
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• pp.1621-1629
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• 2008

Harmful algal blooms (HABs), commonly called red tides, are caused by some toxic phytoplanktons, and have made massive economic losses as well as marine environmental disturbances. As an effective and environment-friendly strategy to control HAB outbreaks, biological methods using marine bacteria capable of killing the harmful algae or algicidal extracellular compounds from them have been given attention. A new member of the $\gamma$-Proteobacteria, Hahella chejuensis KCTC 2396, was originally isolated from the Korean seashore for its ability to secrete industrially useful polysaccharides, and was characterized to produce a red pigment. This pigment later was identified as an alkaloid compound, prodigiosin. During the past several decades, prodigiosin has been extensively studied for its medical potential as immunosuppressants and antitumor agents, owing to its antibiotic and cytotoxic activities. The lytic activity of this marvelous molecule against Cochlodinium polykrikoides cells at very low concentrations ($\sim$l ppb) was serendipitously detected, making H. chejuensis a strong candidate among the biological agents for HAB control. This review provides a brief overview of algicidal marine bacteria and their products, and describes in detail the algicidal characteristics, biosynthetic process, and genetic regulation of prodigiosin as a model among the compounds active against red-tide organisms from the biochemical and genetic viewpoints.

• Journal of the Korean Wood Science and Technology
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• v.30 no.4
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• pp.80-86
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• 2002

Volatile compounds in three different kinds of crude vinegars obtained from oak (Quercus serrata), bamboo (phyllostachys) and pine (Pinus densiflora) species were analyzed by the solid-phase microextraction (SPME) method. A total of 264 peaks were detected on the chromatograms obtained from the polar (CBP 20) and the nonpolar (CBP 1) columns, which were used for analyzing the volatile compounds in these vinegars. The major volatile compounds identified by using the polar column were 2-butanone, acetic acid, guaiacol, phenol, cresols, 4-ethyl guaiacol, 4-ethyl phenol, and syringol. Using the nonpolar column, seven compounds could be identified: 1,2-dimethoxybenzyl alcohol, 1-hydroxy-2-butanone, 1-(2-furanyl)-1-propane, ethisolide, furfuryl acetate, 1,2-dimethoxybenzene, phenyl acetate. The volatile compounds were classified into five groups: phenols, neutral compounds, organic acids, esters and others. The phenols were the main component and comprised 49~65% of the volatile compounds of these vinegars. In the case of bamboo vinegar, the proportion of the phenols in the volatile compounds was lower than that of the two wood vinegars. However, the proportions of the neutral compounds and the organic acids were higher than those of the wood vinegars. Therefore, it seems that these differences of the proportions of the volatile compounds would make a certain difference of a smoke flavor between the bamboo vinegar and the wood vinegars.