• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.6
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• pp.953-957
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• 2002

Volatile compounds from shrimp whole body (SWB) and shrimp shell waste (SSW) were isolated, and identified by the combination of SDE (simultaneous steam distillation and solvent extraction), GC (gas chromatography, HP-5890 plus)and MSD (mass selective detecter) or olfactometry. The peak numbers isolated from SWB and SSW were 20 and 46, respectively. The amounts of the volatile compounds isolated from SSW were higher than those of SWB. SWB produced more low-boiling compounds below 7$0^{\circ}C$ and SSW did more high boiling compounds over 10$0^{\circ}C$. The volatile compounds identified from SSW were 9 pyrazines,5 acids,4 aldehydes, and 4 alcohols. These volatile compounds were evaluated by aroma extraction dilution analysis and gas chromatography olfactometry (GCO). Some compounds which were not detected by GC-FID and GC-MSD were found to be a strong shrimp flavor of log$_3$ FD 3 value by GCO. Strong shrimp odors were detected in low temperature while nutty aromatic odors and unpleasant oily smells were found in high temperature.

• Journal of Microbiology and Biotechnology
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• v.23 no.2
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• pp.218-224
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• 2013

The aldo-keto reductases catalyze reduction reactions using various aliphatic and aromatic aldehydes/ketones. Most reductases require NADPH exclusively as their cofactors. However, NADPH is much more expensive and unstable than NADH. In this study, we attempted to change the five amino acid residues that interact with the 2'-phosphate group of the adenosine ribose of NADPH. These residues were selected based on a docking model of the YOL151W reductase and were substituted with other amino acids to develop NADH-utilizing enzymes. Ten mutants were constructed by site-directed mutagenesis and expressed in Escherichia coli. Among them, four mutants showed higher reductase activities than wild-type when using the NADH cofactor. Analysis of the kinetic parameters for the wild type and mutants indicated that the $k_{cat}/K_{m}$ value of the Asn9Glu mutant toward NADH increased 3-fold. A docking model was used to show that the carboxyl group of Glu 9 of the mutant formed an additional hydrogen bond with the 2'-hydroxyl group of adenosine ribose. The Asn9Glu mutant was able to produce (R)-ethyl-4-chloro-3-hydroxyl butanoate rapidly when using the NADH regeneration system.

• 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.

• Journal of Microbiology and Biotechnology
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• v.25 no.7
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• pp.1129-1135
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• 2015

The synthesis of gold nanoparticles has gained tremendous attention owing to their immense applications in the field of biomedical sciences. Although several chemical procedures are used for the synthesis of nanoparticles, the release of toxic and hazardous by-products restricts their use in biomedical applications. In the present investigation, gold nanoparticles were synthesized biologically using the culture filtrate of the filamentous fungus Alternaria sp. The culture filtrate of the fungus was exposed to three different concentrations of chloroaurate ions. In all cases, the gold ions were reduced to Au(0), leading to the formation of stable gold nanoparticles of variable sizes and shapes. UV-Vis spectroscopy analysis confirmed the formation of nanoparticles by reduction of Au³⁺ to Au⁰. TEM analysis revealed the presence of spherical, rod, square, pentagonal, and hexagonal morphologies for 1 mM chloroaurate solution. However, quasi-spherical and spherical nanoparticles/heart-like morphologies with size range of about 7-13 and 15-18 nm were observed for lower molar concentrations of 0.3 and 0.5 mM gold chloride solution, respectively. The XRD spectrum revealed the face-centered cubic crystals of synthesized gold nanoparticles. FT-IR spectroscopy analysis confirmed the presence of aromatic primary amines, and the additional SPR bands at 290 and 230 nm further suggested that the presence of amino acids such as tryptophan/tyrosine or phenylalanine acts as the capping agent on the synthesized mycogenic gold nanoparticles.

• Korean Journal of Food Science and Technology
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• v.26 no.5
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• pp.500-506
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• 1994

For comparison of beef quality, four kinds of beef (Korean native cattle beef, dairy cattle beef, imported beef, cross-bred beef) were investigated through tenderness, juiciness and flavor related components measurement and organoleptic tests. Flavor related chemical components such as NPN, IMP, free fatty acid and free amino acids were analyzed, water holding capacity, contents of hydroxyproline and intramuscular fat were measured for evaluation of beef tenderness. Instron was also used for measuring beef tenderness as an objective method. Triangle test and descriptive analysis test were conducted for comparison and evaluation of preference of various beef samples. In hardness analysis using Instron, imported and cross-bred beefs had higher value than that of Korean native cattle or dairy cattle beef. Water holding capacity and pH of Korean cattle beef was higher than that of others. The intramuscular fat content of Korean cattle beef was highest, so it was expected juicier than other beef. In flavor related compound analysis, NPN content of Korean native cattle beef was the lowest, which shows it spent the least time among sample meats after slaughter. IMP, hypoxantine and inosine were most abundant in Korean native cattle beef. In free amino acids analysis showed that the proportion of basic acid and aromatic acid content of Korean native cattle beef was highest, whereas that of sulfur containing amino acid of imported beef was highest. TBA value of Korean native cattle beef was the lowest, and analysis of fatty acid composition revealed that the proportion of unsaturated fatty acid of Korean native cattle beef was higher than imported and dairy cattle beef, but similar to cross-bred beef. Organoleptic test was performed by triangle test and descriptive analysis. In triangle test, most panelist could distinguish Korea native cattle beef from imported beef and cross-bred beef, imported beef from cross-bred beef. In descriptive analysis which relys on subjective standards of panelists, there was no difference among beef in aroma, flavor and tenderness except juiciness. Even though contents of non volatile flavor compounds in Korean native cattle beef were higher than those of other beef samples, there were no significant differences in subjective panel test. The results showed that Korean consumers do not have common standards for beef quality evaluation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.1
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• pp.88-103
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• 2009

The volatile and semi-volatile compounds of 5 accessions of domestic scented and 25 accessions of introduced scented were extracted by solid phase microextraction (SPME) and analyzed by gas chromatographymass spectrum (GC-MS). A total of 156 volatile and semivolatile compounds were identified from 30 accessions of aromatic rice, including 32 alcohols, 25 acids, 25 ketones, 21 hydrocarbon, 18 esters, 16 aldehydes, 4 ethers, 5 amines, 2 phenols, 2 bases, and 8 miscellaneous compounds. By UPGMA/Neighbor-join tree analysis, the thirty accessions of aromatic rice could be classified into seven groups according to the major odor or aroma compounds. Group I included indica type of Basmati varieties. Group II and Group IV included japonica type introduced scented. Group III consisted only Hyangmibyeo1ho in domestic scented. Group V and Group VII included indica type of Basmati and non-Basmati varities. Group VI included four of domestic scented of seven accessions excepted Basmati6129, Basmati 6311, and Seratus Malam.

• Journal of Korean Society for Atmospheric Environment
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• v.25 no.5
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• pp.420-431
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• 2009

Characteristics and advantages of the thermal desorption-comprehensive two dimensional gas chromatography-time of flight mass spectrometry (TD-GCxGC-TOFMS) were discussed and the organic compound's analysis result was shown for the ambient $PM_{2.5}$ sample collected in Seoul, Korea. Over 10,000 individual organic compounds were separated from about $70{\mu}g$ of aerosols in a single procedure with no sample pre-treatment. Among them, around 300 compounds were identified and classified based on the mass fragmentation patterns and GCxGC retention times. Several aliphatic compounds groups such as alkanes, alkenes, cycloalkanes, alkanoic acids, and alkan-2-ones were identified as well as 72 PAH compounds including alkyl substituted compounds and 8 hopanes. In Seoul aerosol, numerous oxidized aromatic compounds including major components of secondary organic aerosols were observed. The inventory of organic compounds in $PM_{2.5}$ of Seoul, Korea suggested that organic aerosol were constituted by the compounds of primary source emission as well as the formation of secondary organic aerosols.

• Korean Journal of Microbiology
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• v.41 no.3
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• pp.201-207
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• 2005

A phenanthrene-degrading bacterium HS362, which is capable of using phenanthrene as a sole carbon and energy source, was isolated from oil contaminated soil. This strain is a gram negative, rod shaped organism that is most closely related to Sphingomonas paucimobilis based on biochemical tests, and belongs to the genus Sphingomonas based on fatty acids analysis. It exhibited more than $99.2{\%}$ nucleotide sequence similarity of 16S rDNA to that of Sphingomonas CF06. Thus, we named this strain as Sphingomonas sp. HS362. It degraded $98{\%}$ of phenanthrene after 10 days of incubation when phenanthrene was added at 500 ppm and $30{\%}$ even when phenanthrene was added at 3000 ppm. Sphingomonas sp. HS362 could also degrade low molecular weight PAHs(Polycyclic aromatic hydrocarbons) such as indole and naphthalene, but was unable to degrade high molecular weight PAHs such as pyrene and fluoranthene. The optimum temperature and pH for phenanthrene degradation were $30^{\circ}C$ and $4{\~}8$, respectively. Sphingomonas sp. HS362 could degrade phenanthrene effectively in the concentration range of NaCl of up to $1{\%}$. Its phenanhrene degrading ability was enhanced by preculture, suggesting the possibility of induction of phenanthrene degrading enzymes. Starch and surfactants such as SDS, Tween 85, and Triton X-100 were also able to enhance phenanthrene degradation by Sphingomonas sp. HS362. It carries five plasmids and one of them, plasmid p4, is considered to be involved in the degradation of phenanthrene according to the plasmid curing experiment by growing at $42^{\circ}C$.

• Journal of Soil and Groundwater Environment
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• v.20 no.7
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• pp.70-79
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• 2015

A sample of soil humic acid (HA) was divided by ultrafiltration (UF) into five fractions of different molecular size (UF₁: > 300, UF₂: 100~300, UF₃: 30~100, UF₄: 10~30, UF₅: 1~10 kilodaltons). Apparent average molecular weight (M_w) of the HA fractions were measured using high performance size exclusion chromatography (HPSEC), and the chemical and structural properties of the five HA fractions were characterized by elemental compositions (H/C, O/C and w ((2O + 3NH)/ C)) and ultraviolet-visible absorption ratios (SUVA, A_4/6). The organic carbon normalized-sorption coefficients (Koc) for the binding of phenanthrene to the HA fractions were determined by fluorescence quenching and relationship between the sorption coefficients and structural characteristics of the HA fractions were investigated. The elemental analysis and UV-vis spectral data indicated that the HA fractions with higher molecular weights have grater aliphatic character and lower contents of oxygen, while the HA fractions with lower molecular size have greater aromatic character and molecular polarity that correspond to greater SUVA and internal oxidation values (w). The log Koc values (L/kg C) were gradual increased from 4.45 for UF₅ to 4.87 for UF1. The correlation study between the structural descriptors of the HA fractions and log Koc values of phenanthrene show that the magnitude of Koc values positively correlated with $M_w$ and H/C, while negatively correlated with the independent descriptors of the O/C, w, SUVA and A_4/6.

• Bulletin of the Korean Chemical Society
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• v.33 no.12
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• pp.4180-4184
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• 2012

The target compounds 6-11a-e were synthesized by condensing 4-amino-5-aryl-3H-1,2,4-triazole-3-thiones 5a-f with various aromatic carboxylic acids in the presence of phosphorous oxychloride. The structures of newly synthesized compounds were characterized by IR, $^1H$ NMR, $^{13}C$ NMR, elemental analysis and mass spectrometric studies. All the synthesized compounds were screened for their antibacterial activity. Almost all the tested compounds were potent against four different strains of bacteria when compared with that of reference drug ciprofloxacin. Compounds 6c, 6e, 8d, 9b, 9e, 11a and 11b showed nearly equal or lower MIC values than standard drug, against all four tested bacterial strains but rest of the compounds showed excellent antibacterial activities.