• Applied Biological Chemistry
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• 제27권1호
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• pp.14-20
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• 1984

우리 나라에서 비교적 생산량이 많은 사과과실 3품종(Fuji, 홍옥, 국광)을 대상으로 향기성분을 분리 및 동정하고, 또한 성숙시기별로 향기성분의 함량변화를 측정하였다. 향기성분은 30종 이상 분리되었고 그 중 ester 23종, alcohol 9종 및 aldehyde 2종을 동정하였다. 성숙중 향기성분의 종류와 함량은 증가하였으며 1-butanol, isobutyl butyrate, 2-pentanol, ethyl valerate 및 hexanal 등의 함량이 많았다.

• Bulletin of the Korean Chemical Society
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• 제34권12호
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• pp.3817-3824
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• 2013

Various separation modes in HPLC, such as anion exchange (AE), reversed-phase (RP), and affinity (AF) chromatography were examined for the separation of selenium species in human blood serum and urine. While RP- and AE-HPLC were mainly used for the separation of small molecular selenium species, double column AF-HPLC achieved the separation of selenoproteins in blood serum efficiently. Further, the effluent of AF-HPLC was enzymatically hydrolyzed and then analyzed with RP HPLC for selenoamino acid study. The versatility of the hybrid technique makes the in-depth study of selenium species possible. For quantification, post column isotope dilution (ID) with $^{78}Se$ spike was performed. ORC ICP/MS (octapole reaction cell inductively coupled plasma/mass spectrometry) was used with 4 mL $min^{-1}$ Hydrogen as reaction gas. In urine sample, inorganic selenium and SeCys were identified. In blood serum, selenoproteins GPx, SelP and SeAlb were detected and quantified. The concentration for GPx, SelP and SeAlb was $22.8{\pm}3.4\;ng\;g^{-1}$, $45.2{\pm}1.7\;ng\;g^{-1}$, and $16.1{\pm}2.2\;ng\;g^{-1}$, respectively when $^{80}Se/^{78}Se$ was used. The sum of these selenoproteins ($84.1{\pm}4.4\;ng\;g^{-1}$) agrees well with the total selenium concentration measured with the ID method of $87.0{\pm}3.0\;ng\;g^{-1}$. Enzymatic hydrolysis of each selenium proteins revealed that SeCys is the major amino acid for all three proteins and SeMet is contained in SeAlb only.

• 미생물학회지
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• 제53권3호
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• pp.193-199
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• 2017

This study was aimed to evaluate the antimicrobial activity of Penicillium purpurogenum ED76 on several clinically important microorganisms. The endophytic fungus P. purpurogenum ED76 was previously isolated from Swietenia macrophylla leaf. The antimicrobial efficacy of P. purpurogenum ED76 dichloromethane extract was determined via disc diffusion and broth microdilution assay. A kill curve study was conducted and the morphology of extract treated bacterial cells were viewed under scanning electron microscope. The dichloromethane extract showed significant inhibitory activity on 4 test bacteria and 2 test yeasts. The minimal inhibitory concentration of the extract ranged from 125 to $1,000{\mu}g/ml$, which indicates the different susceptibility levels of the test microorganisms to the fungal extract. The kill curve study has revealed a concentration-dependent inhibition for all test microorganisms. With the increase of the extract concentration, the microbial growth was significantly reduced. The scanning electron micrograph of dichloromethane extract-treated Staphylococcus aureus cells showed the total damage of the cells. The cell wall invagination of the bacterial cells also indicates the loss of cellular materials and metabolic activity. The gas chromatography mass spectrometry analysis of the extract also showed that the major compound was stigmasterol, which constitutes 45.30% of the total area. The dichloromethane extract of P. purpurogenum ED76 exhibited significant inhibitory activity on several clinically important bacteria and yeasts. The study proposed a possible mode of action that the extract cause significant damage to the morphology of S. aureus cells.

• 한국환경보건학회지
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• 제40권2호
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• pp.147-156
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• 2014

Objectives: This study was carried out to examine whether the apparent photolysis with or without sensitizers [NaOH and humic acid (HA)] was prompted photodegradation of polychlorinated biphenyl (PCB) in aqueous solution. Methods: PCBs photodegradation occurred using fluorescence black lamps at ${\lambda}_{max}=300nm$. PCB congeners were exposed in 10 ppm HA or 0.05N NaOH solutions, to investigate the decreasing profile of PCB concentration with time. The PCBs were then analyzed by gas chromatography/mass spectrometry (GC-MS). Reductive degradation profile of PCB congeners in the presence of both sensitizers under oxygen-saturated protic conditions was described using the wind-rose diagrams. Results: Use of HA or NaOH decreased PCB concentration with time in the dark and on irradiation, indicating that photolysis underwent through reductive dechlorination through energy transfer and possibly with reactive oxygens. The dechlorination was marked by a chromatographic shift, observed in the GC-MS plots. Therefore it is logical to assume that increasing the dose of sensitizers would increase the photodegradation rates of PCBs. The half-lives of pentachloro-PCB (penta-3) in 0.05N NaOH and 10 ppm HA were estimated at about 47 hours and 39 hours, respectively, under the same experimental conditions of photolysis. It was found that the rate of photolysis of pentachloro-PCB in aqueous solution followed apparent first-order kinetics compared to other congeners. Conclusion: Photochemical degradation (using 328 nm UV light) of penta- and hexa-PCBs in HA or alkaline solution is a viable method for pretreatment method. The results are helpful for the further comprehension of the reaction mechanism for photolytic dechlorination of PCBs in aquatic system.

• 한국환경과학회지
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• 제14권1호
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• pp.23-32
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• 2005

Surface sediments (0$\~$4 cm) were sampled at 40 stations from Ulsan Bay and its adjacent areas of Korea, to evaluate the contamination by sewage-derived organic matters using fecal sterols. Some sterols were quantified by gas chromatography coupled to mass spectrometry (GC/MS). Total concentrations of eight sterols (co­prostanol, cholesterol, cholestanol, epicholestanol, epicoprostanol, ${\beta}-sitosterol,$ brassicasterol, and stigmasterol) in the sediments from Ulsan Bay and its vicinity varied from 929 to 23,444 ng/g dry weight. The most predom­inant sterols were cholesterol and coprostanol, accounting for $33\~72{\%}$ of total sterols. The concentration of coprostanol known as the indicator of human feces ranged from 141 to 8,257 ng/g dry weight. In particular, the coprostanol concentrations in the sediments from Jansaengpo Harbor and Taehwa River exceeded the value of 1,000 ng/g dry weight, suggesting that these areas could be considered as the hot-spot zones by municipal sewage contamination. Some molecular indices and multivariate data analysis were used to assess the origin of these sterols in the sediments. Results showed that the major routes of sewage contamination in Ulsan Bay and its vicinity were the input through Jansaengpo Harbor and Taehwa River.

• 한국환경과학회지
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• 제15권4호
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• pp.293-304
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• 2006

Sea water samples collected in August, 1994 from 20 stations in the Kwangyang Bay were analyzed by gas chromatography/mass spectrometry-selected ion monitoring (GC/MS-SIM) to investigate persistence and distribution pattern of four organophosphorus pesticides (DDVP, Diazinon, IBP, EDDP). Except for IBP, the contamination by DDVP, Diazinon, and EDDP in marine aquatic environment in Korea has not been reported previously. In this study, however, all these four pesticides were detected in all stations (except DDVP) and their concentrations were in ng/L level. The concentrations ranged from detection limit to 15.3ng/L for DDVP, 1.8-27.7ng/L for Diazinon, 7.3-63.5ng/L for IBP, and 22.2-1100.1ng/L for EDDP. It is noteworthy that the measured concentrations of IBP and EDDP in this study would be much lower than usual, since the use of IBP and EDDP was less than 50% of average annual consumption due to unusually dry and hot weather condition in the summer of 1994. It was very surprising to find that the highest concentrations of organophosphorus pesticides were observed at stations near Daesa Streamlet instead of Seomjin River, which has more point source of the pesticides. This result suggests that the small river discharge during heavy ram period in summer can give harmful effect on marine biota (both wild and aqua-cultured) with its organophosphorus pesticide residue, despite of their short residence time in aquatic environment. In order to protect the marine life properly from acute toxicity of the organophosphorus pesticides, it needs to be emphasized that monitoring the level of agricultural pesticides in river run-off should be done during active consumption period rather at regular intervals.

• 한국식품영양과학회지
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• 제18권2호
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• pp.205-210
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• 1989

Capillary column GLC 및 GCMS를 병용하는 분석방법을 이용하여 식물유 트리글리세리드 분자종과 산화안정성과의 관계를 밝히기 위해서, 규산 컬럼으로 분획한 대두유 트리글리세리드를 모델 시료로 하여 $60^{\circ}C$, 암소에서 저장하면서 산화에 따른 트리글리세리드 각 분자종의 산화안정성을 조사하였다. 대두유 트리글리세리드의 주요 분자종은 LLL(19.6%), OLL(17.4%), PLL(14.2%), OLO(10.2%) 및 PLO(9.4%)이었으며, 트리글리세리드 분자종의 산화안정성은 전반적으로 구성불포차지방산의 이중결합수가 적을 수록 증가하는 경향을 보였다. 그런데 트리글리세리드를 구성하는 불포화지방산들의 이중결합수가 같을 경우는 불포화도가 낮은 지방산이 결합되어 있는 분자종의 산화안정성이 높았고, 또 결합되어 있는 불포화지방산의 이중결합수 및 불포화도가 똑같은 경우에는 공존하고 있는 포화지방산의 acyl의 사슬길이가 짧은 분자종의 산화안정성이 높은 것으로 밝혀져, 식물유 트리글리세리드 분자종의 산화안정성에는 구성불포화지방산의 이중결합수와 불포화도 및 공존하고 있는 포화지방산의 acyl기의 사슬길이가 중요한 영향을 미치는 인자임을 알 수 있었다.

• Preventive Nutrition and Food Science
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• 제16권1호
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• pp.55-61
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• 2011

A survey aiming to find out the chemical and textural properties of commercial fermented soy bean curd called sufu was conducted. Sixteen brands of plain sufu produced in the Northern or the Southern part of China were collected and examined for their crude protein, crude fat, texture profiles, free amino acids, and free fatty acid contents. Twenty-one free amino acids were extracted and derivatized using a commercial kit followed by separation and analyzed by the gas chromatography-mass spectrometry (GC-MS). Similarly, ten free fatty acids were extracted using alumina, eluted, separated and analyzed. The content ranges of crude fat and protein were 22~36% and 31~38%, respectively. In texture profile analysis, ranges of the texture parameters were 131~493 g (hardness), 0.4~0.5 (cohesiveness), -137 to -50 gs (adhesiveness), 0.6~1 (springiness), 47~220 g (gumminess) and 32~177 g (chewiness). Twenty-one different free amino acids, especially alanine, glycine, $\alpha$-aminobutyric acid, valine, leucine, allo-isoleucine, aspartic acid, glutamic acid and lysine in large amount, as well as ten fatty acids in total, notably linoleic acid (9-octadecanoic acid), oleic acid (9,12-octadecadienoic acid), linolenic acid (9,12,15-octadecadienoic acid), hexadecanoic acid and octadecanoic acid were found. This information provides important quality reference ranges for product developers and manufacturers to optimize and produce the plain sufu.

• 한국지역사회생활과학회지
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• 제23권3호
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• pp.255-263
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• 2012

Polybrominated diphenyl ethers (PBDEs) are a group of brominated flame retardants (BFRs), which are used in a variety of consumer products. Several of those are produced in large quantities. Their chemical structure similarities to polychlorinated dibenzo-p-dioxins and polychlorinated biphenyls (PCBs), as well as their toxicity, has been studied. PBDEs are persistent and lipophilic, which results in their bioaccumulation in the fatty tissues of organisms and enrichment throughout food chains. In addition, a number of studies also reported high levels of PBDEs in animals and food resulting from the use of contaminated animal feed Public concern about PBDEs levels in animals and food has been raised. Feed contamination by toxic chemicals has been the cause of the contamination of poultry products. The purpose of this study was to evaluate PBDEs in pig feed to search the origin chase of POPs in pigs. Feed samples were obtained wheat from East Europe, corn from South America and America, soybean meal from Korea, America, South America and India and tallow from Korea. The preparation of samples was based on the EPA method 1614. Instrumental analysis was based on the use of high resolution gas chromatography coupled to high resolution mass spectrometry (HRGC/HRMS). Quantification was carried out by the isotopic dilution method. The analysis of ${\Sigma}PBDEs$ involved 22 PBDE congeners, including BDE-17, 28, 47, 49, 66, 71, 77, 85, 99, 100, 119, 126, 138, 153, 154, 156, 183, 184, 190, 191, 196 and 197.

• 한국지역사회생활과학회지
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• 제23권2호
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• pp.129-136
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• 2012

Dioxins are chemical substances that are not properly decomposed degradation under natural photochemical, biological and chemical conditions in the environment, and bio-accumulate through the food chain, so pose a risk of causing adverse effects to human health and the environment. Ninety seven percent of human exposure to dioxins comes through meat, fish, dairy consumption and so on. Pork is the largest proportion meat aspect of daily intake in the Korean food. Pigs are three times more than Cattle in terms of breeding population and production amount in the world, and the amount is increasing every year. Therefore, it is necessary to monitor the exposure level of dioxins in pig's body. Also, it is required to evaluate the presence of these chemical substances in the pig's feed grain such as corn, soybeans, and tallow. The purpose of this study was to evaluate PCDD/Fs in pig's feed to search the origin of PCDD/Fs. Feed samples obtained were wheat from East Europe, corn from South America and America, soybean meal from Korea, America, South America and India and tallow from Korea. The preparation of samples was based on the EPA method 1613. Instrumental analysis was based on the use of high resolution gas chromatography coupled to high resolution mass spectrometry (HRGC/HRMS). The concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and 1,2,3,7,8-pentachlorodibenzo-p-dioxin (PCDD), which are the most toxic potent dioxins, were not observed in any of the samples. However OCDD was detected in most of the samples. The TEQs in the feed samples were ranged from 0 pg TEQ/g to 0.09841 pg TEQ/g. Especially, the high level of TEQs was observed in the samples of wheat from East Europe and soybean meal from Korea.