• 한국식품영양과학회지
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• 제16권2호
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• pp.136-146
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• 1987

도라지 뿌리의 향기성분을 규명하고자 도라지 뿌리의 향기성분을 상압 수증기 증류법으로 포집하여 중성, 염기성, 약산성 및 산성성분으로 분획하였다. Diazomethane 법으로 methyl ester 화한 산성부분을 위시한 4부분은 모세관 column을 장치한 GC 및 GC-MS로 분석하였으며 함황화합물은 FPD 검출기로써 검출하였다. 도라지 뿌리로부터 aliphatic hydrocarbons류 6종, aromatic hydrocarbons류 10종, terpene hydrocarbons류 2종 alcohol류 12종, terpene alcohol류 8종 aldehyde류 17종 terpene aldehyde류 3종 ketone류 5종 ester류 5종, furan류 3종, thiazole류 2종, lactone류 2종, sulfide류 2종, phenol류 2종, 산류 12종 및 기타 5종을 위시하여 총 103종의 향기성분이 동정되었다. Caboxylic acid를 제외한 향기성분은 대부분 중성부분에서 동정되었고, 관능검사의 결과에서도 중성부분이 도라지 뿌리의 향기를 재현하는데 필요불가결한 것으로 나타났다. 관능검사의 결과, 중성부분에서 동정된 1-hexanal, trans-2-hexenal, 1-hexanol, cis-3-hexenol, trans-2-hexenol, 1-octenen-3-ol 등은 도라지 뿌리의 풋냄새의 주성분인 것으로 생각된다.

• 분석과학
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• 제19권1호
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• pp.86-95
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• 2006

현재 가동 중인 생활폐기물 소각시설에서 배출되는 소각재의 수세처리에 의한 유기화학물질 용출특성을 확인하기 위해 GC/MSD로 정성 분석을 하였다. 바닥재 및 비산재에서 각각 44종 및 17종의 다양한 유기화합물질을 확인하였다. 이러한 정성분석은 각 피크의 질량스펙트럼에 대한 Library(NIST21, NIST107, WILEY229) 검색 후 일치도가 90% 이상인 유사지표(similarity index)에 의해 수행되었다. 바닥재는 Naphthalene 그리고 Phenanthrene인 2종의 다방향족화합물(Polycyclic Aromatic Hydrocarbons, PAHs)을 포함한 18종의 방향족화합물과 사슬모양의 탄화수소인 26종의 지방족화합물을 검출하였다. 비산재의 경우 잔류성유기오염물질(Persistent Organic Pollutants, POPs)인 헥사클로로벤젠(Hexachlorobenzene, HCB)을 포함한 10종의 방향족화합물과 7종의 지방족화합물을 정성적으로 확인하였다. 또한, 바닥재와 비산재의 용출액과 용출잔사의 용출특성을 비교분석한 결과, 바닥재에서는 Ethenylbenzene, Benzaldehyde, 1-Phenyl-ethanone 그리고 1,4-Benzenedicarboxylic acid dimethyl ester 등이, 비산재에서는 Naphthalene, Dodecane, 1,2,3,5-Tetrachlorobenzene, Tetradecane, Hexadecane 그리고 Pentachlorobenzene등의 유기화합물이 수층으로 용출되는 결과를 얻었다. 따라서 소각재 중 비산재 및 바닥재가 단순 매립될 경우 유기화합물에 의한 침출수 및 지하수, 토양 등 2차 오염이 발생할 것으로 추정되며, 이러한 2차 오염을 방지하기 위해서 소각재에 함유되어 있는 다양한 종류의 유기화학물질의 용출특성을 조사하여 이에 대한 효율적이고 적정한 관리가 이루어져야 할 것으로 판단된다.

• Archives of Pharmacal Research
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• 제7권1호
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• pp.1-9
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• 1984

Polyethylene glycol 20, 000 and 6, 000 were found to have an upper consolute temperature, called "cloud point", and the effects of various additives on the polythylene glycols were investigated in this study. Electrolytes lowered the cloud point in proportion to their concentrations through dehydration and electrostriction. It was found that anions played a more important role than cations and the effects of both the cations and the anions clearly followed the classical Hofmeister series. However, the Schultze Hardy rule holds for the effect of anions, and fails for the effect of cations. Salts of large polarizable anions such as iodide and thiocynate rather raised the cloud point, and their effects were ascribed to the fact that they break the water structure and weaken hydrophobic bonding of the polyxyethylene moiety. Nitrates of polyvalent cations also raised the cloud point. This was ascribed to the complex formation between the polyvalent cations and ether oxygens of the polyoxyethylenes. This explained the failure 'of the Schultz-Hardy rule for cations. Uncharged aromatic compounds drastically lowered the clound point, while aliphatic alcohols slightly lowered the cloud point, This result suggests that there might be some interaction between ether oxygens and aromatic nucleus.c nucleus.

• 분석과학
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• 제6권4호
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• pp.383-390
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• 1993

지방족 카르복실산류, 방향족화합물류 및 알킬벤젠류에 대하여 역상 HPLC에서의 용출예측 방법을 검토하였다. 용출 파라미터로서 분자 크기를 나타내는 Van der Waasls 부피와 log k'와의 상관성을 검토한 결과, 양호한 직선성을 얻을 수 있었다. 용리액의 조성을 변화시키면서 또는 분리컬럼 온도를 변화시키면서 지방족 카르복실산류, 방향족화합물류 및 알킬벤젠류에 대하여 검토한 결과, acetonitrile이 log k'와 Van der Waals 부피와의 상관성이 가장 좋았다. 본 방법을 이용하여 역상 HPLC system에서 Van der Waasls 부피가 40~250 사이의 유기화합물들의 용출을 예측할 수 있었다. 각 용매의 용출력 세기는 methanol

• 한국환경농학회지
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• 제13권2호
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• pp.191-198
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• 1994

유기티탄 화합물들은 카르보닐 화합물들과의 첨가반응에서 알킬리튬이나 Grignard시약 같은 고전적인 유기금속화합물에 비하여 화학적, 입체화학적 선택성이 뛰어남은 이미 잘 알려져 있다. 하지만 탄소-탄소 결합에 이용된 유기티탄 화합물의 유기잔기는 방향족 중 일부와 aliphatic 중 methyl, allyl기 등에 한정되었다. 본 실험에서는 방향족 중 thiophene의 티탄화합물인 2-thiophenyl triisopropoxytitanium을 최초로 합성하고, 이것의 카르보닐 화합물과의 반응성을 실험하였다. 이 화합물은 알데히드와 케톤에 높은 수율(평균수율 94% 이상)로 첨가반응하고, 특히 알데히드와 케톤 경쟁반응에서 알데히드에만 그리고 케톤과 에스테르 작용기 사이에서는 케톤에만 화학 선택적으로 첨가 반응하였다. 그러므로 알데히드와 케톤기가 동시에 존재하는 화합물에서 케톤기를 보호시키지 않고 thiophene기를 직접 알데히드에 첨가할 수 있고, 케톤과 에스테르작용기가 있는 화합물에서는 케톤에 직접 첨가할 수 있는 새로운 방법이 개발되었다고 하겠다.

• Journal of Microbiology and Biotechnology
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• 제30권1호
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• pp.146-154
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• 2020

With the advantages of biocatalytic method, enzymes have been excavated for the synthesis of chiral amino acids by the reductive amination of ketones, offering a promising way of producing pharmaceutical intermediates. In this work, a robust phenylalanine dehydrogenase (PheDH) with wide substrate spectrum and high catalytic efficiency was constructed through rational design and active-site-targeted, site-specific mutagenesis by using the parent enzyme from Bacillus halodurans. Active sites with bonding substrate and amino acid residues surrounding the substrate binding pocket, 49L-50G-51G, 74M,77K, 122G-123T-124D-125M, 275N, 305L and 308V of the PheDH, were identified. Noticeably, the new mutant PheDH (E113D-N276L) showed approximately 6.06-fold increment of k_cat/Km in the oxidative deamination and more than 1.58-fold in the reductive amination compared to that of the wide type. Meanwhile, the PheDHs exhibit high capacity of accepting benzylic and aliphatic ketone substrates. The broad specificity, high catalytic efficiency and selectivity, along with excellent thermal stability, render these broad-spectrum enzymes ideal targets for further development with potential diagnostic reagent and pharmaceutical compounds applications.

• Journal of Astronomy and Space Sciences
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• 제15권1호
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• pp.163-174
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• 1998

To study the origin of organic matter in meteorite, terrestrial rocks which contain or-ganic compounds similar to the ones found in carbonaceous chondrites are studied and compared with Muchison meteorite. Hydrocarbon molecules were extracted by benzene and methanol from bituminous coal and oil shale and the extracts were partitioned into aliphatic, aromatic, and polar fractions by silica gel column chromatography. Carbon isotopic ratios in each fractions were analysed by GC-C-IRMS. Molec-ular compound identifications were carried by GC-MS Engine. Bituminous coal and oil shale show the organic compound composition similar to that of meteorite. Oil shale has a wide range of ${\delta}^{13}C,-20.1%_0~-54.4%_0$ compared to bituminous coal, $-25.2%_0~34.3%_0$. Delta values of several molecular compounds in two terrestrial samples are different. They show several distinct distributions in isotopic ratios compared to those of meteorite; Murchison meteorite has a range of ${\delta}^13C\;from\;-13%_0\;to\;+30%_0$. These results provide interpretation for the source and the formation condition of each rock, in particular alteration and migration processes of organic matter. Especially, they show an important clue whether some hydrocarbon molecules observed in meteorite are indigenous or not.

• 한국환경과학회지
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• 제14권6호
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• pp.597-603
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• 2005

In this study, we try to determine the distributive property in southwest coastal waters, such as K wang-yang bay, Ka-mak bay, Yeo-ja bay, Wan-do, Hea-nam, Young-gwang, and Mok-po, using simultaneous analytical method of 310 chemicals. The results were detected tens of the organic pollutants in sampling sites, and the major chemicals detected were CH type chemicals such as aliphatic, polycyclic compounds and were CHN(O) type chemicals such as aromatic amines, nitro compounds, In particular, pesticides were mainly detected in summer, phenols and phthalate esters were not seasonal effect. Also, a number of aromatic chemicals were detected in Kwang-yang bay, From the results of this study, we confirmed that it is mainly contaminated in summer and the pesticide chemicals are the major pollutants in southwest coastal waters.

• 분석과학
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• 제30권6호
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• pp.329-337
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• 2017

A major concern regarding most auto-repair shops in residential areas is the emission of odorous volatile organic compounds (VOCs) into the local atmosphere, especially during painting operations. VOCs contribute to poor local air quality and are responsible for the perceived odor and discomfort experienced by local residents. Sixteen major VOCs (6 aromatic hydrocarbons and 10 aliphatic carbonyl compounds) were selected as potential target compounds. The site was an auto-repair shop located in a central region of Seoul, South Korea, where the air quality of the site has been a subject of residents' complaints. The sampling points were as follows: 1) in the painting booth with new (NB) or old (OB) removal system, (2) in the exhaust duct after new (ND) or old (OD) odor removal filter, and (3) 2 m below the discharge vent (4 m above the ground) (outdoor air, OA). Each sample was coded: (1) before painting (BP), (2) during painting (DP), and (3) after painting (AP). The toluene level in the duct with the new removal filter during painting (ND-DP) was 1.5 ppm (v/v), while it was 3.8 ppm (v/v) in the right duct with an old removal filter during painting (OD-DP). Accordingly, the effect of filter replacement was reflected by differences in VOC levels. Therefore, accurate monitoring of odorous VOCs is an important step to reduce odor nuisance from local sources.

• Applied Biological Chemistry
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• 제25권3호
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• pp.161-165
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• 1982

홍삼갈변(紅蔘褐變)의 적합(適合)한 촉진방법(促進方法)을 구명(究明)하기 위하여 인삼(人蔘)에 당(糖), amino산(酸) 및 무기질소화합물(無機窒素化合物)을 처리(處理)한 결과(結果) 당류중(糖類中)에서는 maltose와 glucose가 가장 강(强)한 갈변축진작용(褐變促進作用)을 나타내었다. amino산(酸)은 basic amino acid인 lysine, histidine, arginine이 가장 크게 촉진(促進)했으며 당(糖)과 amino산(酸) 혼합처리(混合處理)에서는 glucose와 glutamic acid 혼합처리구(混合處理區)가 가장 크게 촉진(促進)되었다. Glucose농도별(濃度別) 처리시(處理時)의 갈변촉진효과(褐變促進?果)는 glucose농도(濃度)가 증가(增加)함에 따라 갈변(褐變)이 촉진(促進)되었으며 무기질소화합물중(無機窒素化合物中)에서는 $urea>(NH_4)_2HCO_3>CH_3COONH_4$등의 순(順)으로 갈변(褐變)이 촉진(促進)되었다.