• 대한화학회지
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• 제26권5호
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• pp.291-295
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• 1982

Li염이 아미드와 상호작용할 때 카르보닐기와 알킬기의 $^{13}C$chemical shift는 낮은 양쪽으로 이동하였으며, $Li^+$이온이 카르보닐기에 직접 결합함을 보였다. $^{13}C$ chemical shift의 크기는 아미드에 붙어있는 알킬기의 크기뿐만 아니라 음이온과의 상호작용에 의해서 지배됨을 알았다. 전하밀도가 큰 $Cl^-$이온이 $LiClO_4^-$이온보다 큰 음이온 효과를 나타냄을 보인다.

• 한국식품영양학회지
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• 제13권4호
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• pp.360-364
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• 2000

유지에 존재하는 linoleic acid의 전기화학적 산화/환원으로부터 속도론적 인자를 예측하고, 시간 변화에 대한 산패 정도를 조사하였다. Linoleic acid의 전기 화학적 산화환원 반응은 비가역적이고, 확산지배적으로 진행됨을 알 수 있고, 주사속도에 따른 결과로부터 확산계수 $D_{o}$ 는 2.61$\times$$10^{-6}$이고, 속도상수 $K^{o}$ 는 9.79$\times$$10^{-11}$로 주어짐을 예측하였다. 또한 linoleic acid의 산화반응 영역과 환원반응 영역에서 작업전극의 선택도가 달라짐을 볼 수 있다. 대기중 방치시간에 따른 시험 결과 방치한 지 4일을 전후로 산화 peak가 최대값으로 주어졌다. 특정 Peak에서 일정전위 전기분해 한 후 전기분해 생성물을 분석한 결과 carbonyl group이 생성됨을 예측할 수 있었다.

• Food Science and Biotechnology
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• 제17권6호
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• pp.1341-1344
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• 2008

The present study was conducted to investigate the effects of flowers ethanol extract of Elsholtzia splendens (ESE) on the antioxidant defence system in mice with 7,12-dimethylbenz(a)anthracene (DMBA)-induced oxidative stress. The ESE was pre-administered orally to 2 groups of mice at 10 and 50mg/kg body weight (BW) for 5 weeks. Subsequently, mice with pretreatment of ESE received DMBA intragastrically at a dose of 34 mg/kg BW twice a week for 2 weeks. In DMBA alone group, biomarkers of oxidative stress (TBARS value, carbonyl content, and serum 8-OH-dG) were significantly increased. Also, the antioxidant enzymes were down-regulated. ESE significantly restored the TBARS value and carbonyl content at both doses, while a decrease in the elevated serum 8-OH-dG content was observed only at the higher dose. The DMBA-induced decreases in catalase and superoxide dismutase (SOD) activities were restored to nearly control levels by ESE. Glutathione peroxidase (GSH-px) and glutathione reductase (GR) activities, as well as the reduced glutathione (GSH)/oxidized GSH (GSSG) ratio, were significantly affected by ESE at the higher dose. These results suggest that ESE possesses antioxidant activity, which plays a protective role against DMBA-induced oxidative stress.

• 한국토양비료학회지
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• 제20권3호
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• pp.251-259
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• 1987

7종(種)의 식물성(植物性) 유기물질(有機物質)을 부숙(腐熟)시키면서 경시적(經時的)으로 시료(試料)를 채취(採取)한 후 부식산(腐植酸)을 추출정제(抽出精製)하여 IR Spectrum의 특성(特性)을 규명(糾明)하였다. 이 Spectrum과 분석(分析)을 행해 Total acidity, Total hydroxyls, Carboxyl groups, Phenolic hydroxyls, Alcoholic hydroxyls, Carbonyl groups 그리고 Quinones 등(等)의 산소함유작용기(酸素含有作用基)의 함량(含量)을 정량(定量)하여 얻은 결과(結果)는 다음과 같다. 1. IR Spectrum을 크게 세 가지 유형(類型)으로 분류(分類)하였다. 볏짚, 보리짚 및 호밀짚등(等)의 곡물작물 재료의 부식산(腐植酸)을 Type I으로, 산야초(山野草)의 부식산(腐植酸)을 Type II, 그리고 활엽수(闊葉樹)잎과 침엽수(針葉樹)의 잎에서 추출(抽出)한 부식산(腐植酸)을 Type III으로 분류(分類)하였다. 2. 동일(同一)한 식물성(植物性) 유기물질(有機物質)에서 추출(抽出)한 부식산(腐植酸)은 부숙기간(腐熟期間)에 관계(關係)없이 IR Spectrum에는 차이(差異)가 없었다. 3. IR Spectrum에서 $3430cm^{-1}$의 흡수대(吸收帶)는 Hydroxyl groups 이며 이 중 phenolic hydroxyl groups가 대부분(大部分)을 구성(構成)하고 있었다. 4. Phenolic hydroxyl groups와 Total acidity 간(間)에, Carboxyl groups와 Total hydroxyl groups 간(間)에 그리고 Alcoholic hydroxyl groups와 Total hydroxyl groups 간(間)에는 밀접(密接) 관계(關係)가 있었다. 5. Carbonyl groups와 Quinones의 흡수대(吸收帶)가 중복(重復)되는 까닭으로 인(因)해 이 두 작용기(作用基)는 IR Spectrum으로는 구별(區別)하기 곤란(困難)하였다. 6. IR Spectrum에서 $995{\sim}1000cm^{-1}$의 흡수대(吸收帶)는 부식산(腐植酸)의 구성성분중(構成成分中) Non-aromatic cyclic hydrocarbon 화합물(化合物)임이 예증(例證)되었다.

• 약학회지
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• 제20권3호
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• pp.130-137
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• 1976

Specific association phenomena of riboflayin-2',3',4',5',- tetraacetate and salicylic acid derivatives, such as salicylic acid, aspirin and salicylamide have been measured by infrared and fluorescence spectroscopy. Salicylic acid and riboflavin tetraacetate oxyl group of the former. Asprin and riboflavin tetraacetate form the 1:1 cyclic hydrogen bonded dimer by the same mode. Salicylamide froms the 1:1 cyclic hydrogen bonded dimer with riboflavin tetraacetate by using its amide group and carbonyl group. Salicylic acid derivatives are effective quenchers of the fluorescence of riboflavin tetraacetate. It is appeared that salifylamide is the strongest quencher among them. The quenching effect is attributed to the formation of association dimer.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 추계학술대회 논문집 전기설비전문위원
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• pp.203-206
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• 2008

To improve mean-life and reliability of power cable in this study, we have investigated chemical properties showing by changing the content of carbon black that is semiconductive additives for underground power transmission. Specimens were made of sheet form with the three of existing resins and the nine of specimens for measurement. Chemical properties of specimens was measured by FT-ATR (Fourier Transform Attenuated Total Reflectance). The condition of specimens was a solid sheet. We could observe functional group (C=O, carbonyl group) of specimens through FT-ATR. From these experimental result, the concentration of functional group (C=O) was high according to increasing the content of carbon black. We could know EEA was excellent more than other specimens from above experimental results.

• EDISON SW 활용 경진대회 논문집
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• 제4회(2015년)
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• pp.91-98
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• 2015

Formamide의 중성가수분해 mechanism은 QM/MM (quantum mecahnics/molecular mechanics) molecular dynamics simulations 및 CPMD과 같은 방법으로 연구되어왔다. 본 연구에서는. Umbrella sampling을 이용한 QM/MM-MD simulation을 사용하여 4가지 반응의 free energy surface를 도출해냈다. 전체적으로, 가장 선호되는 메커니즘은 two step으로 구성된 water assisted stepwise mechanism이었으며 모든 mechanism은 ab-initio calculation과 QM/MM-MD simulation이 수행되었다. water assisted stepwise mechanism을 살펴보면, 첫 번째 step에서 formamide의 carbonyl group이 hydrate되면서 gem-diol intermediate를 형성한다. 다음 step에서, intermediate의 hydroxyl group으로부터 amino group으로 water-assisted proton transfer이 일어난다. 두 반응 모두에서 물이 proton transfer를 직접적으로 도와주는 것을 관찰할 수 있었다. 특히, ab-initio calculation과는 다르게 QM/MM-MD에서는 gem-diol intermediate가 안정화되는 것으로 solvent effect를 잘 보여준다.

• 약학회지
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• 제28권2호
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• pp.101-127
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• 1984

The study of interaction between riboflavin derivatives and biologically active substances was reviewed. With combination of spectroscopic methods such as NMR, UV, Fluorescence and IR, informations about interaction mechanism including hydrogen bond formation, conformation of association complex, and association constant were obtained. 1. Riboflavin associated with adenine but not with other bases found in the nucleic acids. -CONHCO- group was included in the formation of hydrogen bond with adenine. 2. Riboflavin interacted with alcohol to make a 1 : 1 association complex through the 3N-imino and 2C-carbonyl group of the isoalloxazine ring and the hydroxyl group of the alcohols. 3. Riboflavin associated with salicylates to produce the cyclic hydrogen-bonded dimer. The strongest complex was formed with salicylic acid, a weaker one with aspirin, and an even weaker one with salicylamide. 4. Other bio-active substances, orotic acid and inhibitors such as phenol, trichloroacetic acid and indol also formed hydrogen bond with riboflavin. 5. Reduced riboflavin showed strong self-association to produce the cyclic hydrogen-bonded complex and it associated with adenine and with cytosine to form 1 : 3 complex.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 추계학술대회 논문집 전기물성,응용부문
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• pp.117-119
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• 2004

To improve mean-life and reliability of power cable in this study, we have investigated chemical properties showing by changing the content of carbon black that is semiconductive additives for underground power transmission. Specimens were made of sheet form with the three of existing resins and the nine of specimens for measurement. Chemical properties of specimens was measured by FT-ATR (Fourier Transform Attenuated Total Reflectance). The condition of specimens was a solid sheet. We could observe functional group (C=O, carbonyl group) of specimens through FT-ATR. From these experimental result, the concentration of functional group (C=O) was high according to increasing the content of carbon black. We could know EEA was excellent more than other specimens from above experimental results.

• Bulletin of the Korean Chemical Society
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• 제11권2호
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• pp.144-149
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• 1990

Conformational free energy calculations using an empirical potential function (ECEPP/2) and the hydration shell model were carried out on the sulfonylurea herbicides of bensulfuron methyl (Londax) and metsulfuron methyl (Ally). The conformational energy was minimized from starting conformations which included possible combinations of torsion angles in the molecule. The conformational entropy of each conformation was computed using a harmonic approximation. To understand the hydration effect on the conformation of the molecule in aqueous solution, the hydration free energy of each group was calculated and compared each other. It was found that the low-free-energy conformations of two molecules in aqueous solution prefer the overall folded structure, in which an interaction between the carbonyl group of ester in aryl ring and the first amido group of urea bridge plays an important role. From the analysis of total free energy, the hydration and conformational entropy are known to be essential in stabilizing low-free-energy conformations of Londax, whereas the conformational energy is proved to be a major contribution to the total free energy of low-free-energy conformations of Ally.