• 한국연초학회지
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• 제6권2호
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• pp.97-116
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• 1984

Volatile aroma components were extracted from Korean burley tobacco (grades: heavy-1, heavy-5, thin-1, and thin-5) by using a vacuum steam distillation apparatus. Individual flavor components were identified by combination of Carbowax20M (used silica capillary gas chromatography and mass spectrometry. Out of the identified components, neophytadiene (43.6ppm), megastigna-4,6,8-trien-3-one (4isomers) (3.32-23.5 1ppm), ethanol (1.8ppm), and ethylacetate (4.7ppm) were contained less in burley heavy grade-5 tobacco than in heavy grade 1 ; neophytadiene (43.7pp), megastigma-4,6,8-triers-3-one (4 isomers) (1.09-3.03ppm), ethylacetate (7.9ppm), and ethanol (8.4ppm), were less in burley thin grade 5 tobacco than in thin grade 1 : nicotin (75.79ppm), and solanone (8.5ppm) were less in burley heavy grade 1 tobacco than in burley heavy grade 5: solanone (5.76ppm), geranylacetone (9.02ppm), phenylacetaldehyde (1.12ppm), $\beta$-phenylethylalcohol (1.93ppm), and dihydroactinidiolide (1.39ppm) were less in burley thin grade 1 than in burley thin grade 5. On the other hand, iso-valeraldehyde, n-valeraldehyde, dimethylpyrazine, and propionic acid were not identified in Korean burley tobacco, but in American burley tobacco.

• 분석과학
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• 제8권4호
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• pp.901-906
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• 1995

Studies on the chemical constituents from a Korean wild mushroom, Phellinus ribis, were carried out. A triterpenoid, two peroxysterols, and a chlorobenzene compound were isolated from the hexane soluble fraction of the methanol extract of dried fruiting bodies of the basidomycetes. Those compounds identifed were 3-hydroxy-20(29)-lupen-28-oic acid (betulinic acid), 5,8-epidioxyergosta-6,22-dien-3-ol(ergosterol peroxide), 5,8-epidioxyergosta-6,9(11),22-trien-3-ol (dehydroperoxyergosterol), and 1,2,4,5-tetrachloro-3,6-dimethoxybenzene. Structural studies were carried out on molecular species of a ceramide and cerebroside isolated from the chloroform soluble fraction of the methanol extract. For ceramide, the major component fatty acids were a-hydroxy fatty acid isomers of $C_{22:00}{\sim}C_{25:00};$ the predominant long-chain bases were trihydroxy sphinganine of $C_{17}{\sim}C_{18}$. The structure of a cerebroside containing mono-sugar was assumed that the long-chain base was $C_{19:2}$ sphingadienine; the major fatty acids were $C_{16}{\sim}C_{15}$ ${\alpha}$-hydroxy fatty acid isomers.

• Journal of Ginseng Research
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• 제10권2호
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• pp.200-208
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• 1986

It was attempted in this study to investigate the effect of ginseng saponin on several glycolytic enzymes of yeast cell and the following results were obtained. The amount of $CO_2$formed during the incubation of yeast cells in medium containing saponin fraction of Panax ginseng C.A. Meyer was greater than that of control cells and found that the $CO_2$ formation was greatest when the cells were grown in the medium containing 10$^{-3}$% of the saponin fraction, at which the uptake of inorganic phosphate and glucose consumption were also increased. Radioactivity study of several glycolytic intermediates of yeast cells cultured in the medium containing [U-$^{14}$C]-glucose showed that the radioactivity of fructose 6-phosphate of test cells was as much as 1.6times that of control group. On the other hand, the radioactivity of pyruvate of test cells was considerably decreased compared to control. Investigation of the effect of ginseng saponin on yeast hexokinase, phosphoglucose isomers, pyruvate kinase and perverted decarboxylase in vitro showed that the maximum activities of the above enzymes were observed when the concentration of ginseng saponin was 10-$^{-5}$% in the reaction mixture. It seemed that the ginseng saponin stimulated both glycolytic enzymes such as hexokinase, phosphoglucose isomers and perverted decarboxylase significantly.

• 대한화학회지
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• 제27권2호
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• pp.117-126
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• 1983

탄소-13 및 바나듐-51 핵자기공명분광법을 이용하여 아미노폴리카르본산-바나듐(v) 착물의 용액 내에서의 구조에 대해 연구하였다. 이 때 사용한 리간드는 ethylenediaminetetraacetic acid (EDTA), trans-cyclohexanediaminetetraacetic acid (CDTA), 1,2-propylenediaminetetraacetic acid (PDTA), ethylenediaminediacetic acid (EDDA), 2-hydroxyethylethylenediaminetriacetic acid (HEDTA), diethylenetriaminepentacetic acid (DPTA), nitrilotriacetic acid (NTA) 등이었다. 모든 리간드는 바나듐(Ⅴ)과 시스-VO2핵을 함유하는 정8면체 구조의 1:1 착물을 생성하였다. 바나듐(V)과 시스-$VO_2$ 핵을 함유하는 정8면체 구조의 1:1 착물을 생성하였다. 바나듐(V)에 대한 히드록시에틸기의 배위는 아세테이트기의 배위에 비해 덜 바람직함을 알 수 있었다. 그리고 EDDA 및 PDTA는 각각 2가지의 이성체착물들을 생성함을 알 수 있었다.

• 한국분무공학회지
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• 제21권3호
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• pp.144-154
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• 2016

This review will be concentrated on the spray characteristics of biobutanol and its blends fuels in internal combustion engines including compression ignition, spark ignition and gas turbine engines. Butanol can be produced by fermentation from sucrose-containing feedstocks, starchy materials and lignocellulosic biomass. Among four isomers of butanol, n-butanol and iso-butanol has been used in CI and SI engines. This is due to higher octane rating and lower water solubility of both butanol compared with other isomers. The researches on the spray characteristics of neat butanol can be classified into the application to CI and SI engines, particularly GDI engine. Two empirical correlations for the prediction of spray angle for butanol as a function of Reynolds number was newly suggested. However, the applicability for the suggested empirical correlation is not yet proved. The butanol blended fuels used for the investigation of spray characteristics includes butanol-biodiesel blend, butanol-gasoline blend, butano-jet A blend and butanol-other fuel blends. Three blends such as butanol/ethanol, butanol/heptane and butanol/heavy fuel oil blends are included in butanol-other fuel blends. Even though combustion and emission characteristics of butanol/diesel fuel blend in CI engines were broadly investigated, study on spray characteristics of butanol/diesel fuel blend could not be found in the literature. In addition, the more study on the spray characteristics of butanol /gasoline blend is required.

• 대한화학회지
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• 제55권6호
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• pp.940-951
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• 2011

Reaction of 1-methylpyrimidine-(1H,3H,5H)-2,4,6-trione (1-MBA 1) as an unsymmetrical barbituric acid with cyanogen bromide and various aldehydes in the presence of triethylamine and/or pyridine afforded diastereomeric mixtures of new class of heterocyclic stable 5-aryl-1,1'-dimethyl- and 5-aryl-3,1'-dimethyl-1H,1'H-spiro[furo[2,3-d]pyrimidine-6,5'-pyrimidine]2,2',4,4',6'(3H,3'H,5H)-pentaones which are dimeric forms of 1-methyl barbiturate at the range of $0^{\circ}C$ to room temperature. In the reaction of some aldehydes with 1-MBA and BrCN were afforded a mixture of diastereomers. Another two aldehydes such as 4-cyano- and 2-hydroxybenzaldehydes gave exclusively two diastereomers in which binded to the salt of triethylammonium hydrobromide by intermolecular H-bond in ratio of 1:1. 4-Hydroxybenzaldehyde and 2-pyridinecarbaldehyde gave exclusively one diastereomer under the same condition. Aldehydes possessing strong electron-donor were produced exclusively two geometric isomers of Knoevenagel adduct (E- and Z-isomers). The structures of compounds were deduced by $^1H$ NMR, $^{13}C$ NMR and FT-IR spectroscopy. Mechanism of the formation is discussed.

• 대한화학회지
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• 제34권1호
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• pp.44-50
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• 1990

페놀류의 구조 이성질체의 액체 크로마토그래피적 머무름거동을 이동상의 성질을 변화시켜 조사했다. 역상 액체 크로마토그래피에서 페놀류의 구조이성질체에 대한 머무름거동은 첨가한 용리액의 전해질에 영향을 받았다. 이 머무름거동은 Langmuir의 흡착등온선과 페놀이온과 전해질 이온으로 코우팅 된 정지상 사이의 이온교환과정으로 설명할 수 있다. 이 거동은 전해질의 농도에 따라 두 영역으로 나누어져서 반대이온효과가 나타나는 부분과 동종이온효과가 나타나는 부분으로 설명할 수 있다. 머무름값이 극대가 나타나는 것은 유기용매의 종류에는 관계없이 전해질의 종류와 농도에 따라 다르게 나타났다.

• 대한화학회지
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• 제34권1호
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• pp.76-84
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• 1990

키랄이동상 첨가법으로 단실아미노산의 광학이성질체들을 분리했다. 두 가지의 xylenyl-L-proline 이성질체를 합성하고 이것을 구리(Ⅱ)킬레이트로 만들어 이동상에 첨가하여 단실아미노산의 광학 이성질체를 분리했다. 이 아미노산에 대한 용리거동은 benzyl-L-proline의 구리착물을 사용했을 때와 유사했다. 이동상에서 유기용매의 조성, 완충용액의 농도 및 pH에 대한 효과도 조사 검토했다. 분리메카니즘은 리간드 교환반응의 시스-트란스 효과의 삼성분착물과 정지상간의 소수성 상호작용으로 설명할 수 있었다.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1988년도 학술대회지
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• pp.19-24
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• 1988

[ $L_{1210}$ ] 세포에 대하여 세포독성이 있는 두개의 새로운 polyyne을 인삼으로부터 분리하였는데 이들은 acetylpanaxydol과 panaxy-dolchlorhydrin이다. Panaxydol 유사체의 C-9 위치에 있는 epoxy group과 C-10 위치의 heptyl group 은 세포독성을 강화시켜준다. Panaxydol의 epoxy group 은 cis와 trans 이성체들간의 세포독성 차이는 없다. Panaxydol과 이들 이성체들에서 세포독성을 발휘하는 필수구조는 hept-l-en-4.6-diyn-3-ol이다.

• 한국막학회:학술대회논문집
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• 한국막학회 2003년도 The 4th Korea-Italy Workshop
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• pp.61-64
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• 2003

Optical resolution of a-amino acid (tryptophan and tyrosine) optical isomers was achieved by a pressure driven membrane separation process, using self-supporting crosslinked membranes base on polysaccharide with different swelling indices that ranged from 100 to 70%. The membranes prepared by casting and drying the polymer solution containing 5wt% acetic acid on an acryl plate followed by crosslinking with glutaraldehyde were characterized using such analytical methods as FTIR and swelling index measurements. On the way of separating the optical isomers, several experimental factors such as the concentration of the feed solutions, operating pressure and temperature, and degree of crosslinking of the membranes have been studied. When the chitosan membranes with 70% of swelling index were used , almost complete optical resolution was obtained; 97.92% of enantiomeric excess (ee %) and 2.26 g/$m^2$ㆍh of flux. The operating pressure and the concentration of feed solutions were respectively 1.0 kgf/$\textrm{cm}^2$ and 0.49 mmol/L.