• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.178.1-178.1
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• 2011

DME is generally expected to be used as a promising clean alternative fuel to diesel fuel. DME is not natural product but a synthetic product that is produced either through the dehydration of methanol or a direct synthetic from syngas. As DME has no carbon-carbon bond in its molecular structure and is an oxygenate fuel, it's combustion essentially generates no soot. DME has such cetane number of 55~60 that it can be used as a diesel engine fuel. However, DME has low lubricity but a proven method to solve the poor lubricity is by adding lubricity improver. Therefore, the aim of this study is to develop lubricity improver of DME as a transport fuel in Korea. In this study, we investigated a possibility of fatty acid ester compounds as a candidate to improve DME lubricity as compared with current lubricity improver of diesel. We also evaluated quality characteristics, storage stability of DME with lubricity additives.

• Journal of Microbiology and Biotechnology
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• 제18권6호
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• pp.1005-1010
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• 2008

The genus Burkholderia consists of extremely versatile bacteria that occupy diverse niches and are commonly encountered in the rhizosphere of crop plants. In this study, we characterized three plant growth promoting strains assigned as Burkholderia sp. using biochemical and molecular characterization. The Burkholderia spp. strains CBMB40, CBPB-HIM, and CBPB-HOD were characterized using biochemical tests, BIOLOG carbon substrate utilization, fatty acid methyl ester analysis, analysis of recA gene sequences, and DNA-DNA hybridization. The results from these studies indicated that the strains CBMB40, CBPB-HIM, and CBPB-HOD can be assigned under Burkholderia vietnamiensis, Burkholderia ubonensis, and Burkholderia pyrrocinia, respectively.

• Tribology and Lubricants
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• 제29권6호
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• pp.392-396
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• 2013

Biodiesel fuels contain unsaturated fatty acid ester, which can easily oxidize, especially when exposed to ultraviolet light. The products formed by this oxidation give rise to sediment or gum formation. As a result, the fuel can contribute to the corrosion and plugging of the filter pump. Antioxidants have been used in an effort to stabilize biodiesels, but there is still a need for a biodiesel composition with improved oxidation stability. In general, good fuel compositions should provide synergistic combinations of a biodiesel and antioxidants. Our work involved the synthesis of antioxidants to improve the oxidative stability of biodiesel fuel.

• Tribology and Lubricants
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• 제29권2호
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• pp.117-123
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• 2013

Dimethyl ether (DME) has a high cetane number that is suitable for diesel fuel. DME does not contain sulfur or nitrogen, and is an oxygenated fuel so it produces no particulate matter when combusted and is environmentally friendly. DME fuel for diesel engines show excellent material properties such as a lower volumetric heating value, lower boiling point, lower lubricity, and stronger solvent effect than light oil. This study experimentally examined a lubricity improver (LI) for dimethyl ether. A diesel LI based on biodiesel and fatty acid methyl ester was tested among DME LI candidates. The long-term storage stability and physical properties of the optimum LI for DME were determined.

• 한국식품영양학회지
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• 제2권2호
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• pp.65-71
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• 1989

Deer horn has been used in oriental medicine and folk remedy. It has had much effects on 'health and tonic efficacy' But this word, 'health and tonic efficacy', is very obscure in modern sense This report attempts to investigate their scientific and objective effects among many papers. The biochemical components of antler are composed of pentoses, hexoses, acid mucopolysaccharides, free and ester fatty acids, glycolipids, phospholipids, prostaglandins, sterols, protein and peptides, free amino acids, minerals, hormones etc. Deer horn extract especially increases body weight gain and feed efficiency, and it stimulates the ability of spermatogenesis of animal. However, a few papers have reported concerning the toxicity and side effects of antler.

• Journal of Nutrition and Health
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• 제24권6호
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• pp.485-495
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• 1991

Using isolated perfused livers obtained from rats that have been fed saturated and unsatu-rated fatty acid diets the rates of hepatic microsomal oxidation of 7-ethoxycoumarin(EC) to 7-hydroxycoumarin(HC) and the rates of subsequent conjugation of the produced HC to its glucuronide and sulfate esters have been determined. Prior to preparing the isolated perfused livers. rats were fed either fat free diet 10% beef tallow diet or 10% corn oil diet for 3 weeks. The rates of oxidation from EC to HC and also of the subsequent glucuronidation of HC were higher in the corn oil diet group than those found for the fat free and beef tallow diet groups. When the concentrations of infusing EC were increased stepwise there was a dose-dependnet increase for the release of the glucuronide form of HC metabolites at the expense of the sulfate ester form. This dose dependant shift observed for the corn oil group was more significnat than those found for other groups. These results indicate that corn oil feeding has produced enhancement in the rates of hepatic microsomal drug oxidation and glucuronide conjugation the reactions catalyzed by enzymes embedded in the hepatic microsomal membranes.

• 한국식품영양과학회지
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• 제28권4호
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• pp.816-821
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• 1999

Cholesterol esterase(pCEH, pancreas cholesterol ester hydrolase, E.C.3.1.1.13) which is secreted from pancreas has been known as an important lipase for cholesterol uptake. cholesteryl acyl esters from a diet must be hydrolyzed to free cholesterol and fatty acid by cholesterol esterase before the absorption in small intestine. For the development of inhibitory substances from natural source, we screened many extracts of oriental herbs for the inhibition of cholesterol esterase in vitro. The ethanol extract of Ephedra herba showed strong inhibitory activity. Solvent fractionation and silica gel column chromatography with the extract lead to the purification of the inhibitory principle in Ephedra herba. Crystallized inhibitor was identified as ( ) ephedrine by using UV, FT IR, 1H NMR, 13C NMR and GC/Mass. These results suggest that ( ) ephedrine can be used as a potential lead compound for the development of inhibitor for cholesterol uptake by cholesterol esterase inhibition.

• 한국식품영양과학회지
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• 제13권2호
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• pp.169-174
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• 1984

해바라기 화분립이 mouse의 간장에서 cholesterol 대사에 어떤 영향을 미치는가를 조사하기 위해서 해바라기 화분립으로부터 추출한 지질을 column chromatography, thin-layer chromatography 및 gas-liquid chromatography를 이용해서 분석했다. 또한 mouse에 화분립을 투여하였을 때 간장에서의 cholesterol치에 미치는 영향에 대해서도 조사하였다. 1. 화분립의 지질은 neutral lipid 84.10%, glycolipid 10.50%, phospholipid 5.40%를 함유했다. 2. 중성지방질의 조성은 triglyceride가 71.20%로 가장 많고, sterol ester, diglyceride, monoglyceride, free fatty acid, sterol의 순이다. 3. neutral lipid, glycolipid, phospholip의 주요지방산은 linoleic acid 28.48${\sim}$33.70%, palmitic acid 12.90${\sim}$47.50%, oleic acid 11.20${\sim}$12.20% 이다. 그러나 phospholipid는 다른 지질보다 palmitic acid를 더 많이 함유하고 있다. 4. 해바라기 화분립 투여 mouse의 체중은 대조군 보다 현저하게 증가했다. 5. 화분립을 투여한 mouse의 간장지질대사가 대조군보다 활발함을 알 수 있었다. 6. 화분립 투여 mouse의 간 cholesterol치가 초기에는 증가했으나, 말기에는 대조군과 비슷한 수준으로 감소했다.

• Parasites, Hosts and Diseases
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• 제54권2호
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• pp.139-145
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• 2016

Toxoplasmosis is a serious disease caused by Toxoplasma gondii, one of the most widespread parasites in the world. Lipid metabolism is important in the intracellular stage of T. gondii. Stearoyl-CoA desaturase (SCD), a key enzyme for the synthesis of unsaturated fatty acid is predicted to exist in T. gondii. Sterculic acid has been shown to specifically inhibit SCD activity. Here, we examined whether sterculic acid and its methyl ester analogues exhibit anti-T. gondii effects in vitro. T. gondii-infected Vero cells were disintegrated at 36 hr because of the propagation and egress of intracellular tachyzoites. All test compounds inhibited tachyzoite propagation and egress, reducing the number of ruptured Vero cells by the parasites. Sterculic acid and the methyl esters also inhibited replication of intracellular tachyzoites in HFF cells. Among the test compounds, sterculic acid showed the most potent activity against T. gondii, with an $EC_{50}$ value of $36.2{\mu}M$, compared with $EC_{50}$ values of $248-428{\mu}M$ for the methyl esters. Our study demonstrated that sterculic acid and its analogues are effective in inhibition of T. gondii growth in vitro, suggesting that these compounds or analogues targeting SCD could be effective agents for the treatment of toxoplasmosis.

• 생약학회지
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• 제6권1호
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• pp.15-21
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• 1975

인삼(人蔘)의 ether 추출물(抽出物)로부터 유리(遊離) 지방산(脂肪酸)을 분리(分離)하고 이것을 diazomethane으로 처리하여 methyl ester를 만든 다음 초산수은 및 column chromatography를 이용(利用)하여 포화(飽和) 지방산(脂肪酸)과 불포화(不飽和) 지방산(脂肪酸)으로 분리(分離)하였다. 분리(分離)된 지방산(脂肪酸)을 G. L. C.에 의하여 분석(分析)하여 다음과 같은 결론(結論)을 얻었다. 1) 한국산(韓國産) 인삼(人蔘) 6년생근중(年生根中)에는 유리(遊離) 지방산(脂肪酸)이 0.28% 함유(含有)되어 있다. 2) 인삼중(人蔘中)에서 24 종류(種類)의 유리(遊離) 지방산(脂肪酸)이 발견(發見)되었으며 그 중(中) 22 종류(種類)는 G. L. C.에 의(依)하여 확인(確認)되었으나, 나머지 2 종류(種類)는 G. L. C. data 만 가지고는 확인(確認)할 수 없었다. 미확인(未確認)의 두 지방산(脂肪酸)은 그 양(量)이 다량(多量)이었으며 천연(天然)에 흔히 존재(存在)하지 않는 unusual fatty acids 라고 사료(思料)된다. 3) $L_{EE}$ 등(等)은 인삼중(人蔘中)에 n18:3이 존재(存在)한다고 보고(報告)한 바 있으나 본실험(本實驗)에서는 n18:3의 존재(存在)를 확인(確認)할 수 없었으며 그 대신(代身) peak XVI이 n18:2와 n18:3의 사이에서 나타남을 보여준다. peak XVI은 미확인(未確認) 지방산(脂肪酸)이다.