• Journal of Microbiology and Biotechnology
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• v.15 no.6
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• pp.1183-1188
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• 2005

Several lipases of commercial grade were screened to catalyze the methanolysis of castor oil, and an immobilized Candida antarctica (Novozym 435) had the highest activity among the lipases tested. To enhance the yield of methyl ricinoleate, several reaction parameters were optimized. The optimum temperature was $50^{\circ}C$, and the original water content of lipase was sufficient to maintain the activity of lipase, and additional water supplied inhibited the methanolysis of castor oil. Because the lipase was deactivated by methanol, the reaction was tested by three-step addition of 1 molar equivalent of methanol to the oil. However, the oil was not completely converted to its methyl esters. The final reaction mixture using 3 molar equivalents of methanol to the oil consisted of $70\%$ methyl ricinoleate, $18\%$ monoricinoleate, $11\%$ diricinoleate, and trace triricinoleate at the equilibrium state. The yield of methyl ricinoleate was $97\%$ at 6 molar ratio of methanol to the oil with 300g of castor oil and 6g of immobilized Candida antarctica at $50^{\circ}C$ within 24 h.

• Korean Journal of Food Science and Technology
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• v.24 no.3
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• pp.247-250
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• 1992

Effects of free alkali and moisture on sucrose polyesters (SPE)-possible non calorie fat substitute-synthesis were investigated using a model system composed of sodium oleate, sucrose, potassium carbonate and methyl oleate. Trace amounts of free alkali in sodium oleate were found to interefere with SPE synthesis. When free alkali content in sodium oleate was varied gradually from 0% to 5%(w/w), the yield of SPE production was reduced from 92% to 45.5%. The moisture absorbed in sodium oleate, sucrose and potassium carbonate during storage also interefered with SPE synthesis. The yield (92%) of SPE production with dried ($105^{\circ}C$.6 hrs) reactants and catalysts was higher than that (89%) of SPE production with non-dried. Soybean oil fatty acid sodium soaps (FASS) not containing free alkali could be manufactured with slightly less than molar ratio of sodium hydroxide to soybean oil fatty acid methyl esters (FAME). Practically, 91.7% yield of soybean oil SPE production was outcomed by minimizing free alkali and moisture which were remaining in sucrose, potassium carbonate, soybean oil FASS and soybean oil FAME.

• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.717-726
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• 2017

The current allowable cross-contamination level of fatty acid methyl esters (FAME) in aviation turbine fuel (AVTUR) is 50 mg/kg, due to that the presence of FAME in AVTUR can significantly impact the fuel supply system and jet engine. It has been difficult to analyze the level of FAME in AVTUR, since it is consisted of a lot of hydrocarbons. In this study, thus, a new method using multi-dimensional GC-MS (MDGC-MS) was proposed in order to determine the FAME level in AVTUR effectively. Applying to MDGC-MS with Deans switching system enabled us to detect and quantify the FAME with low carbon numbers such as those derived from coconut oil and palm kernel oil. The matrix effect of MDGC-MS method, which could shift the FAME peaks to slightly longer retention times, was reduced by 20 times compared with that of 1-dimensional GC-MS reference method. This developed method could be suitable for qualitative and quantitative analyses to determine the contamination level of trace FAME in AVTUR.

• Archives of Pharmacal Research
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• v.26 no.3
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• pp.202-206
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• 2003

In this study, some aryl (3-methyl-benzofuran-2-yl) ketoximes and their ethers and esters were synthesised. The structure elucidation of the compounds was performed by IR, $^1H-NMR$, MASS spectroscopy and elemental analyses. Antifungal activities of the compounds were examined and moderate activity was obtained.

• Journal of the Korean Applied Science and Technology
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• v.18 no.4
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• pp.298-305
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• 2001

Emulsified transesterification of soybean oil into biodiesel was investigated using potassium hydroxide and sodium methoxide catalysts with methyl glucoside oleic polyester as a methanol-in-oil emulsifier. The transesterification reaction conditions were optimized to obtain high yields of fatty acid methyl esters of the quality defined by biodiesel standards. The developed process resulted in $95{\sim}96%$ of overall yield from soybean oil by alkali-catalyzed methanolysis at $45^{\circ}C$ of reaction temperature with 6:1 of methanol-to-oil molar ratio and 1(v/v)% methyl glucoside oleic polyester in the presense of 0.8wt% KOH and 1.2wt% $NaOCH_{3}$.

• Bulletin of the Korean Chemical Society
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• v.8 no.4
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• pp.313-318
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• 1987

The approximate rate and stoichiometry of the reaction of excess Thexylbromoborane-methyl sulfide, $ThxBHBr{\cdot}SMe_2,$ with selected organic compounds containing representative functional groups under standardized conditions (methylene chloride, $0^{\circ}C)$ were studied in order to characterize the reducing characteristics of the reagent for selective reductions. The selectivity of the reagent was also compared to the selectivity of thexylchloroborane-methyl sulfide. Thexylbromoborane appears to be a much milder and hence more selective reducing agent than thexylchloroborane. The reagent tolerates many organic functionalities. Thus, the reagent shows very little reactivity or no reactivity toward acid chlorides, esters, epoxides, amides, nitro compounds including simple olefins. However, this reagent can reduce aldehydes, ketones, carboxylic acids, nitriles, and sulfoxides. Especially the reagent reduces carboxylic acids including ${\alpha},{\beta}$ -unsaturated ones and nitriles to the corresponding aldehydes. In addition to that, thexylbromoborane shows good stereoselectivity toward cyclic ketones, much better than the chloro-derivative.

• Korean Chemical Engineering Research
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• v.56 no.2
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• pp.275-280
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• 2018

Methyl ester derived from coconut oil is very interesting to study since it contains free-fatty acid with chemical structure of medium carbon chain ($C_{12}-C_{14}$), so the methyl ester obtained from its part can be a biodiesel and another partially into biokerosene. The use of heterogeneous catalysts in the production of methyl ester requires severe conditions (high pressure and high temperature), while at low temperature and atmospheric conditions, yield of methyl ester is relatively very low. By using microwave irradiation trans-esterification reaction with heterogeneous catalysts, it is expected to be much faster and can give higher yields. Therefore, we studied the production of methyl ester from coconut oil using CaO catalyst assisted by microwave. Our aim was to find a kinetic model of methyl ester production through a transesterification process from coconut oil assisted by microwave using heterogeneous CaO catalyst. The experimental apparatus consisted of a batch reactor placed in a microwave oven equipped with a condenser, stirrer and temperature controllers. Batch process was conducted at atmospheric pressure with a variation of CaO catalyst concentration (0.5; 1.0; 1.5; 2.0, 2.5%) and microwave power (100, 264 and 400 W). In general, the production process of methyl esters by heterogeneous catalyst will obtain three layers, wherein the first layer is the product of methyl ester, the second layer is glycerol and the third layer is the catalyst. The experimental results show that the yield of methyl ester increases along with the increase of microwave power, catalyst concentration and reaction time. Kinetic model of methyl ester production can be represented by the following equation: $-r_{TG}=1.7{\cdot}10^6{_e}{\frac{-43.86}{RT}}C_{TG}$.

• Food Science and Biotechnology
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• v.14 no.3
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• pp.392-398
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• 2005

Fresh, and sun- and oven-dried red peppers were analyzed for volatile components. Also, their odor-active compounds were determined using gas chromatography-olfactometry (GC-O). More diverse volatile components, such as aldehydes, ketones, acids, and esters, were found in dried samples than in fresh ones. They included hexanal, ethyl acetate, ${\alpha}$-ionone, and ${\beta}$-ionone. Some Strecker aldehydes, 2-methyl butanal and 3-methyl butanal, were found only in dried red peppers. More hydrocarbons of high volatility and terpene-type components, such as ${\gamma}$-terpinene and aromadendrene, were detected only in fresh red peppers. A considerable amount of naphthalene was formed during sun-drying, whereas 2-furancarboxaldehyde, 1-methyl-1H-pyrrole and benzeneethanol were detected only in oven-dried red peppers. Characteristic odor of fresh ones could be attributed to 3-penten-2-o1, 2-methyl-2-butenal, 2-methoxy phenol, 2-hydroxy-methyl-benzoate, and 2-phenoxy ethanol, whereas some odorants, including 2-pentyl furan, naphthalene, hexyl hexanoate, and ${\alpha}$-ionone, could be responsible for distinctive odor property of sun-dried red peppers. 2-Furancarboxaldehyde, benzeneethanol, 4-vinyl-2-methoxy phenol, and unknown played important roles in odor property of oven-dried red peppers.

• Parasites, Hosts and Diseases
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• v.54 no.2
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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.

• Korean Journal of Food Science and Technology
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• v.21 no.4
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• pp.562-568
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• 1989

The essential oils from ripe fruit peel and leaf of Zanthoxylum piperitum DC were extracted by gas co-distillation method and analyzed by gas chromatography/mass spectrometry (GC/ MS) and retention index matching. The experimental results revealed the presence of over 100 volatile components. Major components were 1,8-cineol (25.47%), limonene (11.91%), geranyl acetate (9.01%), myrcene (6.15%) in fruit peel and citronellal (23.11%), 1,8-cineol (18.38%), citronellol (6.04%) in leaf. Among the components identified were the following; in fruit peel, ${\alpha}-pinene$ and 13 hydrocarbons, linalool and 8 alcohols, citronellal and 3 aldehydes, carvone and 2 kotones, methyl salicylate and 7 esters, and 1,8-cineol and oxides, and in leaf, ${\alpha}-pinene$ and 7 hydrocarbons, linalool and 7 alcohols, citronellyl acetate and 5 esters, citronellal and 1 aldehyde, carvone, and 1,8-cineol and 1 oxide.