• Journal of Marine Bioscience and Biotechnology
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• v.10 no.2
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• pp.44-52
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• 2018

A synthetic pathway, which consisted of fatty acid double bond hydratase, alcohol dehydrogenase, and Baeyer-Villiger monooxygenase, was applied to Chlorella oil to produce ester fatty acids, which can be hydrolyzed into medium chain fatty acids. Since linoleic acid is a major fatty acid constituent of Chlorella oil, a fatty acid double bond hydratase from Lactobacillus acidophilus NBRC13951, which is able to convert linoleic acid into 13-hydroxyoctadec-9-enoic acid, was used. Recombinant Escherichia coli expressing the fatty acid double bond hydratase from L. acidophilus NBRC13951 successfully transformed linoleic acid in Chlorella oil hydrolysates into 13-hydroxyoctadec-9-enoic acid with approximately 60% conversion yield. 13-Hydroxyoctadec-9-enoic acid was further converted into ester fatty acids by the recombinant E. coli expressing a long chain secondary alcohol dehydrogenase and a Baeyer-Villiger monooxygenase. The resulting ester fatty acids were then hydrolyzed into medium chain fatty acids by a lipase. Overall, industrially relevant medium chain fatty acids were produced from Chlorella oil hydrolysates. Thereby, this study may contribute to biosynthesis of medium chain fatty acids from microalgae oils as well as long chain fatty acids.

• Bulletin of the Korean Chemical Society
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• v.31 no.11
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• pp.3313-3317
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• 2010

A simple and efficient synthetic route for making purpurin-18-N-aminoimides is described. The purpurin-18-Naminoimides are obtained by treatment of purpurin-18 methyl ester with various amines. These new compounds have long wavelength absorptions in the range of 706 - 711 nm. In preliminary screening, the purpurin-18-N-aminoimides have shown promising photosensitizing activity for the cancer cell by in vitro study in photodynamic therapy.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.252.1-252.1
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• 2003

Systematic investigations to develop an efficient enantioselective synthetic method for a-alkyl-alanine by the catalytic phase-transfer alkylation were performed. The alkylation of 2-naphthyl aldimine tert-butyl ester, 1 E with RbOH and O(9)-allyl-N-2'3'4'-trifluorobenzylhydrocinchonidinium bromide, 6, at \ulcorner5 \ulcorner\ulcorner showed the highest enantioselectivities, up to 96％ ee.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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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 Pharmaceutical Investigation
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• v.14 no.2
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• pp.76-85
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• 1984

Antibiotic activity and antipyretic effect of three synthetic prodrugs, chloramphenicol acetylsalicylate (CAF-ASP), chloramphenicol naproxenate(CAF-NAX) and chloramphenicol acetaminophen succinate (CAF-SUC-ACET), were studied in vitro and in vivo. In the experimental results, the CAF-NAX showed the moat rapid absorption and the highest blood levels, and the CAF-SUC-ACET and CAF-ASP also were more rapid absorption and higher blood levels than controls, chloramphenicol and chloramphenicol palmitate. The synthetic prodrugs also showed the antipyretic effect by modified Roszkowski method using endotoxin.

• YAKHAK HOEJI
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• v.47 no.3
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• pp.130-134
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• 2003

For the development of new synthetic method for unnatural amino acid esters, N-aryl phenylglycine Ο-alkyl esters 4a∼i were synthesized through base-catalyzed hydrolysis of 1,5-diphenylhydantoins 1a∼b and Ο-alkylation in 16∼87％ yield. An efficient and practical route for final 4a∼i was that the starting materials 1a∼b were heated in dil-methanol for 30 minute using sodium hydroxide or potassium hydroxide and evaporated. In addition, reaction mixture were refluxed for 1 h in DMF. All synthetic process from hydantoin to N-aryl phenylglycine Ο-alkyl esters 4a∼i could be carried out in one-pot without isolation of intermediates.

• Journal of the Korean Applied Science and Technology
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• v.27 no.4
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• pp.522-530
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• 2010

We developed functional synthetic lubricant for internal combustion engine oil, which would improve engine oil performance for internal combustion engine and extend engine life. We made base oil by synthesizing nonanoic acid, 1.1.1-trimethylol propane (which has good bio-degradability) and pentaerythrytol ester. We synthesized catalyst using p-toluene sulfonic acid 0.15 wt% and coloring-prevention agent hypo-phosphorus acid 0.18 wt% at 180-$190^{\circ}C$. Reaction temperature was increased at the rate of $10^{\circ}C$ for every 1 hour. When acid value reached below 3, reaction was completed. After cooling and deoxidization, we washed it by distilled water two times. After dehydration and filtering, we obtained trimethylol propane tripelargonate (TMTP) and pentaerythrytol tetrapelargonate (PETP) at yields of 96 % and 98 % respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.s01
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• pp.26-32
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• 1989

The analytic principles of GC and MS were explained in relation to plant hormone analyses and the characteristics of two instruments were compared. The selection of column, condition of measurement and the method of ionization to get a good spectrum were also briefly described. Finally, the pre-treatment of sample by solvent extraction method to remove the unnecessary part of sample and the synthetic method, especially reagents and reaction condition, for the preparation of ether or ester derivative which can be easily vaporized in GC were explained.

• Archives of Pharmacal Research
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• v.27 no.8
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• pp.811-815
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• 2004

Coumarin and its derivatives occur widely in nature. Many attempts were made for synthesis of various coumarin derivatives because of their interesting biological activities. In this study, solid phase synthetic approach of 3-(4-hydroxyphenyl)coumarin was achieved for combinatorial synthesis of substituted 3-phenylcoumarin analogues. Starting from 4-hydroxyphenylacetic acid methyl ester, release of 3-(4-hydroxypnehyl)coumarin from polymer support was accom-plished.

• Bulletin of the Korean Chemical Society
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• v.34 no.3
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• pp.868-874
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• 2013

Efficient synthetic route to novel 2'-spirocyclopropanoid 4'-deoxythreosyl phosphonic acid nucleosides was described from 1,4-dihydroxy-2-butene. Cyclopropane moiety was prepared via ester enolate alkylation using (2-chloroethyl)dimethylsulfonium iodide. Synthesized nucleoside analogues 16, 19, 23 and 26 were tested for anti-HIV activity as well as cytotoxicity. However, none of them showed any anti-HIV activity or cytotoxicity up to 100 ${\mu}M$.