• Membrane Journal
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• v.10 no.4
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• pp.186-191
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• 2000

The recovery of three ethyl esters (aroma model compounds; ethyl acetate, ethyl propionate. ethyl butyrate) from aqueous solutions was studied for vapor permeation with surface-modified hydrophobic alumina membrane, Although the driving force of ethyl butyrate is the highest, the ethyl butyrate concentration in permeate is lower than those of propionate and acetate. Since the solubility of aroma compounds for water is very low, phase separation occurred in permeate, and we could obtain pure ethyl esters. The experimental results showed that the porous hydrophobic alumina membrane had high selectivity and permeation flux on the ester-model compounds.

• YAKHAK HOEJI
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• v.33 no.2
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• pp.80-86
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• 1989

2,6-Dimethyl-4-(3'-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid 3-methyl 5-(2'-phenylsulfinyl) ethyl ester (10) or 2,6-Dimethyl-4-(2' or 3'-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid 3-alkyl 5-(2-methylsulfonyl) ethyl ester (14a, b, c) were hydrolyzed by treatment with NaOH in aqueous EtOH solution to give 2,6-Dimethyl-4-(3'-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid monomethyl ester (4b), 2,6-Dimethyl-4-(2'-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid monomethyl ester (4c) and 2,6-Dimethyl-4-(2'-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid monoisopropyl ester (4d) in 80 -90% yield. By the same procedure, 2,6-Dimethyl-4-(3'-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid 3,5-bis (2'-methylsulfonyl) ethyl ester (15) gave 2,6-Dimethyl-4-(3'-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid (4e) in 96% yield.

• Journal of Pharmaceutical Investigation
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• v.36 no.4
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• pp.223-229
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• 2006

[ $PGE_1$ ]-ethyl ester intraurethral solutions were prepared in ethanol/propylene glycol mixture with penetration enhancer and viscosity-enhancing agent. The stability of $PGE_1$-ethyl ester in intraurethral solution was investigated at various temperature. Simultaneous determination of $PGE_1$-ethyl ester and $PGE_1$ was performed using a validated HPLC technique. In pentobarbital anesthetized cats, increase in intracavernous pressure(ICP), increase in penile length and duration of erectile response were determined after intraurethral application of $PGE_1$-ethyl ester solutions. $PGE_1$-ethyl ester solutions, when instilled into the eyes of rabbits, produces no noticeable irritation, or slight transient conjunctival irritation. From these results, ocular irritation of this solutions was judged as practically non-irritating. The stability study indicates that the therapeutically effective content in solution is well maintained for 46 weeks or longer when they are stored at $4^{\circ}C$. After intraurethral application of $PGE_1$-ethyl ester, ICP was increased and penile erection was induced. $PGE_1$-ethyl ester intraurethral solutions for erectile dysfunction could be developed and evaluated by employing feline erection model.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.9
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• pp.1122-1127
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• 2017

Currently, the consumer trends are increasing towards "natural" in all food systems. Therefore, in the flavor industry, the production of flavor esters by "natural" methods are needed. On the other hand, "natural flavor" is expensive to produce because of the limited natural source. Recently, the flavor obtained from the enzyme or microbial could be represented as "natural flavor". Ethyl butyrate is used most frequently as a fruity aroma in drinks and the processed food industry. In this study, ethyl butyrate was synthesized enzymatically using the ester synthetase obtained from the waste of pineapple and banana peel. The ethyl butyrate production optimization was analyzed using a response surface methodology. The enzyme reaction variances were composed of the ethanol content, butyric acid content, and reaction time. As a result, in ester synthetase obtained from banana peel, the maximum predicted production amounts were 45.8199 mM at an ethanol content of 38.7050 mM, butyric acid content of 50.9019 mM, and reaction time of 4.3662 h. In ester synthetase obtained from pineapple peel, the maximum predicted production was 65.1087 mM at an ethanol content of 54.6502 mM, butyric acid content of 58.7638 mM, and reaction time of 4.7436 h. In conclusion, ethyl butyrate production was shown the more useful using the ester synthetase obtained from pineapple peel than that from banana peel.

• Journal of the Korean Chemical Society
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• v.35 no.6
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• pp.725-729
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• 1991

Unsaturated all-cis-5,8,11,14-eicosatetraenoic(arachidonic), 7,10,13-hexadecatrienoic, 10, 13-octadecadienoic acid ethyl ester and a lot of chimyl alcohol were isolated along with common 9-hexadecenoic acid ethyl ester from marine mollusca Bullacta exarata collected from sangnackworl island in the Korea sea. In addition, cholesterol and its fatty acid ester were obtained. Their structures were deduced from $^1H-$and $^{13}C$-NMR, GC-ms, and FT-IR spectra.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.6
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• pp.654-659
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• 2002

To investigate the effects of preparation conditions of encapsulating ester compounds on retention rate of core material in microcapsules prepared with sea tangle alginate, the amounts of ester compounds migrated gelling solution (1 M $CaCl_2$) and washing water from microcapsules that were prepared by adding kinds of ester compound, by controlling ratios of emulsifier to ester compounds and by differing ratios of alginates (wall material) to ester compounds (core material) were measured. Also the amount of ester compounds retained in microcapsules was measured. The higher weight molecular of ester compounds were, the lower amounts of ester compounds migrated gelling solution and washing water from microcapsules were, But its amounts retained in microcapsules were increased, The changes of ethyl caprylate amount migrated gelling solution and washing water from microcapsules prepared by increasing ratios of emulsifier to ethyl caprylate were little, but its half-lives in microcapsules during storage at 25$^{\circ}C$ were steeply increased. Increasing ratios of wall material to core material, ethyl caprylate amount migrated gelling solution and washing water from microcapsules showed 1.8$\~$$2.0\%$ and 2.9$\~$$3.5\%$ respectively but half-lives of ethyl caprylate retained in alginate microcapsules were increased.

• Applied Chemistry for Engineering
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• v.10 no.1
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• pp.135-137
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• 1999

For the synthesis of new anti-inflammatory agents as indol derivatives, we have synthesized ${\alpha}$-benzoyl-1-ethyl-1,3,4,9-tetrahydro-8-ethyl-9-(N-benzoyl)pyrano[3,4-b]indole-1-acetic acid methyl ester. It was a new method for ${\alpha}$-substituted etodolac carboxylic acid. The synthetic process was composed of four steps, and 7-ethylindole and oxalyl chloride were used as starting materials. The third step, cyclization was carried out by addition of borontrifluoride diethyl etherate in 66% yield. The step of reduction and cyclization were simplified successfully. The final product, ${\alpha}$-benzoyl-1-ethyl-1,3,4,9-tetrahydro-8-ethyl-9-(N-benzoyl)pyrano[3,4-b]indole-1-acetic acid methyl ester was obtained in 66% yield by the reaction of methyl 1,8-dimethyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetate (etodollic acid methyl ester) and benzoyl chloride.

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.316-323
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• 1996

Flavor components in mash of Takju prepared by different raw materials such as nonglutinous rice, glutinous rice, barley and wheat flour were detected by GC and GC-MS method using non-polar column. Seven alcohols, 15 esters, 10 organic acids, 1 aldehyde, 4 benzenes, 3 phenols, 8 alkans, 2 ketones and 5 others were found in takju after 16 day of fermentation. takju by wheat flour had the most various components of volatile flavor. Treatment with addition starter had less flavor component than that without addition starter in takju by nonglutinous rice. Nine kinds of flavor components including acetic acid ethyl ester, 3- methyl-1-butanol, acetic acid, ethyl benzene, acetic acid 3-methyl butyl ester, 2-phenylethanol, 2,6-di-tert-butyl-4-methyl phenol. plumbagic acid and 1,2-benzenedicarboxylic acid dibutyl ester were commonly detected in all the treatments. Especially, 2,4,0-trimethyl-1,3-benzenediamine was isolated in takju that was made of nonglutinous rice without addition starter. Diethyl sulfide, 4-methoxy benzaldehyde, docosane and 2-methyl propyl octadecanoic acid were isolated from takju by nonglutinous rice with addition starter. Propionic acid ethyl ester, acetic acid butyl ester, 2-methyl butane and 3-methyl pentane were isolated from takju glutinous rice. 2-Hydroxy-4-methyl pentanoic acid and 2-methyl tridecane were isolated from akju by barley 3-(Methylthio)-1-propanol. hexanoic acid ethyl ester, butanoic acid monomethyl ester, tridecanoic acid, ethyl tetramethyl cyclopentadiene and 1,5-diaza-2,9-diketocyclotetradecane were isolated from takju by wheat flour. Major volatile flavor components were acetic acid ethyl ester, 3-methyl-1-butanol, acetic acid and 2-phenylethanol.

• Food Science of Animal Resources
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• v.23 no.3
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• pp.209-214
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• 2003

This study was carried out to investigate the influence of dietary xanthophylls(lutein and apocarotenoic acid ethyl ester) supplementation on the antioxidation of broiler meat. The broilers fed with 10 ppm or 20 ppm xanthophylls were raised for 6 weeks and then slaughtered. The broiler meats were stored at 3$^{\circ}C$ for 9 days and frozen at -18$^{\circ}C$ for 4 months until analysis, respectively. The pH of all treatments significantly(p<0.05) increased during the storage periods. The pH of the thigh was higher than that of the breast. TBARS (thiobarbituric acid reactive substance) and POV(peroxide value) were higher in thigh than breast. All meats from broiler fed with lutein and apocarotenoic acid ethyl ester(apo-ester) had greater antioxidant properties during the storage period than control meat(p<0.05). Antioxidant activity of dietary xanthophylls supplementation was more effective in thigh than breast, and in broiler meats during frozen storage than chilled storage. The higher concentration of xanthophylls in feed, the more inhibition of lipid oxidation in meat during storage. The meat from broiler fed with 20 ppm of lutein showed the highest antioxidant property during both refrigerated and frozen storage although there was no significant difference between lutein and apo-ester(p>0.05). Consequently, this results indicated that the antioxidant activity of dietary xanthophylls(lutein and apocarotenoic acid ethyl ester) supplementation was more effective.

• Food Science and Preservation
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• v.18 no.5
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• pp.721-728
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• 2011

1(3)-palmitoyl-2-oleoyl-3(1)-stearoyl-(POS)-glycerol-enriched reaction products were synthesized from camellia oil, palmitic ethyl ester, and stearic ethyl ester via lipase-catalyzed interesterification. Response surface methodology (RSM) was employed to optimize the production of the POS-enriched reaction product (Y1, %) and the stearicand palmitic-acid contents at the sn-2 position due to acyl migration (Y2, %). The reaction factors were the enzyme amount (X1, 2-6%), reaction time (X2, 60-360 min), and substrate molar ratio of camellia oil to palmitic ethyl ester and stearic ethyl ester (X3, 1-3 mol). The predictive models for Y1 and Y2 were adequate and reproducible as no lack of fit was signified (0.128 and 0.237) and as there were satisfactory levels of R2 (0.968 and 0.990, respectively). The optimal conditions for the reaction product for maximizing Y1 while minimizing Y2 were predicted at the reaction combination of 5.86% enzyme amount, 60 min reaction time, and 1:3 substrate molar ratio (3 moles of palmitic ethyl ester and 3 moles of stearic ethyl ester). Actual reaction was performed under the same conditions as above, and the resulting product contained 20.19% TAG-P/O/S and 12.71% saturated fatty acids at the sn-2 position.