• Applied Biological Chemistry
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• v.50 no.4
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• pp.327-333
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• 2007

This study was conducted to examine antioxidant activities of Perilla frutescens var. acuta leaf. For the this purpose, DPPH radical scavenging activity, lipid oxidation inhibition, SOD-like activity, and xanthine oxidase inhibitor activity of water extract, ethanol extracts (30, 50, 70, and 95%) and the fractions obtained from these extracts were determined. The electron donating abilities of the chloroform fraction obtained from the 70% and 95% ethanol extracts were 50%, and that of the ethyl acetate fraction for all of the extracts was above 75%. In particular, the electron donating ability of the ethyl acetate fraction of the 70% ethanol extract showed the greatest activity with 200.5 ppm of $RC_{50}$ value. The 70% ethanol extract was most effective to inhibit the automatic oxidation of linoleic acid at $40^{\circ}C$ storage. The highest inhibition effects appeared in the chloroform and ethyl acetate fractions of the water extract, and the 30, 50, and 70% ethanol extracts, and the highest lipid oxidation inhibiting effect of the 95% ethanol extract occurred in the hexane and acetate fractions. The SOD-like activity of the water extract was 30.3%, and the activities of the various concentration of ethanol extracts were 28-32% and the activity of the 70% ethanol extract was the highest. The SOD-like activity of the ethyl acetate fraction of the 70% ethanol extract was highest with 1,549.0 ppm of $RC_{50}$ value. Xanthine oxidase inhibition activity was greatest in the water extract and the activities of the ethanol extracts were 36-41.2%. The xanthine oxidase inhibition activity of the ethyl acetate fraction of the water extract was highest. In summary, we found that electron donating ability, lipid oxidation inhibition, and SOD-like activity of Perilla frutescens var. acuta leaf were greatest in the ethyl acetate fraction of the 70% ethanol extract, and xanthine oxidase inhibition activity was highest in the ethyl acetate fraction of the water extract.

• Proceedings of the Korean Fiber Society Conference
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• 2000.04a
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• pp.5-8
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• 2000

• Journal of the Korean Graphic Arts Communication Society
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• v.11 no.1
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• pp.31-43
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• 1993

• Proceedings of the Materials Research Society of Korea Conference
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• 2002.11a
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• pp.117-117
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• 2002

• Bulletin of the Korean Chemical Society
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• v.22 no.1
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• pp.113-116
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• 2001

• Korean Chemical Engineering Research
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• v.54 no.5
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• pp.698-705
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• 2016

Butyl acetate is produced from acetic acid and butanol via an esterification reaction in reactive distillation (RD). The product, butyl acetate, has been used as an internal entrainer until now. In this case, butyl acetate and water are removed at the top of column and separated into two different phases (organic and aqueous phases) after condensation, and butyl acetate rich organic phase is refluxed into the RD. This method makes butyl acetate remain high at the reactive zone, leading to lower equilibrium conversion and product yield. We introduced an extraneous entrainer to solve the problem. The extraneous entrainer forms a new azeotrope with water. The proposed process provides lower concentration of butyl acetate in the reactive zone than conventional RD processes using an internal entrainer. We compared the yield and production rate of butyl acetate between the proposed and conventional processes through pilot-scale experiments. Experimental and simulation results showed that the proposed process was more efficient than conventional process using internal entrainer.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.7
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• pp.1205-1212
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• 2000

The effect of temperature on the sources of organic acids and sludge when phosphorus was biologically released was evaluated in this study. The sludge used in this study was obtained from sequencing batch reactor processing the swine wastewater. Temperature is one of the most important parameters influencing the phosphorus release. As a result, the rate of phosphorus released was increased as the temperatures were increased from 5 to $30^{\circ}C$ regardless of the sources of organic acids used. Under anaerobic conditions, as acetate, propionate, glucose, and domestic wastewater were used as the sources of organic acids, the corresponding activation energy($E_a$) values were 49.83, 55.82, 54.61, and 45.44 KJ/mol, respectively. Temperature coefficient($\theta$) values were 1.0676, 1.0826, 1.0748, and 1.0698, respectively. Therefore, the rate of phosphorus released was increased as temperature was increased, whereas, the effect, of the sources of organic acids and temperature on the activation energy and temperature coefficient values were minimal. When the sludge previously adapted to acetate as external organic source was used, the activation energy and temperature coefficient values were 44.94 KJ/mol and 1.0570 respectively. The effect of temperature was minimal. These values obtained from the sludge previously adapted to acetate were smaller than those from the sludge not previously adapted to the same organic acid. This suggest that the sludge previously adapted to acetate was less dependent on temperature than that not adapted to the acetate.

• Korean Journal of Plant Resources
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• v.29 no.2
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• pp.163-170
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• 2016

Antioxidant activity and inhibitory effect on oxidative DNA damage of ethyl acetate fractions extracted from Cone of Red Pine (Pinus densiflora) were investigated to find utilization of Cone, by-product of Red Pine, thrown out after berry shatter, as a new natural plant resource. Cone from P. densiflora was extracted with methanol (MeOH) and separated to petroleum ether, ethyl acetate and water fraction. Among them, ethyl acetate fraction was used. The antioxidant activity was conducted by the 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical, 2, 2'-Azino-bis (3-ethylbenzothiazoline-6 sulfonic acid) diammonium salt (ABTS) radical scavenging assay, Fe²⁺ chelating assay and reducing power assay. The inhibitory effect on oxidative DNA damage was determined by DNA cleavage assay using φX-174 RF I plasmid. The results of DPPH and ABTS radical scavenging activity at 200 ㎍/㎖ of extracts were 86.50% and 95.80% respectively, which were similar figures compared with L-ascorbic acid as control. Fe²⁺ chelating activity was 77.96% and reducing power was 0.77 at 200 ㎍/㎖. Total phenolic component was 27.29±0.3 ㎎/g and Vitamin C content was 1.84±0.1 ㎎/g. Also ethyl acetate fraction from Cone has inhibitory effect, using φX-174 RF I plasmid on DNA cleavage assay. In conclusion, Cone, by-product of P. densiflora, showed high antioxidant activity and inhibitory effect on oxidative DNA damage. Therefore this study suggests Cone, useless by-product, can be developed as a new natural plant resource with lots of utilization such as an effective antioxidant, natural medicine, food, cosmetics and so on.

• The Korean Journal of Ecology
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• v.28 no.3
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• pp.135-139
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• 2005

This study was carried out to find the allelopathic effect of volatile materials released from Eupatorium rugosum. The GC method was employed for analysis of volatile materials from E. rugosum and 49 chemical substances were identified such as $\beta$-caryophyllene, $\alpha$-terpinenol, chamazulene, bornyl acetate, $\alpha$-pinene, etc. including unidentified three chemicals. Germination test in Phaseolus radiatus was done to find the inhibition effect of volatile materials using some chemicals which were proved to be important component or much amounts ones in E. rugosum. It was strongly inhibited by linalool and terpinen-4-ol. Seedling elongation and radicle growth of that were proportionally inhibited by the concentration of the essential oil, especially $\alpha$-pinene and bornyl acetate. Biomass of receptor plant was slightly decreased more than 58 ${\mu}l$ of the extract in case of $\alpha$-pinene, while it was decreased more than 19 ${\mu}l$ of that in bornyl acetate but it was shown non-significant. From the above results, it was found that volatile materials from E. rugosum showed a allelopathic effect and also $\alpha$-pinene, bornyl acetate, linalool and terpinen-4-ol used in bioassay were some of major allelochemicals in germination inhibition and especially linalool and terpinen-4-ol are prominent effect on growth inhibition of other plant.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.10
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• pp.1338-1345
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• 2012

This study investigated the antioxidant activities, whitening effects, and antimicrobial activities of fractions from Pleurospermum kamtschaticumin extract. Total polyphenolic contents of fractions from Pleurospermum kamtschaticumin extract were 116.44~382.73 mg/g GAE (gallic acid equivalent), with the highest value in the ethyl acetate fraction. Fractions of Pleurospermum kamtschaticumin showed the highest DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity ($IC_{50}$=0.04 mg/mL) and ABTS radical scavenging activity (98.86% at 0.5 mg/mL), which was similar to ascorbic acid. Further, reducing power and FRAP activity were significantly high in the ethyl acetate and n-butanol fractions. The ethyl acetate and n-butanol fractions showed significantly high SOD-like activities (1 mg/mL, 86.93%, and 78.23%, respectively) compared to other fractions. Tyrosinase inhibition activities of the n-butanol fraction and 80% ethanol extract were 43.52% and 41.64%, respectively. Antimicrobial activity against Escherichia coli was only observed in the chloroform fraction (16.7 mm in 0.5 mg/disc). These results suggest that fractions from Pleurospermum kamtschaticumin extract show comparatively high antioxidant activity and thus could be used as a food additive or cosmeceutical ingredient.