• Journal of the Korean Chemical Society
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• v.55 no.3
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• pp.373-378
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• 2011

The present paper reports the study of binary mixtures and their properties over the entire range of composition at temperatures 288, 298, 308 and 318 K. Excess dielectric constant, excess molar volume, excess refractive index, molar refraction and excess molar refraction at different temperatures have been computed from the experimentally measured values of the aforesaid parameters and fitted to the Redlich-Kister equation. Excess dielectric constant, excess molar volume excess molar polarizations are negative whereas excess refractive indices are positive over entire mole fraction of methyl acetate for all temperatures. The results are discussed in light of intermolecular interactions occurring in the binary mixture. Estimated coefficients of the Redlich-Kister polynomials and the standard error along the coefficients are also reported.

• Journal of the Korean Wood Science and Technology
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• v.34 no.3
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• pp.64-72
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• 2006

Two compounds were isolated from the diethylether and ethyl acetate fraction of hot water extracts by TLC and column chromatography as dyeing components. The isolated compounds were characterized as H-dibenzoquinoline-2,10-diol,5,6,6a,7-tetrahydro-1,9-dimethoxy-6-methyl (compoundI) and lyoniresinol (compoundII) by NMR and Mass spectrophotometry. To investigate if the isolated compounds are involved in the dyeing process, HPLC analysis was used. The retention time of the components from dye used in the study and the dye decolorized from the dyed substrate, silk by ethyl acetate were compared to conform the identity of those compounds. The retention time of the components from the dye and decolorized solution were identical. As a results, those two compounds were considered as dye bound to the silk.

• Preventive Nutrition and Food Science
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• v.18 no.1
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• pp.76-79
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• 2013

We evaluated antioxidant activities of heated pear juice (HPJ) exposed to 120, 130, and $140^{\circ}C$ for 2 hr. HPJ was partitioned using n-hexane, chloroform, ethyl acetate, n-butanol, and water. The ethyl acetate fraction treated at $130^{\circ}C$ for 2 hr showed strong antioxidant activity; thus, this extract was isolated and purified using silica gel column chromatography and preparative high performance liquid chromatography. The structure of the purified compound was determined using ultraviolet and mass spectrometry, $^1H$-nucelar magnetic resonance (NMR), and $^{13}C$-NMR. Antioxidant activities of the isolated compound were evaluated and compared with ${\alpha}$-tocopherol, ascorbic acid, and butylated hydroxytoluene (BHT) using DPPH and ABTS assays. The isolated compound was identified as 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP). The DPPH radical-scavenging activity ($IC_{50}$) of DDMP occurred in the following order: ascorbic acid ($45.3{\mu}g/mL$) > ${\alpha}$-tocopherol ($69.2{\mu}g/mL$) > DDMP ($241.6{\mu}g/mL$) > BHT ($268.0{\mu}g/mL$). Furthermore, DDMP showed strong ABTS radical-scavenging activity (569.0 mg AA eq/g).

• Korean Journal of Food Science and Technology
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• v.21 no.1
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• pp.127-135
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• 1989

The volatile components of nutmeg, cumin, cardamon, turmeric, coriander, clove, allspice, cassia, fennel, celery seed and black pepper, having a characteristic spicy aroma and being used as an ingradient of curry powder, were investigated. After steam distillation followed by extraction with diethyl ether: n-pentane(2:1, v/v) mixture, the volatile components were identified by capillary GC and GC/MS. As a result, following major compounds were identified. ${\alpha}-pinene(11.06%)$, ${\beta}-pinene(11.17%)$ and myristicin(19.98%) in nutmeg, cuminaldehyde(37.68%) in cumin, ${\alpha}-terpineol(47.33%)$ and 1, 8-cineol(20.56%) in cardamon, linalool(61.72%) in coriander, eugenol(63.63%) and eugenol acetate(20.59%) in clove, eugenol(80.12%) and methyl eugenol(10.85%) in allspice, cinnamaldehyde(82.29%) in cassia, anethole(79.92%) in fennel.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.5
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• pp.373-377
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• 1990

Volatile components of whole sardine sauce which was prepared with $7\%$ of complex enzyme-2000($2.18{\cdot}10^4\;U/g solid$), mixed with $6\%$ of invert sugar and heated at $90^{\circ}C$ for 2 hours were compared with those of without invert sugar. Thirty seven kinds were identified from the whole volatile components of hydrolysate heated without invert sugar and fourty three kinds were identified from the hydrolysate heated with $6\%$ of invert sugar. Amines were not detected from the whole volatile components of the chopped whole sardine hydrolysate. Considerable amount of 2,3-dihydrobenzofuran and 2-acetylpyrrole, a little amount of 2,5-hydrofuran, 2-ethylbutanol, 2-pyrone, 2-acetylfuran, 2,6-dimethylpyrazine, 2-acetylpyrazine, 5-methyl-2-furfural, furfuryl acetate, butylpyrrole and 2-methyl-3-hydroxypyrone were detected in the hydrolysate thermally treated with $6\%$ of invert sugar while these were not found in the hydrolysate heated without invert sugar. But the amount of 2-methyt-1-propa-not, hexane, butyl acetate and butyl alcohol were decreased, and acetic acid and butanoic acid were detected as volatile fatty acids.

• Nuclear Engineering and Technology
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• v.4 no.1
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• pp.23-30
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• 1972

A study on the preparation of wood-plastic combinations by gamma-ray induced polymerization is carried out. In monomer impregnation, the rates and amounts are determined for various woods. The polymerization rates of various monomers and monomer mixtures impregnated mainly domestic woods are studied varying the total gamma-dose and gamma-dose rates. The obtained data indicate that; 1) in impregnation of monomer, populus deltoides is the fastest in rate, and the most impregnated in amount 2) the general trends of polymerization of monomers ill woods is in the order of vinyl acetate--methyl metacrylate--styrene, ranging from 3 to 15 Mard of total does in rate of 4$\times$10$^4$rad/hr., thus vinyl acetate or methyl metacrylate is suitable monomer in view of polymerization rate, 3) the successful woods in combination with monomer are pinus rigida and pinus densiflora in view of polymerization rate, 4) the monomers in woods are more easily polymerized under the conditions of moderately lower does rate, 2.1$\times$10$^4$rad/hr.

• Applied Chemistry for Engineering
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• v.29 no.6
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• pp.799-804
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• 2018

The separation and purification of 2,6-dimethylnaphthalene (2,6-DMN) present in the light cycle oil (LCO) fraction was investigated by a crystallization operation. Solute crystallization (SC) was performed using LCO fraction and iso-propyl alcohol as a raw material and a SC solvent, respectively. Increasing the operation temperature and volume ratio of the solvent to the raw material (S/F) resulted in improving the purity of 2,6-DMN, whereas the yield decreased. As a result of the crystallization operation in three steps containing the SC using LCO fraction (13.9% 2,6-DMN) and isopropyl alcohol, the re-crystallization 1 (RC 1) using the crystals recovered by SC and methyl acetate, and RC 2 using the crystals recovered by RC 1 and methyl acetate, the crystal with 99.9% 2,6-DMN was recovered with 19.5% yield. Furthermore, the separation and purification process of 2,6-DMN present in the LCO fraction was reevaluated by using the experimental results obtained through each operations of SC, RC 1, and RC 2.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.9 no.1
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• pp.156-172
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• 1999

Potential chemical hazards encountered in painting operation of four shipyards and a ship-repair shop were investigated through the material safety data sheets (MSDS). Material safety data sheets (MSDS) for 307 paints, 50 thinners and 34 binders were collected and reviewed. It was shown that various organic solvents such as aromatic hydrocarbons, aliphatic hydrocarbons, ketones, alcohols, glycols, glycol ether acetates and esters were contained in painting materials. Of these solvents, xylene was found in the largest number of painting materials. sixty percent of the thinners contained xylene in the contents of 20-100%. Other most frequently found solvents were 1-methoxypropanol, 1-methoxypropyl acetate, n-butanol, methyl isobutyl ketone, toluene, isopropanol, and n-butyl acetate, etc. Glycol ethers such as 2-methoxyethanol (2-ME), 2-methoxyethyl acetate (2-MEA), 2-ethoxyethanol (2-EE), 2-ethoxyethyl acetate (2-EEA) and 2-butoxyethanol (2-BA) were regarded as having the potential to cause adverse reproductive effects, embryotoxic effect and hematotoxic effects, and were found in some epoxy panting materials. Coal tar pitch was included in some paints(13%) where polynuclear aromatic hydrocarbons (PAHs) could be contaminated. Inorganic pigments such as lead chromate and zinc potassium chromate were found in some paints (8%). The epoxy resin based paints, which may contain isocyanates such as toluene diisocyanates and hexamethylene diisocyanates causing potential sensitization and asthma to upper respiratory organ, were mostly used in the shipyards. The constituents in the MSDS were significantly different from the results analyzed using gas chromatography/mass detector: minor constituents or impurities were omitted in many MSDS. In conclusion, xylene was the most frequent organic solvent in painting materials, and glycol ethers, including 2-ME, 2-MEA, 2-EE, 2-EEA and 2-BA, were found some products. Also, painting workers may be exposed to PAHs, lead, chromate, isocyanates, organic tin and other various chemicals. The compositions of chemicals in painting materials were variable significantly, and the hazards were changed. These facts should be considered in environmental monitoring and control of the hazards.

• Korean Journal of Environmental Agriculture
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• v.36 no.4
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• pp.263-268
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• 2017

BACKGROUND: Lespedeza cuneata G. Don is a well-known medicinal plant. In this study, the biological activities of L. cuneata extracts were investigated. METHODS AND RESULTS: L. cuneata shoot was extracted with 30% ethanol and further fractionated with organic solvents. Total phenolic and flavonoid content, antioxidant activity, and matrix metalloproteinase inhibition effect of the extract and fractions were measured. Among the tested extract and fractions, the highest contents of total phenolic and flavonoids were found in ethyl acetate fraction (117.8 mg GAE/g and 35.9 mg QE/g, respectively). Ethyl acetate fraction showed the highest DPPH and ABTS radical scavenging activity, and the antioxidant activity of the other fractions followed the order n-hexane fraction>ethanol extract>methyl chloroform>n-butanol fraction. Inhibitory effect on the expression of matrix metalloproteinases (MMP1 and MMP3) was highest in the fraction of ethyl acetate, and n-butanol fraction also significantly inhibited the expression of MMP3. Antioxidant activities of L. cuneata extracts were significantly positively related to their phenolic and flavonoid content. CONCLUSION: Ethyl acetate fraction of L. cuneata ethanol extract showed potent antioxidant and matrix metalloproteinases inhibitory activities. Those activities might be related to the high total phenolic and flavonoid content of the extract.

• Applied Chemistry for Engineering
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• v.29 no.6
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• pp.772-781
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• 2018

In this study, we investigated antioxidant, antimicrobial and cytoprotective effects of 50% ethanol extract and ethyl acetate fraction from rhizomes of Belamcanda chinensis (L.) DC. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activities ($FSC_{50}$) of the 50% ethanol extract and ethyl acetate fraction were 621.5 and $253.0{\mu}g/mL$, respectively. Total antioxidant capacities ($OSC_{50}$) of the extract and fraction were 13.6 and $3.0{\mu}g/mL$, respectively. Minimum inhibitory concentrations (MIC) of the ethyl acetate fraction for Staphylococcus aureus and Candida albicans were 156, $1,250{\mu}g/mL$, respectively, indicating similar or higher levels of those of using methyl paraben. Cytoprotective effects of the 50% ethanol extract against $^1O_2$-induced cellular damage (${\tau}_{50}$) showed in a dose dependent manner at 4 to $64{\mu}g/mL$. ${\tau}_{50}$ of the 50% ethanol extract, ethyl acetate fraction and (+)-${\alpha}$-tocopherol at $16{\mu}g/mL$ were 36.4, 45.0 and 45.8 min respectively, and the ethyl acetate fraction showed cytoprotective effects similar to (+)-${\alpha}$-tocopherol. In ultraviolet B radiation-induced HaCaT cell damage, the ethyl acetate fraction decreased intracellular reactive oxygen species (ROS) up to 45.9% at $8{\mu}g/mL$. Also in $H_2O_2$-induced HaCaT cell damage, the ethyl acetate fraction significantly increased the cell viability at $0.5{\sim}8.0{\mu}g/mL$. As a result of chemical analyses of the ethyl acetate fraction, the presence of flavonoids and polyphenol such as irisflorentin, irigenin, tectorigenin, resveratrol, iridin and tectoridin were identified. In conclusion, the extract/fraction from rhizomes of B. chinensis can be applied as a natural antioxidant and antimicrobial material to cosmetics.