• Korean Chemical Engineering Research
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• 제54권2호
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• pp.239-247
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• 2016

본 연구에서는 상용활성탄 4가지를 사용하여 산업공정에서 사용빈도가 높은 톨루엔, isopropyl alcohol (IPA), ethyl acetate (EA), 3성분계를 대상으로 흡착특성을 고찰하였다. 고찰결과 3가지 휘발성 유기화합물 중 활성탄과 가장 친화력이 낮은 IPA의 파과점이 가장 짧았으며 다음으로 EA, 톨루엔 순으로 파과점이 길어지는 것을 알 수 있었다. 가장 파과점이 짧은 IPA를 기준으로 단일성분, 2성분, 3성분계의 파과점 변화를 고찰한 결과 성분 수가 많아질수록 파과점이 낮아지는 것을 알 수 있었으며 이는 친화력이 낮은 물질이 친화력이 높은 물질에 의해 치환되는 경쟁흡착에 의한 것을 알 수 있었다. 따라서 톨루엔-IPA-EA 3성분계 흡착에서는 IPA의 파과를 기준으로 흡착탑을 설계하여야 하며 실제 산업체에서 흡착탑을 설계하는 기준도 가장 친화력이 낮은 물질을 기준으로 하여야 함을 알 수 있었다.

• 동의생리병리학회지
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• 제30권4호
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• pp.229-235
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• 2016

Sasa borealis has long been used in folk remedies and traditional Korean medicine for analgesic, sedative and anticarcinogenic purposes. To excavate novel natural compounds for treating obesity, we separated leaf and stem and fractionated. We screened phenolic contents, anti-oxidative and anti-inflammatory properties with the fractions. Dichloromethane (DCM) and ethyl acetate (EA) fraction from both leaf and stem exhibited high anti-oxidative properties demonstrated by DPPH, ABTS assay in accordance with their phenolic contents. In addition, DCM and EA fraction from leaf inhibited nitric oxide (NO) production as well as inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in Raw 264.7 cell. Finally, DCM and EA fraction from both leaf and stem significantly inhibited 3T3-L1 preadipocyte differentiation and decreased intracellular lipid level. These results suggest that DCM and EA fraction from Sasa borealis may contain therapeutic agent for obesity by attenuating inflammation and oxidative stress.

• 한국산업보건학회지
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• 제7권1호
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• pp.71-85
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• 1997

The purpose of this study was to evaluate concentrations of organic solvent mixtures in air of rotogravure printing workplaces. Qualitative and quantitative analysis of organic solvents contained in the gravure inks used at rotogravure factories had been done. The results obtained were as follows: 1. The gravure inks mainly consist of toluene, methyl ethyl ketone(MEK), and ethyl acetate(EA), and traces of isopropyl alcohol(IPA), xylene, 2-butanol, cyclohexane, cellosolve etc were also contained in them. 2. Thinner used as a diluent consist of toluene, MEK, and EA. 3. Geometric mean concentration of toluene in ambient air were 23.81 ppm at gravure printing of packing material, 42.10 ppm at gravure printing of wallpaper, 16.95 ppm at gravure printing of plastic bottle for beverage and 4.31 ppm at gravure printing of plywood printing or floor covering. Concentrations of toluene in ambient air showed statistically significant difference between types of printing. 4. Concentrations of MEK in ambient air were 12.43 ppm at gravure printing of packing material, 5.47 ppm at gravure printing of wallpaper, 16.78 ppm at gravure printing of plastic bottle for beverage and 16.44 ppm at gravure printing of plywood printing or floor covering. MEK concentrations in ambient air showed no significant difference. 5. Conentrations of EA were 14.30 ppm at gravure printing of packing material, 1.92 ppm at gravure printing of wallpaper and 21.12 ppm at gravure printing of plywood printing or floor covering. EA concentrations in ambient air shown significant difference. 6. Percentage of the workplaces where the ambient air concentration of organic solvent mixtures exceeded the Korean Permissble Exposure Level(KPEL) amounted to 18.03%. 7. Toluene concentrations in ambient air of rotogravure printing workplaces ranged from 0.69 to 156.02 ppm and urinary hippuric acid excretion ranged from 0.10 to $1.32g/{\ell}$.

• Biomolecules & Therapeutics
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• 제24권4호
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• pp.438-445
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• 2016

Cyperi Rhizoma (CR), the rhizome of Cyperus rotundus L., exhibits neuroprotective effects in in vitro and in vivo models of neuronal diseases. Nevertheless, no study has aimed at finding the neuroactive constituent(s) of CR. In this study, we identified active compounds in a CR extract (CRE) using bioactivity-guided fractionation. We first compared the anti-oxidative and neuroprotective activities of four fractions and the CRE total extract. Only the ethyl acetate (EA) fraction revealed strong activity, and further isolation from the bioactive EA fraction yielded nine constituents: scirpusin A (1), scirpusin B (2), luteolin (3), 6'-acetyl-3,6-diferuloylsucrose (4), 4',6' diacetyl-3,6-diferuloylsucrose (5), p-coumaric acid (6), ferulic acid (7), pinellic acid (8), and fulgidic acid (9). The activities of constituents 1-9 were assessed in terms of anti-oxidative, neuroprotective, anti-inflammatory, and anti-amyloid-${\beta}$ activities. Constituents 1, 2, and 3 exhibited strong activities; constituents 1 and 2 were characterized for the first time in this study. These results provide evidence for the value of CRE as a source of multi-functional neuroprotectants, and constituents 1 and 2 may represent new candidates for further development in therapeutic use against neurodegenerative diseases.

• 분석과학
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• 제19권1호
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• pp.39-44
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• 2006

보이차를 물로 추출하고, 항산화성 물질을 얻기위해 n-hexane, ethyl acetate(EA), butanol(BuOH)로 분획하였다. 분획은 자유라티칼 소거 활성과 환원력 측정의 두가지 방법으로 항산화활성 정도를 조사하였다. 이들 항산화활성을 butylated hydroxyanisole(BHA), butylated hydroxytoluene(BHT) 그리고 ${\alpha}$-tocopherol 같은 비교표준 항산화제와 비교하였다. 보이차의 EA분획은 BHA와 BHT 보다 더 높은 항산화활성을 보였다.

• 한국약용작물학회지
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• 제14권3호
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• pp.148-152
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• 2006

국내산 인삼의 부위별 quercetin, p-coumaric acid, maltol, esculetin의 함량을 측정한 결과 잎에서는 quercetin과 esculetin이 주근에서는 p-coumaric acid가 다량 함유되어 있었다. 이중잎의 EA 분획물은 melan-a 세포주에서 뛰어난 멜라닌 생성억제 활성을 보였으며, 이의 주요성분인 quercetin과 esculetin이 tyrosinase 활성억제도, melan-a 세포주에서의 멜라닌 생성억제도, UV-흡수도 측정에서 모두 우수한 활성을 나타내는 결과로 미루어 인삼의 잎은 피부미백을 목적으로 하는 기능성 소재로 이용될 수 있는 가능성을 가지는 것으로 사료된다.

• 한국식품영양학회지
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• 제32권6호
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• pp.611-619
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• 2019

The purpose of this study was to investigate the antioxidant activity and tyrosinase inhibitory activity of Codonopsis lanceolata 50% ethanol extract, and its solvent fractions (n-hexane, ethyl acetate (EA), n-butanol, water). The main components of the EA fraction were qualitatively analyzed using UPLC Q-ToF/MS. Additionally, a quantitative analysis was performed using UPLC. As a result, the total polyphenol content was 113.36 mg gallic acid/g in the EA fraction, which contained the largest amount of the C. lancolata solvent fractions. Also EA showed the highest antioxidant activity than other fractions. The IC₅₀ of DPPH(2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity was 0.03 mg/mL and the IC₅₀ of ABTS [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate)] radical scavenging activity was 0.049 mg/mL. The EA fraction showed tyrosinase inhibitory activity than other fractions and especially inhibited monophenolase oxidase reaction higher than diphenolase oxidase reaction. The monophenolase oxidase inhibited 55% when the concentration of the EA fraction was 0.25 mg/mL. As a result of Q-ToF/MS analysis, it was confirmed that tangshenoside I and lobetyolin were the main components of EA fraction. Thus, these results suggest that C. lanceolata may be used as a potent source of cosmetic agents.

• 한국수산과학회지
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• 제57권2호
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• pp.129-136
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• 2024

Lactic acid bacteria (LAB) growth in processed meat products produces slime. In this study, 10 different biofilm-forming LAB, including Leuconostoc mesenteroides, Lacticaseibacillus paracasei, Levilactobacillus brevis, Lactiplantibacillus plantarum, Leuconostoc citreum, Weissella viridescens, and Latilactobacillus sakei, were isolated from various meat products and identified based on 16S rRNA gene analysis. To inhibit biofilm formation by LABs, Eisenia bicycles methanolic extract (EB) and ethyl acetate soluble fraction (EA) were used as antibacterial and antibiofilm agents, respectively. Furthermore, EA and EB were employed to synthesize gold nanoparticles (AuNPs) such as EB-AuNPs and EA-AuNPs, which could serve as antibiofilm agents against the isolated LAB. These findings demonstrate that EA, EB-AuNPs, and EA-AuNPs exhibit significant antibacterial activity against the isolated LAB. Furthermore, EB-AuNPs reduced L. citreum biofilm production, whereas EA-AuNPs inhibited L. mesenteroides and L. brevis biofilm formation. The current results suggest that EB-AuNPs and EA-AuNPs can be used as nanomaterials to inhibit LAB that form biofilms on meat products.

• 한국식품저장유통학회지
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• 제30권2호
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• pp.235-246
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• 2023

Yellowball (Citrus hybrid cv. Yellowball ) is a new citrus hybrid between Haruka (C. tamurana × natsudaidai ) and Kiyomi (C. unshiu × sinensis) and is known to possess strong antioxidant activity. However, detailed information on the antioxidant components of its peel has not yet been reported. This study evaluated the antioxidant activity of the peel and identified the antioxidant components by fractionating a methanolic extract of Yellowball peels using liquid-liquid extraction with n-hexane, ethyl ether (ether), ethyl acetate (EA), butanol, and water. The phenolic contents and antioxidant activities of the n-hexane, ether, and EA fractions were higher than those of the other fractions, and these fractions were further separated by semi-preparative high-performance liquid chromatography (HPLC). Four antioxidant peaks, EA1, EA2, EA3, and He1, were isolated and analyzed using ultra-performance liquid chromatography-quadrupole-time- of-flight mass spectrometry (UPLC-Q-TOF MS). Sinapoyl glucoside and hesperidin were identified in EA2 and EA3, respectively, and a polymethoxylated flavone (PMF) complex (5-hydroxy-3,6,7,8,3',4'-hexamethoxyflavone, natsudaidain, tetrameth- oxyflavone, and tangeretin) was identified in He1. A compound in EA1 with m/z 223.0246 [M-H] could not be identified and was named unknown2. The antioxidant activity of unknown2 (IC₅₀=69.17 ㎍/mL) was similar to that of Trolox, which was noted as a major antioxidant in Yellowball peel. Further studies on the antioxidant capacity of Yellowball peel are required; however, these results provide a foundation for using Yellowball peel as an antioxidant.

• Elastomers and Composites
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• 제24권2호
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• pp.110-121
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• 1989

The radical initiated graft copolymerization of acrylonitrile(AN) and 4-chlorostyrene(4-Clst) onto ethylene-propylene-diene terpolymer(EPDM) rubber was investigated under various conditions. Graft copolymer(AU-EPDM-4-Clst) was isolated b: selective solvent extraction and identified by using IR spectroscopy. The percent grafting is determined as a function of solvent, reaction time, and monomer mole ratio. Percent grafting decreased in the order of tetrahydrofuran(THF)>THF/ethyl acetate(EA)(1 : 1)>cyclohexane/EA(1 : 1)>n-hexane/EA(1 : 1). Grafting increased continuously with increasing the reaction time up to 40 hr, beyond which the grafting levelled off. It was observed that percent grafting increased as increasing [4-Clst]/[AN] mole ratio, but decreased when [4-Clst]/[AN] mole ratio was higher than 1.60. The light resistance of graft copolymer(AN-EPDM-4-Clst) was better than that of ABS.