• Preventive Nutrition and Food Science
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• v.10 no.2
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• pp.118-121
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• 2005

Methanol extracts were prepared from loquat leaves (2 kg) and successively fractionated with hexane, chloroform, ethyl acetate, butanol, and water solvents. The ethyl acetate fraction exhibited the highest antioxidative and, antimicrobial activities. Therefore, the ethyl acetate fraction was purified and a chemical structure was identified by $^1H$ and $^{13}C-NMR$ spectra, FT-IR and EI/MS spectroscopies. The isolated antioxidative and antimicrobial substance was identified as epicatechin.

• Natural Product Sciences
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• v.25 no.3
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• pp.255-260
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• 2019

Piper nigrum L. (Piperaceae), which is a well-known food seasoning, has been used as a traditional medicine for the treatment of vomiting, abdominal pain, diarrhea and anorexia in Korea, China and Japan. Methanol extract from the fruit of P. nigrum was successively partitioned as n-hexane, methylene chloride, ethyl acetate, n-butanol and $H_2O$ soluble fractions. Among those fractions the ethyl acetate soluble fraction showed the most potent DPPH radical scavenging activity, and piperine was isolated from the ethyl acetate fraction. To know the antioxidant activity of piperine, we tested the activities of superoxide dismutase (SOD) and catalase together with oxidative stress tolerance and intracellular ROS level in Caenorhabditis elegans. To investigate whether piperine-mediated increased stress tolerance was due to regulation of stress-response gene, we quantified SOD-3 expression using transgenic strain including CF1553. Consequently, piperine enhanced SOD and catalase activities of C. elegans, and reduced intracellular ROS accumulation in a dose-dependent manner. Moreover, piperine-treated CF1553 worms exhibited significantly higher SOD-3::GFP intensity.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.489-493
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• 2003

This study was to search antioxidant constituents of ethyl acetate extract from Stachys siebodlii MIQ. The test of nitrite scavenging abilities were performed on the extracts of methanol, hexane, chloroform, ethyl acetate, butanol, and water, Ethyl acetate extract, The most promising one was fractionated on a silical gel column using elution solvent(chloroform:methanol:water=70:30:5 lower phase) at a flow rate 1.0ml/min. UV-VIS spectral data of each fraction showed adsorption maxima in the range of $284{\sim}330nm$ which is the characteristic range of $210{\sim}290nm$ and $300{\sim}550nm$ phenolic compounds. These results suggested that Stachys siebodlii MIQ. shows natural antioxidant activity. The nitrite scavenging abilities reached the maxium at pH 1.2 and the ethyl acetate fraction of root showed stronger scavenging ability.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.4
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• pp.621-625
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• 2004

Electron donating abilities, nitrite scavenging effects and antimicrobial activities of various fractions obtained from ethanol extract of Smilax china were examined. Among the fractions investigated, the highest electron donating ability was determined with ethyl acetate fraction showing about 81.0% when reacted for 10 min. However, the lowest ability was found from chloroform fraction. Ethyl acetate and butanol fractions also showed very high nitrite scavenging activity at all concentrations tested. All the fractions revealed antimicrobial activity against Listeria monocytogenes and Staphylococcus aureus, Gram (+) bacteria, at both 2.5% and 5.0% concentrations. However, no antimicrobial activity was observed on Escherichia coli O157:H7 and Salmonella Typhimurium, Gram (-) bacteria, at 2.5%, but very low activity was detected by 5.0% concentration of ethanol extract, ethyl acetate and water fractions.

• Korean Journal of Food Science and Technology
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• v.52 no.4
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• pp.350-356
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• 2020

This study was conducted to investigate the antioxidant compounds and activities of Prunus yedoensis Matsumura bark (PYMB) ethanol extracts (EE) and various other fractions. Among them, the highest total phenol content was 496.80 mg gallic acid equivalent/g in the ethyl acetate fractions (EAF). The flavonoid contents were 7.26-265.52 rutin equivalent mg/g, with the EAF showing the highest levels. The highest proanthocyanidin content was determined to be 326.31 catechin equivalent mg/g in the EAF and the remaining values in descending order were as follows: n-butanol, ethanol, dichloromethane, water, and n-hexane. EAF exhibited the highest DPPH, ABTS⁺, superoxide^- radical scavenging activities, and reducing power, whereas the nitrite scavenging activities were the highest in the case of the EE. The n-hexane and water fraction antioxidant compounds and activities were lower than those of the other fractions. In summary, these results suggest that the PYMB EAF is a potential source of natural antioxidants.

• Korean Journal of Food Science and Technology
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• v.26 no.5
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• pp.622-626
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• 1994

Propolis was extracted by several organic solvents, and the antioxidative effect of the extracts on palm oil and lard was tested with the extract solely or combined with some synergists, using the Rancimat Method. The extraction yields of propolis by each solvent were 68.1% (75% ethanol), 75.5% (99% ethanol), 67.4% (methanol;, 86.7% (chloroform), 72.6% (ethyl acetate) and 65.6% (butanol). AI (Antioxidative Index; induction p-eriod of oil containing antioxidant/induction period of natural oil) of the methanol extract was highest, and more effective on lard than palm oil. The ethyl acetate fraction of 75% ethanol extract showed higher antioxidative effect than 75% ethanol extract, and obtained the highest antioxidative effect on palm oil with ascorbic acid as synergist and lard with ${\dalta}-toocopherol$.

• ALGAE
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• v.24 no.3
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• pp.179-184
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• 2009

Methanol crude extract of the sea grass Zostera marina L. and organic solvent fractions (n-hexane, chloroform, ethyl acetate, n-butanol, and water) were screened for antioxidant activity (total phenolic contents, DPPH scavenging activity, and reducing power) and antimicrobial activity against three human skin pathogens, two bacteria and a yeast; Staphylococcus aureus, Staphylococcus epidermidis, and Candida albicans. Total phenolic contents and 2, 2- diphenyl-1-picrylhydrazyl (DPPH) scavenging activity were highest in the ethyl acetate fraction with 968.50 $\mu$g gallic acid equivalent per milligram of extract, and ca. 95% scavenging activity on the DPPH radicals at 10 mg $ml^{-1}$. In antimicrobial activity tests, MICs (Minimum Inhibitory Concentration) of each Zostera marina extract partitioned ranged from 1mg to 8 mg $ml^{-1}$ (extract/ 10% DMSO) against all three human skin pathogens. The MICs of the ethyl acetate and n-butanol fractions were the same with 1 mg $ml^{-1}$ against S. aureus and C. albicans. The ethyl acetate fraction of Z. marina does protect against free radicals and may be used to inhibit the growth of human skin pathogens.

• KSBB Journal
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• v.19 no.3
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• pp.187-191
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• 2004

Among 14 medicinal plants selected for the study ethanol (70%) extract of Coptis japonica Makino showed the highest anti-microbial activity against Helicobacter pylori followed by Perilla frutescens var. acuta KUDO, Caesalpinia sappan L. and Schizonepeta tenuifolia Briq. However, anti-urease activity of methanol (80％) extracts was best for Forsythiae Fructus followed by Caesaipinia sappan L. and Schizonepeta tenuifolia Briq. In the second fractionation using water, ethyl acetate and butanol more than 90％ of the anti-urease activity was detected in the ethyl acetate fraction.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.36 no.3
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• pp.175-182
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• 2010

In this study, the antioxidative effects, inhibitory effects on tyrosinase of Cedrela sinensis extracts were investigated. The ethyl acetate fraction of extract ($3.54\;{\mu}g/mL$) and aglycone fraction of extract ($2.15\;{\mu}g/mL$) showed more excellent free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity ($FSC_{50}$) than the activity of (+)-$\alpha$-tocopherol ($8.98\;{\mu}g/mL$). Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) of Cedrela sinensis extracts on ROS generated in $Fe^{3+}$-EDTA/$H_2O_2$ system were investigated using the luminol-dependent chemiluminescence assay. The ethyl acetate fraction of extract ($0.15\;{\mu}g/mL$) and aglycone fraction of extract ($0.12\;{\mu}g/mL$) showed 10 times more excellent ROS scavenging activity than activity of L-ascorbic acid ($1.50\;{\mu}g/mL$). The protective effects of fractions of Cedrela sinensis on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The ethyl acetate fraction of extract and aglycone fraction of extracts suppressed photohemolysis in a concentration dependent manner ($5{\sim}25\;{\mu}g/mL$). The inhibitory effect of Cedrela sinensis extracts on tyrosinase was investigated to assess their whitening efficacy. Inhibitory effects ($IC_{50}$) on tyrosinase were determined with ethyl acetate fraction of Cedrela sinensis extract ($48.00\;{\mu}g/mL$) and aglycone fraction of extract ($5.88\;{\mu}g/mL$). The aglycone fraction showed 40 times more remarkable tyrosinase inhibitory effect than whitening agent, arbutin ($226.88\;{\mu}g/mL$) These results indicate that fractions of Cedrela sinensis can be used as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging $^1O_2$ and other ROS, and protect cellular membranes against ROS. The fractions of Cedrela sinensis can be applicable to new functional cosmetics for antioxidant and whitening.

• Journal of Plant Biotechnology
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• v.45 no.3
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• pp.279-286
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• 2018

Citrus grandis Osbeck pericarp is used as tea, herbal medicine, etc., but is not commercialized in various ways. So, in this study, we identified potential for use of Citrus grandis Osbeck as health functional foods, cosmetics and food preservatives. Methanol extract of Citrus grandis Osbeck pericarp was fractionated with hexane, dichloromethane, ethyl acetate and butanol, to quantitatively analyze total phenol and flavonoid, and investigate antioxidative and enzyme inhibitory activities. Total phenol and flavonoid contents were highest in ethyl acetate fraction, FRAP and ORAC results also revealed highest activity in proportion to total phenol content. DPPH radical scavenging activity revealed that ethyl acetate, butanol and dichloromethane fraction manifested highest activity without significant difference. However, dichloromethane fraction revealed higher TEAC value and tyrosinase inhibitory activity than ethyl acetate fraction, and hexane fraction manifested best results with superoxide radical scavenging activity and ${\alpha}-glucosidase$ inhibitory activity. Antimicrobial activity also revealed best effect in dichloromethane and hexane fractions. So, based on the following results, use of dichloromethane fraction as material of natural functional cosmetics, ethyl acetate fraction for health functional foods, and hexane fractions for pharmaceuticals and food preservatives, would be most practical for product development.