• Plant Resources
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• v.8 no.2
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• pp.103-109
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• 2005

Lettuce (Lactuca sativa L.) is known to contain water-soluble substances that improve antioxidant status due to the richness in antioxidants. Greenhouse experiment was carried out under different shading conditions during spring lettuce growing season. Shade significantly reduced shoot weight, number of leaves and chlorophyll content, while it increased shoot length of lettuce plants. The antioxidant potential of the individual fraction was in order of n-butanol > ethyl acetate > water > n-hexane fraction, although was less than that of commonly used antioxidants, BHT and ascorbic acid. Fractions from lettuce plants dose-dependently increased DPPH free radical scavenging activity, in vitro test. By means of HPLC analysis, BuOH fraction of cultivar 'Hwahyang' (57.93 mg $100g^{-1}$) had the highest amount of antioxidant chi orogenic acid. Shading treatment increased average amount of chlorogenic acid of all cultivars in BuoH, EtOAc, hexane and water fractions by 33, 120, 144, and $58\%$, respectively. These results suggest that lettuce plants had potent antioxidant activity, and their activities were differently exhibited depending on cultivar and fraction.

• Korean Journal of Pharmacognosy
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• v.35 no.3 s.138
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• pp.207-214
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• 2004

This study was investigated antioxidatve activity for the purpose of developing antioxidant from Morus bombycis Koidzumi. Antioxidant activities of four different organs of Morus bombycis Koidzumi such as fruit, leaf, stem, and root were examined by radical scavenging effect with 1,1-diphenyl-2-picrylhydrazyl (DPPH). 80% methanol extract from the stem showed strongly antioxidative activity and 80% Ethanol extracts from the root, stem, and fruit had high antioxidative activity among 24 samples tested. The 80% ethanol extract has strong absorbency at UVA region (350 nm). The ethyl acetate (EtOAc) fraction exhibited antioxidative activity with $IC_{50}$ of $15.0\;{\mu}g/ml$ similar to those of synthetic antioxidant, BHT The EtOAc fraction has a good absorbency property as synthetic filter. In the absorbance of various extracts, the 80% ethanol and ethyl acetate extracts from the root of Morus bombycis Koidzumi showed higher absorbancy at 285 nm. The ethyl acetate fraction from the root of Morus bombycis Koidzumi contained total phenolic compounds of 654.8 mg/100 g. These results indicate that phenolic compounds are the major was biological components in the root of morus bombycis Koidzumi extracts. Considering these biological activities, the extracts of Morus bombycis Koidzumi showed a possibility to be used as a new material for natural anti-oxidants and substitutes for synthetic UV sunscreen agents.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.898-904
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• 2002

The ehtyl acetate-soluble acidic fractions from juice and cake of Rubrs coreanum fruit showed DPPH radical-scavenging activity. Each fraction was purified through silica gel adsorption column chromatography. The compounds in the ethyl acetate-soluble acidic fraction of juice were identified as 4-hydroxybenzoic acid, 4-hydroxy-3-methoxybenzoic acid, 3,4-dihydroxybenzoic acid, 3,4,5-trihydroxybenzoic acid, and 3,4-dihydroxycinnamic acid by GC-MS. The compounds in the ethyl acetate-soluble acidic fraction of cake were also identified as succinic acid, 3,4-dihydroxybenzoic acid, citric acid, 3,4,5,-trihydroxybenzoic acid, and 3,4-dihydroxycinnamic acid by GC-MS. Antioxidative activity of the identified compounds were evaluated by DPPH radical-scavenging assay and hydroxyl radical-scavenging activity assay.

• The Korean Journal of Food And Nutrition
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• v.30 no.6
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• pp.1364-1369
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• 2017

There is a growing demand for natural sleep aids due to various side effects of long-term administration of pharmacological treatments for insomnia. Honey has been reported to exhibit numerous potential health benefits, and it is hypothesized that honey may favorably affect insomnia treatment. Therefore, this study was performed to investigate the possible hypnotic effect of clover honey (CH) and to determine its in vivo mechanism. The total flavonoid content (TFC) of CH and fractions extracted with ethylacetate (EtOAc) and $H_2O$ was measured. The pentobarbital-induced sleep test using $GABA_A$-benzodiazepine (BZD) agonists and antagonists was conducted to evaluate the potential mechanism of action behind the sedative-hypnotic activity of CH in mice. The results showed that administration of 500 and 1,000 mg/kg of CH significantly (p<0.01) reduced the sleep latency to a level similar to that of diazepam (DZP, 2 mg/kg), and 1,000 mg/kg of CH significantly (p<0.01) prolonged the sleep duration, which was comparable to that of DZP (2 mg/kg). Administration of the EtOAc fraction with a higher TFC significantly reduced the sleep latency at 50 to 200 mg/kg and prolonged the sleep duration at 100 to 200 mg/kg, which were comparable to those after administration of DZP (2 mg/kg). However, co-administration of CH and EtOAc with flumazenil, a specific $GABA_A-BZD$ receptor antagonist, blocked the hypnotic effect. Our findings suggest that the hypnotic activity of CH may be attributed to allosteric modulation of $GABA_A-BZD$ receptors. The TFC of CH is expected to be a key factor that contributes to its hypnotic effect.

• Food Science and Preservation
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• v.18 no.1
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• pp.53-58
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• 2011

Activity-guided isolation from an ethylacetate-soluble fraction of a 70% (v/v) ethanolic extract from the roots of Taraxacum ohwianum, using a pancreatic lipase inhibition assay, resulted in isolation and identification of five phenolic metabolites of previously known structure; these were 3,5-di-O-caffeoylquinic acid, chicoric acid, caffeic acid, protocatechuic aldehyde, and luteolin. All structures were confirmed by NMR and MS scpectroscopic data. Of these compounds 3,5-di-O-caffeoylquinic acid exhibited the most potent inhibitory activity, with $IC_{50}$ of $65.1{\pm}0.7\;{\mu}M$ against pancreatic lipase.

• Korean Journal of Food Science and Technology
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• v.37 no.4
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• pp.656-659
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• 2005

Hot water extracts of Angelica keiskei aerial parts were solvent-fractionated with ethyl acetate (EtOAc) and buffers (5% $NaHCO_3$, pH 8.0; 1.0 N HCl, pH 3.0) to obtain EtOAc-soluble acidic and neutral fractions. EtOAc-soluble neutral fraction was purified by Sephadex LH-20 column chromatography and reverse phase HPLC. Assay for purification of antioxidative compounds was performed by spraying DPPH solution on thin layer chromatography. Two isolated substances were identified as pseudoisopsoralen and 8-methoxypsoralen(xanthotoxin) by FAB-MS and NMR analyses.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.3
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• pp.293-299
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• 2023

Acne vulgaris is often associated with acne-related bacteria such as Cutibacterium acnes. In this study, we investigated the antibacterial effects of the methanol extract of the algae Ecklonia cava and its solvent-soluble extract against C. acnes. Among five solvent fractions, the ethyl acetate (EtOAc) fraction exhibited the strongest antibacterial activity against C. acnes. Furthermore, the EtOAc-soluble extract exhibited the highest total phenolic contents among the five solvent fractions tested. The EtOAc subfraction 07 (Fr. 07) extract showed the highest antibacterial effect against C. acnes and isolated C. acnes along with minimum inhibitory concentration (MIC) ranging from 32 to 64 ㎍/mL. Additionally, MICs of antibiotics against antibiotic-resistant C. acnes strains were substantially reduced when antibiotics were combined with Fr. 07, suggesting that Fr. 07 restore the antibacterial activity of the antibiotics. The fractional inhibitory concentration indices clearly revealed an additive synergistic effect of Fr. 07 with antibiotics. The results of the present study suggest a potential role for E. cava in the control of infections related to acne vulgaris.

• Journal of Life Science
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• v.24 no.11
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• pp.1157-1167
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• 2014

In order to compare the anti-inflammatory effects of five selected cereal grains-proso millet, hwanggeumchal sorghum, foxtail millet, barnyard millet, and adlay-the inhibitory activities of 80% ethanol (EtOH) extracts obtained from the individual grains on lipopolysaccharide (LPS)-induced nitric oxide (NO) generation were investigated in RAW264.7 cells. The EtOH extract of barnyard millet (Echinochloa crus-galli var. frumentacea) grains exhibited more potent anti-inflammatory activity than that of the other grains. When the EtOH extract of barnyard millet grains was sequentially fractionated with n-hexane, methylene chloride (MC), ethyl acetate (EtOAc), and n-butanol, the majority of the anti-inflammatory activity was detected in the MC fraction, followed by the EtOAc fraction. Pretreatment with the MC fraction caused downregulation of the expression levels of iNOS- and COX-2-specific transcripts and proteins, as well as proinflammatory cytokine gene transcripts (IL-$1{\beta}$, IL-6, and TNF-${\alpha}$) in LPS-stimulated RAW264.7 cells. Additionally, the MC fraction could suppress not only the LPS-induced nuclear translocation of cytosolic NF-kB, but also the LPS-induced activation of MAPKs, such as ERK, JNK, and p38MAPK. Further analysis of the MC fraction by HPLC identified kaempferol, biochanin A, and formononetin as the major phenolic components. Both kaempferol and biochanin A, but not formononetin, could exert anti-inflammatory effect at the same concentrations as those of the MC fraction. Consequently, these results indicate that kaempferol and biochanin A are among the most effective anti-inflammatory phenolic components in barnyard millet grains. This finding suggests that barnyard millet grains and the MC extract enriched in kaempferol and biochanin A could be beneficial functional food sources that have an anti-inflammatory effect.

• Natural Product Sciences
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• v.11 no.1
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• pp.10-12
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• 2005

Flavonol galactosides were isolated from the EtOAc fraction of Artemisia apiacea by repeated column chromatography. Their structures were elucidated as $isorhamnetin-3-O-{\beta}-D-galactoside$ (1) and $quercetin-3-O-{\beta}-D-galactoside$ (2) by chemical and spectroscopic analysis. This is the first report on the isolation of compound 2 from this plant.

• Korean Journal of Pharmacognosy
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• v.30 no.4
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• pp.420-422
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• 1999

From the EtOAc fraction of Dipsacus asper, four compounds have been isolated. On the basis of spectral data, these compounds were identified as protocatechuic acid, caffeic acid, 3,4-di-O-caffeoyl quinic acid and methyl 3,4-di-O-caffeoyl quinate.