• Preventive Nutrition and Food Science
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• v.10 no.4
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• pp.326-332
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• 2005

A methanol extract of mulberry cake prepared from mulberry fruits (Morus spp.) was shown to have strong scavenging activities against DPPH, superoxide and hydroxyl radicals. Eleven phenolic compounds were isolated from the mulberry cake by a combination of Diaion HP-20, silica gel (or polyamide), Sephadex LH-20 column chromatographies, preparative HPLC and TLC. Their chemical structures were characterized as procatechuic acid (PCA), caffeic acid (CA), cyanidin 3-O-$\beta$-D-glucopyranoside (CyG) and cyanidin $3-O-\beta­D-rutinoside$ (CyR), rutin (RT), isoquercitrin (IQT), astragalin (AG), quercetin (QT), morin (MR), di-hydroquercetin (DHQ), and 4-prenylmoracin (PM) by spectral analysis and the published data. Most of the phenolic constituents were effective scavengers of DPPH, superoxide and hydroxyl radicals, and especially caffeic acid and 4-prenylmoracin showed potent superoxide and hydroxyl radical scavenging activity, in which their activities were higher than that of the well-known antioxidant, BHT (p< 0.05). Dehydroquercetin and quercetin also exhibited strong superoxide and hydroxyl radical scavenging activities. These results suggest that mulberry cake containing antioxidant phenolic compounds may be useful as natural antioxidants in functional foods and cosmetics.

• Journal of Korea Foresty Energy
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• v.22 no.3
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• pp.11-19
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• 2003

Allelopathic effects of black locust(Robinia pseudoacacia L.) was evaluated through germination tests using 13 different species including R. pseudoacacia itself. The water extract from leaf or root of R. pseudoacacia was separately tested. Seed germination of several species was inhibited in the presence of leaf or root extract, although the level of germination was in a wide range depending on the species. Seed germination of R. pseudoacacia was suppressed by 30 % in its leaf extract. Among tested tree species, Hibiscus syriacus and Alnus frma showed significantly inhibited germination in the root extracts whereas Thuja orientalis exhibited germination inhibition in the leaf extract. HPLC was carried out to identify allelochemicals in extracts of leaf and root using eight authentic phenolic compounds that are known to be responsible for allelopathy. The major phenolic compounds occupying about 40 % of total phenolic acids were gentisic acid in leaves and vanillic acid and syringic acid in roots. The leaves contained 7 times more phenolic acids than the roots. Among 8 tested phenolic compounds vanillin was detected only in roots and coumaric acid in leaves. Consequently, 3 out of 13 species showed significantly inhibited germination due to leaf or root extract. This germination test indicates that the inhibitory allelopathic effect by R. pseudoacacia is caused by chemical interaction not by nutritional competition and that the allelochermicals of black locust act species-specifically. No specific influence of the total amount of phenolic compounds on the allelopathic inhibitory germination and the synergic effect by each phenolic compound may play a role for the allelopathic effect by R. pseudoacacia.

• Journal of the Korean Wood Science and Technology
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• v.37 no.2
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• pp.164-170
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• 2009

The bark of Acer barbinerve was extracted with 70% aqueous acetone and the organic extracts were concentrated to small volume using rotary evaporator and then fractionated successively with n-hexane, dichloromethane, ethyl acetate and water. The chromatographic separation of ethyl acetate soluble fraction led to the isolation of five phenolic compounds. By means of spectroscopic method, the structures of these compounds were identified to methyl gallate (1), methyl gallate-4-O-${\beta}$-D-glucose (2), (+)-catechin (3), (-)-epicatechin (4) and (-)-epicatechin-3-O-gallate (5). These compounds (1-5) have not been reported in this plant yet.

• Korean Journal of Pharmacognosy
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• v.41 no.4
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• pp.308-312
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• 2010

The purpose of this research is to provide basic informations to discriminate between sea buckthorn (Hippophae rhamnoides) cultivated in the Republic of Korea and Mongolia. The phenolic compounds of sea buckthorn, were measured by the HPLC analysis. Catechin, rutin, quercetin, isorhamnetin were found in methanol extracts of sea buckthorn. Total phenolic compound of Korean sea buckthorn leaves (1.852%) was about five times higher than those of Mongolian sea buckthorn berries (0.338%). As a result, the order of the total phenolic compound and Catechin content was 1) sea buckthorn leaves, 2) sea buckthorn stems, 3) sea buckthorn roots, and 4) sea buckthorn berries. Statistically no big differences in levels of phenolic compounds were consistently found in sea buckthorn cultivated in the Republic of Korea and Mongolia investigated in this work.

• Analytical Science and Technology
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• v.14 no.5
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• pp.377-383
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• 2001

Total amounts of phenolic compounds of Korean apples were determined by UV-visible spectrphotometry of Folin-Dennis, Prussian-blue and vanillin-HCI, respectively. The analytical data from the method of Folin-Dennis were estimated to be the most reasonable to determine the total amounts of phenolic compounds in Korean apples. It was also confirmed that the amounts of total phenolics could be calculated as chlorogenic acid equivalence, more effectively than that of other phenolic compound equivalence.

• Korean Journal of Pharmacognosy
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• v.45 no.2
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• pp.141-146
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• 2014

In this study, we investigated on antioxidative activities and tyrosinase inhibitory activities of methanol extract and its fractions from roots of Arctium lappa. The total phenolic compound and flavonoid content of the ethylacetate fraction was found to be 818.29 mg/g and 360.59 mg/g as the highest content. In the measurement of DPPH radical scavenging ability and tyrosinase inhibitory activity, the ethylacetate fraction was higher than the other fractions and the extract. In addition, comparative analysis of phenolic compounds by liquid chromatography-mass spectrometry (MS)/MS system under the multiple-reaction monitoring (MRM) with negative-ion electrospray ionization mode. The main phenolic compounds in the extract and fractions of roots from Arctium lappa were cynarin and chlorogenic acid. The main phenolic compound of the ethylacetate fraction was cynarin. n-Butanol fraction had a significantly higher chlorogenic acid content than other samples. In conclusion, DPPH radical scavenging ability and tyrosinase inhibitory activity of the cynarin-riched ethylacetate fraction showed the highest activity.

• Preventive Nutrition and Food Science
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• v.6 no.2
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• pp.107-111
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• 2001

Physical and chemical characteristics of four white-and one yellow-fleshed peach cultivars were compared at optimum maturity stage. In addition, differences of phenolic composition, polyphenol oxidase (PPO) activities and PPO isozyme patterns in two peach types were also investigated. There are no significant differences in firmness and color values between two peach types, except for "Yumyung", a white-fleshed peach with the highest firmness, and "Hwangdo", a yellow-fleshed peach with the highest yellowness (b)* value. In general, the soluble solid/titratable acidity ratios, ascorbic acid and total phenolic contents were significantly higher for white-fleshed peaches than those for yellow-fleshed peach (p<0.05). Three major phenolic compounds, catechin, neochlorogenic acid and chlorogenic acid, were found in both the white-and yellow-fleshed peaches. Among them, catechin was the predominant phenolic compound in the white-fleshed peaches, followed by neochlorogenic acid, and chlorogenic acid. Meanwhile, neochlorogenic acid was present in the highest level of the yellow-fleshed peach, but levels of two other phenolic compounds were lower. PPO activities of the white-fleshed peaches were generally higher than that of the yellow-fleshed peach, with the one major band and two minor bands, and there were no big differences in PPO isozyme patterns between two different peach cultivars.

• Food Science and Preservation
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• v.14 no.1
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• pp.73-77
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• 2007

The physiochemical properties of Rhododendron mucronulatum pollens were examined after the use of various extraction conditions. The levels of phenolic compounds and electron donating abilities (DPPH) were better after 80% (v/v) ethanol extraction than after water extraction. The content of phenolic compounds and the DPPH were high when the solvent ratio was 20X. The content of phenolic compounds was highest at $45^{\circ}C$ (347.60 mg/100 g). The DPPH was highest, at 67.93%, when extraction was performed at $25^{\circ}C$. An extraction time of 6 hr yielded the highest content of phenolic compounds (312.63 mg/100 g). The DPPH did not vary with extraction time. Both the levels of phenolic compounds and DPPH values rose when extractions were performed twice. In summary, a solvent ratio of 20X, an extraction temperature of $25-45^{\circ}C$, double extraction and an extraction time of 6 hare optimal for extraction, with maximal DPPH and phenolic content, of Jindalrae pollens.

• Food Science and Biotechnology
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• v.16 no.1
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• pp.90-98
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• 2007

The antioxidant activities of water ($H_2O$) and ethanol (EtOH) extracts from hamcho (Salicornia herbacea L.) juice and cake prepared by enzymatic treatments were evaluated by in vitro assays against DPPH, superoxide, and hydroxyl radicals. Among the $H_2O$ and EtOH extracts from five different carbohydrases treated, the EtOH extract from viscozyme-treated hamcho cake had higher yield and phenolic content, and exhibited the strongest radical scavenging activity against DPPH ($IC_{50}=186.91\;{\mu}g/mL$), superoxide ($IC_{50}=87.54\;{\mu}g/mL$), and hydroxyl radicals ($IC_{50}=367.07\;{\mu}g/mL$). Antioxidant assay-guided fractionation and purification of the EtOH extract led to isolation and identification of five phenolic compounds, procatechuic, ferulic and caffeic acids, quercetin, and isorhamnetin. Most of these phenolic compounds exhibited considerable DPPH, superoxide, and hydroxyl radical scavenging activities, and in particular, caffeic and ferulic acids had stronger superoxide and hydroxyl radical scavenging activities than the well-known antioxidant radical scavenger, (+)-catechin (p<0.05). Quercetin and isorhamnetin were the primary compounds responsible for the strong antioxidant activity in the EtOH extract of the viscozyme-treated hamcho cake. Meanwhile, these five phenolic compounds were detected in the EtOH extract of the viscozyme-treated hamcho cake at the following levels (dry base of hamcho); procatechuic acid (1.54 mg%), caffeic acid (6.87 mg%), ferulic acid (8.45 mg%), quercetin (12.63 mg%), and isorhamnetin (6.65 mg%). However, three of these phenolic compounds (procatechuic, caffeic acid, and ferulic acids) were detectable in the $H_2O$ extract of viscozyme-treated hamcho juice. These results suggest that the EtOH extract of viscozyme-treated hamcho cake may be a potential source of natural antioxidants.

• Korean Journal of Weed Science
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• v.30 no.4
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• pp.396-404
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• 2010

Phenolic compounds, which are products of secondary metabolism, have been demonstrated to be widespread growth substances in plants. The objectives of this study were to identify the phenolic compounds in common ragweed (Ambrosia artemisiifolia var. elatior) by HPLC and to evaluate their effects on germination and seedling growth of three weed species. Under controlled conditions in Petri dishes at $25^{\circ}C$, $10^{-3}$ and $10^{-4}$ M solutions of phenolic compounds were evaluated in seed germination tests. Four phenolic compounds (caffeic acid, O-coumaric acid, ${\rho}$-coumaric acid and ferulic acid) in common ragweed plant were identified and their concentration was increased from the stage before flowering through full flowering stage. Treatment of O- and ${\rho}$-coumaric acids delayed the seed germination of Digitalia ciliaris, while the treatment of caffeic acid delayed the seed germination of Echinochloa crus-galli. In time to 50% germination ($T_{50}$), phenolic compounds at $10^{-4}$ M promoted in Cyperus microiria and E. crus-galli but the level of $10^{-3}$ M delayed the $T_{50}$ of those weeds. The O-coumaric acid inhibited seed germination and seedling growth of the tested weeds and especially it perfectly inhibited the root growth of E. crus-galli.