• Journal of Applied Biological Chemistry
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• v.48 no.3
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• pp.144-147
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• 2005

DPPH and ABTS radical scavenging, and tyrosinase inhibitory activities of bioactive compounds 1-4 isolated from Cedrela sinensis leaf were assessed. Structures of isolated compounds were established by UV, one- and two-dimensional NMRs, and mass spectroscopic methods.

• Korean Journal of Plant Resources
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• v.31 no.4
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• pp.322-329
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• 2018

A diarylheptanoid, (5S)-1,7-bis-(3,4-dihydroxyphenyl)-5-hydroxyheptane-3-one-5-O-${\beta}$-D-xylopyranoside, named oregonin (1), was isolated from the of Alnus japonica (A. japonica), which is a species of the genus Betulaceae, growing throughout Korea, Japan and China. The structure was elucidated by various spectroscopic methods including negative and positive LC/MS, 1H-NMR, and 13C-NMR techniques or by comparison with authentic samples. In order to evaluate the anti-oxidative activities of oregonin (1) isolated from A. japonica, 1,1-diphenyl-2-picryhydrazyl (DPPH) radical scavenging activity and 2,2'-azino-bis[3-ethylbenzothiazoline-6-sulphonic acid] (ABTS) radical scavenging activity were measured in vitro. Oregonin from A. japonica exhibited potent DPPH and ABTS radical scavenging activities. A. japonica shows not only 1,1-diphenyl-2-picryhydrazyl (DPPH) radical scavenging activity and ABTS radical scavenging activity, but also apoptosis modulative effects. The present results indicate that A. japonica could be a hair-growth-promoting agent for cosmetic products.

• Journal of the Korean Applied Science and Technology
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• v.37 no.6
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• pp.1583-1590
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• 2020

In this study, activity of anti-oxidation of Cinnamomum loureiroi extract (CLE). In order to measure anti-oxidation effect of CLE, phenol content of CLE, radical scavenging activity of ABTS and DPPH, and decrease of ROS production. Before the experiment, against Raw 264.7 cell, a cytotoxicity was measured and the result showed no toxicity. CLE's total polyphenol amount was 397.7±8.3 mg/g and the total flavonoid amount was 101.899±0.885 mg/g. As a measurement result of ABTS radical scavenging ability and DPPH radical scavenging ability, radical scavenging ability increased depends on the concentration. CLE's effect on the ROS creation was checked and the result showed that CLE suppressed ROS creation by showing a meaningful decrease of ROS generation. From all of the results, CLE is know to have an antioxidant effect. These results will be provided as fundamental data for further development of the new material of functional cosmetics to the results above.

• The Korean Journal of Community Living Science
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• v.21 no.4
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• pp.641-649
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• 2010

To make sure of the usefulness of extract of Rubus coreanus Miquel for producing functional feeding honey, we compared some antioxidative indicators of feeding honey using extract of Rubus coreanus Miquel with acacia honey, SueBee Clover honey(USA), feeding honey on the market. The water content of four honeys were 16.6~26.5%, pH were 3.18~3.70, and titratable acidity ranged 0.018~0.022%. The phenolic compound contents of SueBee Clover honey and feeding honey using extract of Rubus coreanus Miquel were 8.3 mg/100 g and 7.3 mg/100 g, respectively, and were significaltly higher thgheacacia honey and feeding honey on the market. The flavonoid contents per 100 g of honey ranged from 2.3 mg(acacia honey) to 15.0 mg(SueBee Clover honey). DPPH anion scavenging activity of four honeys were not high. 0.5~2.0 g/ml of feeding honey using extract of Rubus coreanus Miquel was 16~36% and showed a concentration-reliant figure. At the concentration of 0.25~0.75 mg/ml, the reducing power of four honeys increased concentration-dependently, and the power of 0.25 mg/ml of feeding honey using extract of Rubus coreanus Miquel was corresponding to thgt of $150{\mu}g$/ml of a vitamin C solution. ABTS radical scavenging activity of feeding honey using extract of Rubus coreanus Miquel was 43.3~68.4%; the highest activity amongst all samples. When plotting the dose-response curve, ABTS radical scavenging activity also increased as their concentration increased from 62.5 mg/ml to 500 mg/ml. The heat treatment reduced the phenolic compound contents of acacia honey and feeding honey using extract of Rubus coreanus DPPH anion scavenging activity of feeding honey on the market and feeding honey using extract of Rubus coreanus Miquel did not changed significaltly after heating for 20 min, and the three honey except SueBee Clover honey maintained the reducing power with the same treatment.

• The Korean Journal of Food And Nutrition
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• v.33 no.4
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• pp.372-380
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• 2020

The purpose of this study is to investigate the physicochemical properties of jelly made from fermented red ginseng concentrate (FRGC) that can be easily absorbed and digested for the health promotion of the elderly. The pH of the jellies tended to decrease with increasing concentration of FRGC. Soluble solid content has significantly higher value when added more than 2%, and the water content of the sample was significantly lower when the FRGC was added 4%. As the amount of FRGC was increased, the total color difference increased, and the hardness of samples decreased significantly. On the other hand, the total ginsenoside contents of the FRGC was 45.50 mg/g. As the concentration of FRGC increased, the content of polyphenol and flavonoids increased. The increasing pattern of polyphenols and flavonoids showed a similar trend. As the content of FRGC increased, ABTS free radical scavenging activity significantly increased (p<0.05), and in the control, the minimum value (62.6 AEAC) and the 4% sample were highest (116.2 AEAC). DPPH radical scavenging activity was like that of ABTS radical scavenging activity. However, there was no significant difference in DPPH radical scavenging activity of 3% and 4% red ginseng jelly.

• Preventive Nutrition and Food Science
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• v.21 no.4
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• pp.355-360
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• 2016

The influence of extraction temperature, powder concentration, and extraction time on the antioxidant properties of aqueous ginger extract was investigated. The possibility of estimating the antioxidant properties of the extract from its absorbance and colour properties was also investigated. Results indicated that powder concentration was the most significant factor to consider in optimizing antioxidant extraction. However, temperature and time still influenced the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity while extraction temperature influenced the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of the extract. Using the total phenol content, total flavonoid content, ABTS radical scavenging activity, and DPPH radical scavenging activity of the extract, the multiresponse optimization condition for extraction of antioxidant based on the experimental range studied is $96^{\circ}C$, 2.10 g/100 mL, and 90 min. The absorbance of the ginger extract at 610 nm could be exploited for rapid estimation of its total flavonoid and polyphenol with a $R^2$ of 0.713 and 0.753, respectively.

• Korean Journal of Agricultural Science
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• v.50 no.3
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• pp.527-538
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• 2023

The aim of this study was to investigate the antioxidant effects of O. robusta stem extract (ORE) and to determine the total polyphenol and flavonoid contents. Free radical scavenging properties were evaluated using DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid)), and ·OH (hydroxyl radical) scavenging assays. Total polyphenol and flavonoid contents were measured using Folin-Ciocalteu reagent and aluminum chloride colorimetric methods, respectively. Active compounds of ORE were determined using high-performance liquid chromatography (HPLC). The results of the study showed that ORE exhibited DPPH, ABTS, and ·OH radical scavenging activities in a dose-dependent manner. Especially, 1,000 ㎍/mL of ORE showed the strongest radical scavenging properties against DPPH, ABTS, and ·OH. ORE contained total polyphenol content of 57.4 mg GAE/g and total flavonoid content of 5.4 mg QE/g, which may contribute to their antioxidant effects. As a result of HPLC, the contents of active compounds in ORE, dihydrokaempferol (0.65 ㎍/mL), and 3-O-methylquercetin (1.10 ㎍/mL) were confirmed. In conclusion, ORE may be useful as a functional material with antioxidant properties.

• Journal of the Korean Society of Food Culture
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• v.30 no.2
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• pp.220-226
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• 2015

This study was to conducted to investigate the antioxidative activity of 70% ethanol extracts of kiwi of three different colors (gold, green and red) by measuring DPPH, ABTS radical scavenging activity, tyrosinase inhibitory effect, metal chelating effect, reducing power, and nitrite scavenging activity. Total polyphenol contents were: gold kiwi, 3.09 mg GAE/g, green kiwi 2.71 mg GAE/g, and red kiwi 4.59 mg GAE/g, respectively. Red kiwi showed higher antioxdidant activity than gold and green kiwi. DPPH and ABTS radical scavenging activity, and nitrite scavenging activity of red kiwi exhibited 94.83, 99.57, and 97.88%, respectively, at a concentration of 20 mg/mL, which were equal to those of ascorbic acid (positive control). Metal chelating effect of red kiwi was superior to that of ascorbic acid. Therefore, the availability of red kiwi will be increased in the field of functional material for food additives and value added products.

• Food Science and Biotechnology
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• v.18 no.4
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• pp.1051-1054
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• 2009

This study was conducted to investigate the antioxidant activity of the extracts of lotus (Nelumbo nucifera Gaertner). The total phenolic contents in leaf, stem, and root were 165, 74, and 30 tannic acid equivalent mg/g of dried extract or fraction respectively. The butanol and ethylacetate fractions of lotus parts showed higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity than other fractions. 2,2'-Azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation radical scavenging activity also showed the similar result as the DPPH radical scavenging activity. The antioxidative capacity of the ethylacetate fraction was the highest among fractions and its fraction showed higher contents of total polyphenol.

• Food Science of Animal Resources
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• v.34 no.3
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• pp.362-371
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• 2014

This study utilized commercially available proteolytic enzymes to prepare egg-white protein hydrolysates (EPHs) with different degrees of hydrolysis. The antioxidant effect and functionalities of the resultant products were then investigated. Treatment with Neutrase yielded the most ${\alpha}$-amino groups (6.52 mg/mL). Alcalase, Flavourzyme, Protamex, and Ficin showed similar degrees of ${\alpha}$-amino group liberation (3.19-3.62 mg/mL). Neutrase treatment also resulted in the highest degree of hydrolysis (23.4%). Alcalase and Ficin treatment resulted in similar degrees of hydrolysis. All hydrolysates, except for the Flavourzyme hydrolysate, had greater radical scavenging activity than the control. The Neutrase hydrolysate showed the highest 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity ($IC_{50}=3.6mg/mL$). Therefore, Neutrase was identified as the optimal enzyme for hydrolyzing egg-white protein to yield antioxidant peptides. During Neutrase hydrolysis, the reaction rate was rapid over the first 4 h, and then subsequently declined. The $IC_{50}$ value was lowest after the first hour (2.99 mg/mL). The emulsifying activity index (EAI) of EPH treated with Neutrase decreased, as the pH decreased. The EPH foaming capacity was maximal at pH 3.6, and decreased at an alkaline pH. Digestion resulted in significantly higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ABTS radical scavenging activity. The active peptides released from egg-white protein showed antioxidative activities on ABTS and DHHP radical. Thus, this approach may be useful for the preparation of potent antioxidant products.