• Microbiology and Biotechnology Letters
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• v.41 no.3
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• pp.367-371
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• 2013

The half maximal inhibitory concentration ($IC_{50}$) values and trolox equivalent antioxidant capacity (TEAC) values were calculated by a 2,2'-diphenylpicrylhydrazyl (DPPH) assay and a 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid ($ABTS^{+{\cdot}}$) assay, in order to determine the antioxidative activities of the compounds. On the basis of the DPPH assay, quercetin had the strongest antioxidative potential of the flavonoids, followed in order by fisetin, 7,8-dihydroxyflavone, morin and kaempferol. Quercetin, fisetin and 7,8-dihydroxyflavone had higher antioxidant potentials than butyl hydroxyl anisole. Quercetin had the highest TEAC value amongst the flavonoids and isoflavonoids, followed in order by 3-hydroxyflavone, fisetin, 7,8-dihydroxyflavone and morin. Comparatively, isoflavonoids were found to have significantly weaker antioxidative potential than the flavonoids.

• Korean Journal of Food Science and Technology
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• v.42 no.4
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• pp.414-419
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• 2010

Hyphenated-HPLC techniques combine the separation power of HPLC with the structural and bioactivity information provided by NMR, ESI/MS, and an on-line antioxidant screening system. The major advantages over the traditional off-line techniques are rapidity and efficiency. In this study, we used hyphenated HPLC techniques including online HPLC-ABTS, LC-NMR, and LC-MS todirectly identify the major antioxidants of safflower (Carthamus tinctorius L.) seeds. The results demonstrated that the major antioxidant compounds from on-line HPLC-ABTS analysis were identified as 8'-hydroxyarcgenin-4'-O-$\beta$-D-glucoside, N-(p-coumaroyl) serotonin, and N-feruloylserotonin. Among them, N-feruloylserotonin accounted for almost 50% of the ABTS radical scavenging activity of the total extract. The results demonstrate that HPLC hyphenated techniques can be used to rapidly screen and structurally identify antioxidants from crude plant extracts.

• Food Science and Preservation
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• v.19 no.5
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• pp.751-756
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• 2012

Antioxidant capacity and acetylcholinesterase (AChE) inhibitory activity of the aqueous methanolic extract of Rhus javanica were investigated in vitro. The antioxidant properties was measured by radical scavenging assays using DPPH and $ABTS^+$ radicals. The AChE inhibitory efficacy of R. javanica was tested by Ellman's assay and the total phenolic content was determined using a spectrophotometric method. All tested samples showed a dose-dependent AChE inhibitory and radical scavenging activities. In particularly, ethyl acetate (EtOAc)-soluble portion from the methanolic extract of R. javanica showed significantly higher inhibitory activity than other organic solvent soluble-portions in an AChE and radical scavenging assay systems. These results suggest that R. javanica may be possess potential benefits which might be useful in development of antioxidant and anti-alzheimer's disease ingredient.

• Korean Journal of Plant Resources
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• v.24 no.2
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• pp.174-180
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• 2011

This study was conducted to investigate the optimum condition of extraction from fronds of Osmunda japonica to increase antioxidant compounds and antioxidant activity. Powder (1 g) of lyophilized fronds were mixed with three different solvents (MeOH, 80% EtOH and water). Extraction was carried out using not only by immersion (room temp.), heating ($60^{\circ}C$) and stirring (200 rpm) for 6 h, but also by sonication in 42 kHz ultrasonic bath for 15, 30 and 45 min. Extracts were filtered, and adjusted up to 50 mL to determine contents of soluble solids, total polyphenols and total flavonoids. Antioxidant capacity was measured by radical scavenging activity of 0.15 mM DPPH (2,2-diphenyl-1-picrylhydrazyl) and 7.4 mM ABTS [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)] radical. Among the solvents, MeOH and 80% EtOH appeared to be effective for extraction. Extract obtained from sonication in MeOH for 15 min resulted high polyphenol contents (45.15 $mg{\cdot}g^{-1}$ db) and DPPH radical scavenging activity ($RC_{50}$= 0.35 $mg{\cdot}mL^{-1}$). The highest flavonoid contents was obtained from immersion or heating extraction with MeOH (38.10~38.10 $mg{\cdot}g^{-1}$ db). ABTS radical scavenging was high in same extraction with 80% EtOH ($RC_{50}$= 0.21~0.22 $mg{\cdot}mL^{-1}$). Altogether, our results indicate that the extraction using ultrasonic bath with MeOH as a solvent (for 15~30 minutes) was the most effective way not only for increasing various antioxidant activities but also for saving labor and time in case of fronds of Osmunda japonica.

• Journal of Life Science
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• v.21 no.4
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• pp.576-583
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• 2011

In the course of study for the development of functional food ingredients from seaweeds having useful biological activities, the in-vitro antioxidant and nitrite scavenging activities of the methanol extracts prepared from 35 different seaweeds (17 phaeophyta, 11 rhodophyta and 7 chlorophyta) were determined. At $500\;{\mu}g/ml$ concentration of the methanol extracts, Ecklonia cava, Ecklonia stolonifera, Eisenia bicyclis (Kjellman) Setchell, Ishige foliacea, I. okamurai, Sargassum confusum, S. fulvellum, S. yamade and Zostera marina showed 60% more DPPH and ABTS scavenging activity. The exceptions were found in I. okamurai and Z. marina, which showed 45% and 53% ABTS scavenging activity, respectively. The correlation coefficient between DPPH and ABTS scavenging activities was 0.855, suggesting that the 9 different seaweeds extracts could scavenge anion and cation radicals concurrently. In reducing power, only E.cava, E.stolonifera and E.bicyclis showed above 0.88 ($Abs_{700}$). In a while, in nitrite scavenging activity at $100\;{\mu}g/ml$ concentration of the methanol extracts, 19 different seaweeds extracts including I. foliacea, I. okamurai, S. confusum, S. fulvellum, and S. yamade showed 60% more activity. Calculation of $IC_{50}s$ of DPPH, ABTS and nitrite scavenging activities of 9 different seaweeds extracts further showed that I. foliacea and S. yamade, besides E.cava, E.stolonifera and E.bicyclis, have strong antioxidant and nitrite scavenging activity. These results suggest that the selected 9 different seaweeds could be developed as functional food ingredients and I. foliacea and S. yamade have potential as novel natural sources of antioxidant and nitrite scavenger.

• Journal of Convergence for Information Technology
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• v.10 no.11
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• pp.168-176
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• 2020

Reactive oxygen species (ROS) damage DNA and cause cancer. Therefore, the research is being conducted on the development of antioxidants for the removal of ROS. This study was performed to investigate antioxidant activity and protective effect against oxidative DNA damage using ethyl acetate fractions from the cone of Pinus rigida × taeda (ERT). The antioxidant activity was evaluated using the DPPH, ABTS radical scavenging assay, reducing power assay, and Fe2+ chelating assay. Also, the contents of phenolic compounds and vitamin C related to antioxidant activity were analyzed to confirm phytochemicals. The DNA protective effect against oxidative stress was confirmed by the φX-174 RF I plasmid DNA cleavage assay. As a result, ERT showed DPPH and ABTS radical scavenging activities in a concentration-dependent manner. The results of reducing power and Fe2+ chelating activities were 77.32 ± 2.28% and 64.09 ± 1.01% at 200 ㎍/㎖. Also, ERT showed a DNA protective effect against oxidative stress.

• Food Science and Preservation
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• v.22 no.5
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• pp.708-713
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• 2015

To provide the basic data to dry vegetate the sweetpotato leaves, the total contents of tannin, flavonoid and polyphenol in the methanol extract from the hot-air dried sweetpotato leaves were analyzed and DPPH radical scavenging activity, ABTS radical scavenging ability, nitrite scavenging ability, and others were comparatively analyzed. The total tannin content was decreased from Shinmi of 10.87 mg/g at $40^{\circ}C$ to 7.28 mg/g at $70^{\circ}C$ and the total flavonoid was decreased from Hayanmi of 55.37 mg/g at $40^{\circ}C$ to 39.63 mg/g at $70^{\circ}C$. That is, the low temperature drying contained more of these substances than in the high temperature drying. The DPPH radical scavenging activity was the highest in Shinmi and Hayanmi of 84.33% and 85.25% at $40^{\circ}C$, and the ABTS radical scavenging ability was a high value of over 80% in the treatment plot at $40^{\circ}C$. The nitrite scavenging ability was highest in Shinmi and Hayanmi of 76.15% and 73.74% at $40^{\circ}C$ but low at $70^{\circ}C$. That is, the antioxidant effect of the hot-air dried sweetpotato leaves was high in the sample of $40^{\circ}C$ and low in the sample of $70^{\circ}C$. Affected by the drying temperature, the high antioxidant effect is resulting from the little decrease of active ingredient when drying at low temperatures.

• Journal of Life Science
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• v.21 no.1
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• pp.56-61
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• 2011

This study was performed to investigate effective extract conditions in fronds of the Ostrich fern (Matteuccia struthiopteris) to increase antioxidant compound contents and antioxidant capacity. Powder (1 g) of lyophilizated fronds were mixed with 3 kinds of solvents (MeOH, 80% EtOH and water). Extractions were carried out using not only immersion (room temp.), heating ($60^{\circ}C$) and stirring (200rpm) for 6 hr, but also through sonication in a 42 kHz ultrasonic bath for 15, 30 and 45 min. Extracts were filtrated and measured for contents of soluble solids (SS), total polyphenols (TP; tannic acid as a standard) and total flavonoids (TF; Naringin as a standard). Antioxidant activity was expressed as $RC_{50}$ for DPPH and ABTS radical scavenging. SS (0.317 $g{\cdot}g^{-1}$ db), TP (70.90 $mg{\cdot}g^{-1}$ db) and TF (41.53 $mg{\cdot}g^{-1}$ db) contents reached their highest levels when 30 minute sonication extraction with 80% EtOH was performed, and the highest DPPH and ABTS scavenging activity was observed in the same extraction conditions ($RC_{50}$=0.14 $mg{\cdot}ml^{-1}$ and 0.09 $mg{\cdot}ml^{-1}$, respectively). From the present investigation, it can be concluded that fronds of the ostrich fern can be used as a natural material for antioxidants, and sonication for 15-30 min with 80% EtOH is an ideal extraction method for increasing their antioxidant effects and saving extraction time.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.11
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• pp.1617-1622
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• 2016

This study was carried out to investigate antioxidant compounds (total polyphenol and total flavonoid) and antioxidant activities (DPPH radical scavenging activity, ABTS radical scavenging activity, FRAP activity, and reducing power] of the mycelium and fruit body of Sparassis crispa depending on extraction temperature ($60^{\circ}C$ and $95^{\circ}C$). For total polyphenols, total flavonoids, FRAP activity, and reducing power, the mycelium of S. crispa extracted at $95^{\circ}C$ showed the highest contents and activities. The mycelium of S. crispa extracted at $60^{\circ}C$ and fruit body of S. crispa extracted at $95^{\circ}C$ showed the highest DPPH radical scavenging activity and ABTS radical scavenging activity, respectively. This study suggests that the antioxidant activities of S. crispa extracted at $95^{\circ}C$ are better than those of S. crispa extracted at $60^{\circ}C$, and the mycelium contained more antioxidant compounds than the fruit body.

• Korean Journal of Food Science and Technology
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• v.46 no.4
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• pp.410-417
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• 2014

Berries and green tea are underutilized in the food industry despite their great potential as a functional food ingredients. The purpose of this study was to determine the extraction conditions under which total phenolic contents and antioxidant activities of berry and green tea extracts are maximized. Extracts produced using 0-80% ethanol and temperatures ranging from $5-65^{\circ}C$ were evaluated for total phenolic content (TP), as well as for DPPH and ABTS radical-scavenging activities by using response surface methodology. Both ethanol and temperature had significant effects (p<0.05). Ogaja extract produced at $67^{\circ}C$ by using 33% ethanol yielded maximum TP, ABTS, and DPPH values of 23.74 mg GAE/g, 19.77, and 25.04 mg VCE/g, respectively. Optimum conditions for mulberry and raspberry extraction were found to be $65^{\circ}C$ by using 69% and 40% ethanol, respectively. Mulberry and raspberry extracts had TP, DPPH, and ABTS values of 20.74 mg GAE/g, 23.55, and 35.44 mg VCE/g, and 26.08 mg GAE/g, 39.93, and 55.60 mg VCE/g, respectively. Green tea extraction at $57^{\circ}C$ by using 43% ethanol was found to be optimal, yielding TP, ABTS, and DPPH values of 101.15 mg GAE/g, 171.38, and 177.56 mg VCE/g, respectively.