• Proceedings of the KAIS Fall Conference
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• 2010.11b
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• pp.733-736
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• 2010

제주조릿대 잎 열수 추출 진액을 첨가한 식초음료를 개발하기 위해 항산화 활성을 관찰하였다. 항산화활성은 DPPH radical 소거활성, Hydroxyl radical 소거 활성 실험을 진행하였다. Base 식초를 선택하기 위한 쌀 식초와 사과식초의 DPPH 라디칼 소거활성에서는 식초 원액에 비해 제주조릿대를 첨가하였을 때 쌀 식초는 최대 68.07%증가하는 것을 확인 할 수 있었고, 사과식초의 경우 78.74% 증가하는 것을 확인할 수 있었다. 맛, 향, 단가, 항산화활성을 통하여 사과식초를 Base식초로 선택하였으며, Base식초와 제주조릿대 진액의 혼합비를 결정하기 위하여 배합율에 따른 항산화활성 연구에서는, DPPH 라디칼 소거활성의 경우 제주조릿대의 비율이 높아짐에 따라 DPPH 라디칼 소거능 역시 증가하는 것을 확인 할 수 있었다. Hydroxyl 라디칼 소거활성의 경우, 제주조릿대 진액의 비율을 증가시킬 수록 활성이 조금씩 떨어졌으나, 대조군인 석류와 블루베리 식초에 비해서는 10%이상 높은 소거활성이 있는 것을 확인할 수 있었다.

• Journal of Marine Bioscience and Biotechnology
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• v.1 no.3
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• pp.170-177
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• 2006

As a rapid and quick bioactive compound evaluation technique, in this study we utilized a automatic system of High Throughput Screening (HTS) to investigate DPPH radical scavenging efficacy of seaweeds, collected from Jeju Island in Korea. In this study, 6 species of green seaweeds, 18 species of brown seaweeds and 22 species of red seaweeds extracted with methanol at $20^{\circ}C$ and $70^{\circ}C$ were subjected to HTS. Of the green seaweeds tested, Enteromorpha compressa (20G6) of the green seaweeds showed DPPH radical scavenging activity of over 60%. On the other hand, the other green seaweeds showed poor DPPH radical scavenging activities (lees than 40%) at 1 mg/ml. Sargassum siliquastrum (20B17, 70B17), Dictyota dichotoma (70B1), Sargassum coreanum (70B16) and Ecklonia cava (70B26) among the brown seaweeds showed significantly high DPPH radical scavenging activity with 96%, 97%, 92%, 92%, 87%. Polysiphonia japonica (20R24), Schizymenia dubyi (20R17), Gelidium amansii (20R18) and Acrosorium flabellatum (20R23) among the red seaweeds showed remarkable DPPH radical scavenging activity of over 90%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.12
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• pp.1793-1798
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• 2015

Antioxidant activities of various solvent extracts from Coriolus versicolor were investigated for their total polyphenol content, total flavonoid content, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation radical scavenging activity. C. versicolor extracts were produced by organic solvents such as ethanol, ethyl acetate, and methanol. Total polyphenol and flavonoid contents in the ethanol and ethyl acetate extracts were higher than those in the methanol extract. DPPH radical scavenging activity of methanol extract showed the highest value of 80.3%, which was similar to that of ascorbic acid (85.5%). All extracts showed good (>90.0%) ABTS cation radical scavenging activity. The antimicrobial activities of these extracts from C. versicolor were evaluated against six strains of bacteria using the disc diffusion method. All extracts showed antimicrobial activities against all tested bacteria except Staphylococcus aureus. These results indicate that various extracts from C. versicolor could be useful as natural antioxidant and antimicrobial agents.

• Food Science and Preservation
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• v.24 no.6
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• pp.879-884
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• 2017

In a continuing screening of selected medicinal plants native to Mongolia, the antioxidant and ${\alpha}$-glucosidase inhibitory activities of methanol extract of Iris bungei were investigated. After extraction with 80% of methanol, the methanol fraction was further extracted with n-hexane, EtOAc and n-BuOH in order to obtain four different solvent-soluble fractions, namely n-hexane-soluble, EtOAc-soluble, n-BuOH-soluble and $H_2O$ residue. The antioxidant properties were evaluated by radical scavenging assay using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) ($ABTS^+$) radicals. The anti-diabetic efficacy of I. bungei extract was investigated by ${\alpha}$-glucosidase assay. All tested samples showed dose-dependent radical scavenging and ${\alpha}$-glucosidase inhibitory activities. Among the tested extracts, the EtOAc-soluble fractions showed the greatest radical scavenging activity and ${\alpha}$-glucosidase inhibitory properties among other solvent-soluble fractions. This result suggested that there was a significant relationship between the total phenolic content and biological efficacy. Thus, I. bungei extract might be considered as a new potential source of natural antioxidant and as a ${\alpha}$-glucosidase inhibitory source. A more systematic investigation of this biomass sill be performed for further investigation of activity against antioxidative and anti-diabetic effects.

• Korean Journal of Food Science and Technology
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• v.45 no.2
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• pp.206-212
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• 2013

In the current study, antioxidant properties of extracts from different parts of Taraxacum officinale were determined by measuring the radical scavenging activity of 1,1-diphenyl-2-picryl hydrazyl(DPPH) and 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). The antioxidant activity of aerial and root parts of this plant was measured in extracts obtained from various solvents, e.g., water, 50, 70, 100% ethanol, and hot-water. The hot-water extracts had the highest radical scavenging activities. A further study was conducted to determine the total antioxidant activity of hot-water extract fractions obtained from different solvents, e.g., chloroform, ethyl acetate, n-butanol, and water. The ethyl acetate fraction of this extract displayed the strongest DPPH and ABTS radical scavenging activity and the highest total phenolic contents. The inhibitory effect of individual solvent fractions on the production of nitric oxide in LPS-stimulated RAW 264.7 cells was measured. The results indicated that the ethyl acetate fraction of aerial and roots part extracts significantly reduced nitric oxide productions.

• Korean Journal of Medicinal Crop Science
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• v.11 no.1
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• pp.1-4
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• 2003

Two antioxidative compounds in Chrysanthemum boreale were isolated by a bioassay using a 2, 2-diphenyl-1-picrydrazyl(DPPH) free radical. They were identified as apigenin, linarin(acacetin-7-O-rutinoside) on the basis of $^1H\;and\;^{13}C-NMR$ and MS data. The DPPH radical scavenging activity$(RC_{50}:\;13.3{\mu}g)$ of apigenin was similar to that of ${\alpha}-tocopherol\;(12.1{\mu}g)$ and L-ascorbic acid$(13.1{\mu}g)$

• Food Science and Preservation
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• v.23 no.7
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• pp.989-994
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• 2016

As part of our continuing search for bioactive natural products, the antioxidant and ${\alpha}$-glucosidase inhibitory activities of an 80% methanolic extract and organic solvent soluble-portions of Aruncus dioicus var. kamtschaticus roots were investigated by using a bioassay system. The antioxidant activity of A. dioicus var. kamtschaticus roots extract and organic solvent soluble-portions were assessed by examining with 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) ($ABTS^+$) radical scavenging. In addition, anti-diabetic effects of the A. dioicus var. kamtschaticus root extract and organic solvent soluble-portions were tested via ${\alpha}$-glucosidase inhibition assay. The total phenolic contents of the products were determined by applying UV-VIS spectrophotometry. All tested samples showed dose-dependent radical scavenging and ${\alpha}$-glucosidase inhibitory properties. In particular, the ${\alpha}$-glucosidase inhibitory and radical scavenging effects of the ethyl-acetate (EtOAc)-soluble portion from the roots of A. dioicus var. kamtschaticus were greater than those from other solvent-soluble portions. These results indicate that A. dioicus var. kamtschaticus could be considered a new effective source of natural antioxidants and anti-diabetic materials. More systematic research of the constituents of the roots of this A. dioicus variety will be conducted to further develop its antioxidative and anti-diabetic properties.

• Korean Journal of Food Science and Technology
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• v.40 no.3
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• pp.283-289
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• 2008

This study used response surface methodology (RSM) in an effort to optimize the hot water extraction conditions of dandelion leaves in order to increase antioxidant activity in the extract. A central composite design was applied to investigate the effects of independent variables, which included the ratio of solvent to sample ($X_1$), extraction temperature ($X_2$), and extraction time ($X_3$), on dependent variables of the extracts, including soluble solid ($Y_1$), total polyphenols ($Y_2$), total flavonoid ($Y_3$), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability ($Y_4$), 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging ability ($Y_5$), and superoxide radical scavenging ability ($Y_6$). The estimated optimal conditions were as follows: $83.77{\pm}1.07^{\circ}C$ of the extraction temperature, $20.85{\pm}0.24 mL/g$ of solvent per sample, and $1.59{\pm}0.12$ hr of extraction time. At the optimal conditions, the predicted characteristic values were: a yield of 38.98%, a total polyphenol level of $74.28{\mu}g/mg$, a total flavonoid level of $74.00{\mu}g/mg$, a DPPH radical scavenging ability ($IC_{50}$) of 0.14 mg/mL, a ABTS radical scavenging ability ($IC_{50}$) of 3.24 mg/mL, and a superoxide radical scavenging ability ($IC_{50}$) of 2.49 mg/mL.

• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.442-447
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• 2009

Extracts from various parts of oriental melon were obtained and antioxidant property and antioxidant constituents including total phenol, total flavonoid, total vitamin C were examined. Free radical scavenging activity was measured by DPPH and ABTS method. Peel part of oriental melon showed the most potent scavenging activities against DPPH and ABTS radicals. The contents of total phenol, total flavonoid in peel were higher than other parts except vitamin C. The amount of vitamin C was the highest in placenta. The relationship between antioxidant activities and antioxidant constituents was determined and showed higher correlation coefficients between antioxidant activities and content of total phenol than other constituents. The above results suggest that phenolic compounds affect antioxidant activity of oriental melon and oriental melon has a good promise as functional food for enhancing health.

• Journal of Marine Bioscience and Biotechnology
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• v.1 no.4
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• pp.252-259
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• 2006

Extracts which were prepared by four different extractions - 80% methanol extracts (ME) at high ($70^{\circ}C$) and a room temperature ($20^{\circ}C$), respectively and aqueous extracts (AE) at both temperatures with the residue after the methanol extracts - of 10 green, 19 brown and 25 red seaweeds collected in Jeju Island coast were examined for their DPPH free radical scavenging activity using a ESR (electron spin resonance) spectroscopy. A variety of the extracts showed positive scavenging effect against DPPH free radical (except the green seaweeds). Among the extracts, the brown seaweed extracts exhibited the highest scavenging activity. Especially, Sargassum spp. of the brown seaweeds have remarkable scavenging activities - both methanolic and aqueous at the both temperatures ($20^{\circ}C$ and $70^{\circ}C$). On the other hand, ME showed better scavenging activity than AE in the red seaweed extracts. These results indicate that autogenous seaweeds in Jeju will be potential natural antioxidants for functional food compounds.