• 한국자원식물학회지
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• 제10권3호
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• pp.227-230
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• 1997

The authors isolated four olefinic catechols, commonly referred to as urushiol, from the sap of Korean lacquer tree(Rhus vernicifera STOKES) with stronger antioxidative activities than $\alpha-tocopherol$. The hexane extract with a free radical scavenging activity was purified by silica and ODS gel column chromatography. The active compounds were identified by MS and $^1H-NMR$ as 3-[8'(Z),11'(Z),14'-pentadecatrienyl]catechol, 3-[8'(Z),11'(Z)-pentadecadienyl]catechol, 3-[8'(Z)-pentadecenyl] catechol, and 3-pentadecylcatechol. All of these compounds showed strong free radical scavenging activities on 1,1-diphenyl-2-picrylhydrazyl(DPPH) radical, in which 3-pentadecylacatechol exhibited the highest activity ($IC_{50}$: $1.2{\mu}g/ml$). They also showed a significant inhibitory activity on lipid peroxidation ($IC_{50}$: 2.1 - 3.5 ${\mu}g/ml$). The antioxidative activity of 3-pentadecylcatechol on DPPH radical and lipid peroxidation is approximately two times greater than that of $\alpha$-tocopherol. The results suggest that the urushiol derivatices may contribute to the preservative characteristics effective against oxidative stress and could be a good source for industrial applications including a coating material.

• Journal of Applied Biological Chemistry
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• 제62권2호
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• pp.143-147
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• 2019

This study evaluated the anti-oxidant activity of avicularin and isovitexin from Lespedeza cuneata using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl (OH) scavenging assays. The results showed that among the four fractions, the highest OH radical scavenging activity was exhibited by the n-butanol fraction. The DPPH radical scavenging activities of avicularin and isovitexin were higher than 50% at a concentration of $100{\mu}g/mL$. Moreover, one hundred micrograms per liter of avicularin and isovitexin exhibited effective anti-oxidant activity, with the OH radical scavenging rates being 87.54 and 91.48%, respectively. These results suggest that Lespedeza cuneata would be useful anti-oxidant agents from natural sources.

• Journal of Applied Biological Chemistry
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• 제50권3호
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• pp.115-119
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• 2007

To discover the sources with antioxidant and tyrosinase inhibitory activities in Korean traditional medicines, 10 extract of medicinal plants were screened for their potential to scavenge stable 1,1-diphenyl-2-picryhydrazyl (DPPH) free radical, inhibit hydroxyl radical (${\cdot}OH$), total phenolic content, and inhibition of tyrosinase. The potency of DPPH radical scavenging activity was shown in the extract of Ulmus davidiana var. japonica Nakai that has a greater effect with $IC_{50}$ values of $6.49{\pm}5.43{\mu}g/mL$, than BHA ($IC_{50}=20.99{\pm}0.74{\mu}g/mL$), L-ascorbic acid $(IC_{50}=20.59{\pm}1.06{\mu}g/mL),\;and\;{\alpha}-tocopherol\;(IC_{50}=25.55{\pm}0.26{\mu}g/mL)$ as a positive control. The ${\cdot}OH$ scavenging activities were observed in the plants tested. Acanthopanax senticosus, Cirsium setiders, U. davidiana exhibited scavenging activity of more than 60% at $500{\mu}g/mL$. The scavenging activity(%) of BHA and a-tocopherol were 64.32 and 55.87% at $500{\mu}g/mL$, respectively. The total phenolic content was determined, in order to assess its effect on the extract's antioxidant activity. The total phenoic content of $33.37{\pm}0.52mg/g$ was conformed by methanolic extract of U. davidiana. The U. davidiana and Morus bombycis exhibited tyrosinase inhibitory activity with a $34.28{\pm}1.32\;and\;75.57{\pm}1.10%$, respectively. In particular, M. bombycis has stronger tyrosinase inhibitory activity than albutin with $36.48{\pm}3.56%$ as a positive control. This work showed that the inhibitory abilities of Korean medicinal plants, such as U. davidiana and M. bombycis, on DPPH free radical, inhibit hydroxyl radical (${\cdot}OH$), and inhibition of tyrosinase and total phenolic content, can be useful in the prevention and treatment of free radical-relate disease. Investigations into further isolation of inhibitory principles of U. davidiana and M. bombycis are now in progress.

• 농업과학연구
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• 제45권4호
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• pp.761-767
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• 2018

Degenerative diseases are commonly associated with excess free radicals. Acer okamotoanum, a plant endemic to Korea, is reported to have anti-oxidant, anti-cancer, and anti-viral activities. We previously isolated flavonoids from the ethyl acetate fraction of A. okamotoanum such as quercitrin (QU), isoquercitrin (IQ), and afzelin (AF). In the present study, the in vitro antioxidant activity of flavonoids such as QU, IQ, and AF isolated from the ethyl acetate fraction of A. okamotoanum were investigated by measuring the free radical scavenging activity including 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical ($^{\cdot}OH$), and superoxide anion ($O_2{^-}$). The flavonoids (QU, IQ, and AF) concentration-dependently showed a DPPH radical scavenging activity. In particular, QU and IQ showed a higher DPPH radical scavenging activity than that of AF. In addition, the flavonoids (QU, IQ, and AF) at $10{\mu}g/mL$ showed over an 80% scavenging effect against $^{\cdot}OH$ radical production. Furthermore, the $O_2{^-}$ radical scavenging activity of the flavonoids, QU, IQ, and AF increased in a dose-dependent manner. Particularly, IQ exerted the strongest scavenging activities against $^{\cdot}OH$ and $O_2{^-}$ radicals among the other flavonoids. These results indicate that the flavonoids from A. okamotoanum, in particular IQ, would have a protective activity against oxidative stress induced by free radicals, and potentially be considered as a natural antioxidant agent.

• Natural Product Sciences
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• 제17권4호
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• pp.267-272
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• 2011

In our search for bioactive phenolics from plants, the culms of Phyllostachys bambusoides has been selected for investigation of anti-cariogenic and 1,1-diphenylpicrylhydrazyl (DPPH) radical scavenging agents based on the initial screening results. Fractionation process of n-hexane and $CHCl_3$ extracts afforded four phenolic constituents, ferulic acid (1), vanillin (2), coniferaldehyde (3), and coniferyl alcohol (4) as guided by their DPPH free radical scavenging activities. Additionally, activity-guided fractionation of EtOAc extract with anti-cariogenic activity has resulted in the isolation of coniferaldehyde (3), 2,6-dimethoxy-p-benzoquinone (5), p-methoxycinnamic acid (6), (${\pm}$)-balanophonin (7), and 6-methoxychromanone (8). The structures of 1 - 8 were determined by spectroscopic data interpretation, and also by comparison of their data with the published values. Phenolic compounds 1 - 4 exhibited similar DPPH radical scavenging activities compared with the synthetic antioxidant, butylated hydroxytoluene (BHT), and compounds 3 and 5 - 8 showed significant antibacterial activity against cariogenic oral streptococci, Streptococcus mutans and S. sobrinus.

• 대한한방소아과학회지
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• 제24권2호
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• pp.126-136
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• 2010

Objectives The purpose of this study was to investigate the antiallergic and antioxidative effects of Chaenomeles Sinensis (CS). Methods CS pretreatments inhibited anti-DNP IgE in RBL-2H3 mast cells for an hour. we measured cell viability, $\beta$-hexosaminidase release, IL-4, TNF-$\alpha$ secretion, and IL-4, TNF-$\alpha$ mRNA expression CS pretreatments inhibited DNP-HSA($10\;{\mu}g/ml$) for ten minutes, we measured Dicholrodihydrofluorescein(DCF) and DPPH radical-scavenging activity in 0.5 mM 1,1-diphenyl-2-picrydrazyl(DPPH) radical solution, 0.1ml, 99% ethanol 0.8ml, and CS 0.1 ml mixed solution. Results 0, 1, 2, 3, 4, 5 mg/ml CS treatments were not affect on cell viability and inhibited b-hexosaminidase release, IL-4, TNF-$\alpha$ secretion, CS treatments also decreased IL-4, TNF-$\alpha$ mRNA expression in RBL-2H3 cells. CS treatments inhibited reactive oxygen species(ROS) and DPPH radical-scavenging activity. Conclusions These results suggest that CS may be useful for the prevention or treatment of allergic disease.

• 한국식품저장유통학회지
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• 제18권6호
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• pp.967-972
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• 2011

Assai 열매추출물의 자유 라디칼 소거능을 측정하기 위하여 DPPH를 이용한 자유 라디칼 소거능 실험을 수행하여 항산화 효과를 측정한 결과, assai열매추출물의 농도가 높을수록 DPPH활성이 뛰어남을 알 수 있었고, ROS를 이용하여 항산화 효과를 확인하였다. 배양된 대식세포에 assai열매추출물을 농도별로 첨가한 결과, 농도가 높을수록 과산화수소에 의해 유도된 산화적 자극이 감소하였다. 또한 세포 생존에 미치는 영향을 알고자 assai열매추출물을 농도별로 첨가하여 24시간후 세포의 형태변화를 MTT assay로 실시한 결과, 산화적 자극에 의해 발생한 세포 손상이 assai 열매추출물의 농도가 높아질수록 감소하는 것이 확인되었다. 따라서 assai열매추출물은 천연 항산화제로서의 가능성을 보였다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 춘계학술대회
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• pp.829-832
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• 2014

본 연구는 발효 홍국마로부터 에탄올 추출물 농도에 따른 생리활성 효과를 조사하기 위하여 실시하였다. 발효 홍국마 에탄올 추출물로부터 색소, DPPH radical 소거활성, 환원력 및 monacolin K 함량을 조사하였다. 그 결과, 기질로서 장마를 Monascus sp. MK805 균주로 발효하였을 때 홍국색소는 29.6(황색), 15.1(오렌지색), 20.4(적색), DPPH radical 소거활성은 72.8%, 환원력은 1.74 및 monacolin K 함량은 480.6 mg/kg으로 각각 조사되었다. 이처럼 발효 홍국마는 항산화 및 항고지혈증 관련 기능성 식품 및 의약품 소재로의 이용 기능성이 높은 것으로 사료된다.

• 한국식품영양학회지
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• 제28권2호
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• pp.295-301
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• 2015

삼채뿌리와 잎이 가진 기능성 식품소재로서의 활용도를 높이고자 다양한 생리활성을 평가하였다. 삼채뿌리의 조사포닌, 폴리페놀, 플라보노이드 함량은 각각 4.28 mg/g, 18.27 mg/g, 0.95 mg/g, 삼채잎의 조사포닌, 폴리페놀, 플라보노이드 함량은 각각 4.17mg/g, 35.91 mg/g, 2.79 mg/g으로 나타났다. 삼채뿌리 및 잎 부위의 70% 에탄올 추출물의 DPPH 라디칼 소거능 $IC_{50}$으로 23.01 mg/mL, 4.82 mg/mL로 나타났으며, hydroxyl radical 소거능 $IC_{50}$ 값이 각각 40.82 mg/mL, 27.24 mg/mL를 나타났다. ${\alpha}$-Amylase 저해 활성은 삼채뿌리 및 잎 부위 에탄올 추출물 10 mg/mL를 처리했을 때 억제활성이 각각 61.38%, 61.01%로 나타났다. 삼채뿌리 및 잎 부위의 아질산염 소거능을 측정한 결과, 삼채추출물의 농도가 증가함에 따라 그 활성 역시 증가하는 경향으로 나타났다. 이상의 결과로 삼채뿌리보다는 삼채잎 부위에 항산화 및 항당뇨 활성이 나타났으며, 삼채잎을 활용한 식품 소재로써 개발할 가치가 매우 높은 것으로 판단된다.

• 한국식품영양학회지
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• 제33권2호
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• pp.210-214
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• 2020

In this study, polyphenol and flavonoid contents were measured, and DPPH, OH, H₂O₂ radical scavenging activity, and the α-amylase inhibitory activity were measured to study the antioxidant activity of 70% ethanol extract from Morinda citrifolia L. The polyphenol and flavonoid contents of noni 70% ethanol extract were 29.52 GAE/g and 12.48 CE/g, respectively. Also, the IC₅₀ values of DPPH, hydroxyl radical, and hydrogen peroxide scavenging activity of 70% ethanol extract from noni were 18.70 mg/mL, 26.45 mg/mL, and 35.67 mg/mL, respectively. Measurement of the α-amylase inhibitory activity of 70% ethanol extract from noni showed 45% inhibitory activity at 10 mg/mL.