• 생약학회지
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• 제31권2호
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• pp.185-189
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• 2000

This study was carried out to investigate the structure of antioxidative constituents and the free radical scavenging effect of the main ingredients from Galla Rhois(Rhus javanica Linne). Antioxidative activities of n-hexane, EtOAc and BuOH extracts of Galla Rhois were similar or even higher than that of natural (tocopherol) or synthetic antioxidant (BHA). It is suggested that major fractions for the antioxidative activity of Galla Rhois were the n-hexane, EtOAc and BuOH extract compartments. In the subsequently experiment, one active compound from n-hexane extract, three active compounds from EtOAc extract and one active compound from BuOH extract were isolated. Their chemical structures were identified as syringic acid, protocatechuic acid, gallic acid methylester, gallic acid and $1,2,3,4,6- penta-O-galloyl-{\beta}-D-glucose$ on the basis of the speculation of spectral data and chemical reaction. Among the compounds, protocatechuic acid, gallic acid methylester and $1,2,3,4,6- penta-O-galloyl-{\beta}-D-glucose$ showed most potent radical scavenging effect using DPPH method.

• Natural Product Sciences
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• 제11권1호
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• pp.1-9
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• 2005

The chemical constituents from Hedyotis diffusa Willd and their pharmacological activities were summarized. It has been known data that this herb contains anthraquinones, terpenoids, steroids, flavonoids, organic acid, and polysaccharides. The studies of pharmacology have shown that Hedyotis diffusa Willd possess various levels of activities such as anticancer, anti-inflammatory, immunostimulatory, antioxidative, neuroprotective, and hepatoprotective activities.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.3102-3102
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• 2001

Constituents of several .representative seaweeds, such as wakame Undaria pinnatifida; hijikia Hizikia fusifome; and kombu Laminaria japonica, were found to have fairly large reaction rates determined by quenching experiments of emission spectra in the near-infrared region (1max: 1270 nm) from singlet oxygen (102). Emission spectra of singlet oxygen generated from an aqueous solution of Rose Bengal under irradiation with a green laser (330 nm) were measured by a near-infrared (NIR) emission spectrometer constructed in our laboratory. The quenching experiments were as follows: Intensities of emission spectra were measured in the absence (I0) and in the presence of the seaweed constituents (I): Ratios of I0/I were plotted against every concentration of the quenchers (Stern-Volmer plots) which gives a straight line. The slope of each line gives a kqt value which gives a quenching constant kq value (an antioxidative constant against singlet oxygen) when the t value (half-life time of singlet oxygen in the solvent used) was given. The determined reaction rates are between 103-105 (g/l)-ls-1; the larger ones are as large as that of ascorbic acid, 8.4 ${\times}$ 104 (g/1)-ls-1. Most of these seaweed constituents also showed antioxidative activity against auto-oxidation and superoxide as well as their immunological enhancing activity. These results suggest a possibility that dietary fibers which are supposed to prevent the large-intestine cancer by their physical properties may prevent the cancer, at least in parts, by their chemical, antioxidative activity.

• Natural Product Sciences
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• 제9권4호
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• pp.245-248
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• 2003

A phytochemical investigation on the methanolic extract of Cosmos caudatus has led to the isolation of quercetin $3-O-{\beta}-D-arabinofuranoside$ (1), quercetin $3-O-{\beta}-D-rhamnoside$ (2), quercetin $3-O-{\alpha]-D-glucoside$ (3) and quercetin (4). These compounds were shown to be the antioxidative constituents of the plant when evaluated using the ferric thiocyanate (FTC) and thiobarbituric acid (TBA), and radical scavengers based on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assays.

• Natural Product Sciences
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• 제9권1호
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• pp.7-9
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• 2003

The antioxidative constituents isolated from Hedyotis diffusa were identified as quercetin 3-O-${\beta}$-rutinoside (1) and quercetin 3-O-${\beta}$-glucoside (2). We also isolated asperuloside (3) from this plant. Identification was done based on spectroscopic analysis. Quercetin 3-O-${\beta}$-rutinoside was the stronger antioxidant than quercetin 3-O-${\beta}$-glycoside while asperuloside was inactive.

• Archives of Pharmacal Research
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• 제27권2호
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• pp.173-176
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• 2004

Three phenolic compounds, rosmarinic acid (1), methyl rosmarinate (2), ethyl rosmarinate (3), and two flavonoids, luteolin (4), luteolin-7-O-$\beta$-D-glucuronide methyl ester (5) were isolated from the aerial part of Lycopus lucidus (Labiatae). Their structures were determined by chemical and spectral analysis. Compounds 1-5 exhibited potent antioxidative activity on the NBT superoxide scavenging assay. The $IC_{50}$ values for compounds 1-5 were 2.59, 1.42, 0.78, 2.83, and 3.05 $\mu\textrm{g}$/mL respectively. In addition, five compounds were isolated from this plant for the first time.

• 약학회지
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• 제47권4호
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• pp.212-217
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• 2003

We have carried out the antioxidative activity of nuts species for the development of antioxidant from natural products. From our previous report, EtOAc and n-BuOH extracts of acorn hull and chestnut hull were found to have a strong antioxidative activity in various antioxidant experiment. In the continuous study, we isolated several compounds from EtOAc and n-BuOH extracts of acorn hull and chestnut hull by fractionation using column chromatography. The structures of isolated compounds were identified as catechin, naringenin and ellagic acid on the basis of their spectroscopic properties and by comparison of their physical and spectra data with published value. Antioxidative activities of catechin, naringenin and ellagic acid were measured by DPPH, ferric-thiocyanate and Rancimat method.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2007년도 Proceedings of The Convention of The Korean Society of Applied Pharmacology
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• pp.115-121
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• 2007

Opuntia ficus-indica var. saboten (Cactaceae) is widely cultivated in Jeju Island (South Korea) for use in the manufacture of health foods such as tea, jam and juice. Its fruit and stem have been traditionally used as oriental folk medicine to treat diabetes, hypertension, asthma, burns, edema and indigestion. During the search for naturally occurring antioxidative neuroprotective agents, it was found that the ethyl acetate fraction of the stems and fruits of Opuntia ficus-indica var. saboten exhibited potent antioxidant effect. Using a chromatographic fractionation method, several constituents were isolated from this fraction. Among isolates, KYS50182 showed the most potent in vitro and in vivo neuroprotective activities, suggesting that the flavonoid can serve as a lead structure for the development of neuroprotective agents by providing neuroprotection against oxidative and focal ischemic neuronal injuries.

• Natural Product Sciences
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• 제15권4호
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• pp.241-245
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• 2009

In the course of screening for antioxidant compounds by measuring the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging effect and superoxide quenching activity, methanol extract of Cyperus difformis (Cyperaceae) was found to show potent antioxidant activities. Subsequent activity-guided fractionation of the methanolic extract led to the isolation of three phenolic compounds, rosmarinic acid (1), luteolin (2) and caffeic acid (3). Their structures were elucidated by spectroscopic studies. Three compounds showed the significant antioxidative effects on DPPH and nitric oxide radical scavenging effects, riboflavin and xanthin originated superoxide quenching activities. Among them, compound 3 showed the most significant antioxidative effects on those four antioxidant tests. Compound 3 showed better antioxidative activities than vitamin C.

• 대한화장품학회지
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• 제35권3호
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• pp.251-256
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• 2009

개가시나무 가지의 에탄올 추출물에서 항산화활성을 관찰하였으며, 활성성분을 규명하기 위한 연구를 진행하였다. 그 결과, 4종류의 화합물을 분리하여 동정하였다. 분리 동정된 성분은 catechin(1), epi-catechin(2), tyrosol(3) 및 tiliroside(4)이다. 분리 성분의 항산화활성은 DPPH 라디칼 및 superoxide 음이온 라디칼 소거활성을 이용하여 측정하였다. 화합물 1, 2, 3, 4는 $100{\mu}L$/mL 농도에서 각각 94.2 %, 93.4 %, 33.6 %, 11.2 %의 DPPH 라디칼 저해활성을 나타내었다. 또한, 화합물 1, 2, 3, 4는 $200{\mu}L$/mL 농도에서 각각 60.2 %, 35.1 %, 20.6%, 4.5 %의 superoxide 음이온 라디칼 저해활성을 나타내었다. 화합물 $1{\sim}4$는 개가시나무에서는 처음으로 분리된 물질이다.