• Journal of the Korean Wood Science and Technology
• /
• 제31권6호
• /
• pp.67-72
• /
• 2003

The leaves of D. racemosum showed strong DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity and the order of the radical scavenging activity against DPPH radical is ethyl acetate (EtOAc) fraction>crude extracts>residue fraction>hexane fraction>ether fraction, under the experimental conditions. Since EtOAc fraction has highest antioxidative activity among these fractions, the isolation was performed from the EtOAc fraction of the leaves of D. racemosum and four phenolic compounds were isolated and identified as follows: methyl gallate, kaempferol, quercetin and quercitrin. The free radical scavenging activities of these compounds were 79.9%, 93.1%, 93.6% and 66.7% at 10 ㎍/ml, respectively. The IC₅₀ of compound 1, compound 2, compound 3 and compound 4 were 6.1, 4.1, 3.6 and 6.5 ㎍/ml, respectively. These compounds have higher antioxidative activity compared with reference compounds, ascorbic acid (IC₅₀ = 9.6 ㎍/ml).

• Journal of Microbiology and Biotechnology
• /
• 제19권12호
• /
• pp.1573-1575
• /
• 2009

Bioassay-guided fractionation of the culture broth of Aspergillus sp. FN070449 (KCTC 26428) using a DPPH (2,2-diphenyl-1-picrylhydrazyl) assay led to the isolation of two compounds: reticulone (1) and reticulol (2). Their chemical structures were elucidated on the basis of UV, IR, NMR, and MS spectroscopic analyses. Compound 1 exhibited more potent free radical scavenging activity on $ABTS^{\cdot+}$ (2,2'-azino-bis [3-ethylbenzthiazoline-6-sulphonic acid]) and DPPH radicals than did butylated hydroxyanisole (BHA) and caffeic acid.

• KSBB Journal
• /
• 제25권1호
• /
• pp.55-61
• /
• 2010

To investigate antioxidant activity of the culture broth from submerged culture of Tremella fuciformis, we preferentially analyzed the chemical composition of culture broth, which was mainly composed of carbohydrate (296.39 mg/g) and protein (9.24 mg/g), respectively. Also, contents of polyphenols, flavonoids and flavonols were 16.63 mg/g, 9.19 mg/g and 83.74 ${\mu}/g$, respectively. Next, we examined the scavenging abilities on DPPH (1,1-diphenyl-2-picrylhydrazyl) radical, ABTS (2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid) radical, the reducing power, and chelating ability on ferrous ions. All antioxidant activities of the culture broth were increased in proportion to its concentrations. The $IC_{50}$ values were in order as follows ABTS radical scavenging activity < OPPH radical scavenging activity < chelating power. Accordingly, these results suggest that pharmacological function of T. fuciformis might be due to, at least partially, their protective effects against oxidation and the culture broth of T. fuciformis was free radical inhibitors or scavengers at low concentration, involving possibly in termination of free radical reaction as primary antioxidants.

• 한국표면공학회지
• /
• 제53권5호
• /
• pp.265-270
• /
• 2020

We investigated mechanochemical radical, which is concomitant with chemical lift-off lithography(CLL), on the self-assembled monolayer(SAM)/electrodes and a polydimethylsiloxane(PDMS) using a colorimetric and a spectroscopic method. The 11-mercaptoundecanol(MUO)/Au or the 11-hydroxyundecylphosphonic acid (HUPA)/ITO were contacted with bare or activated PDMS. After contact, the each of SAM/substrates and the PDMS were immersed in a 2,2 Diphenyl-1-picrylhydrazyl(DPPH) radical scavenger. The color of the DPPH exposed to the PDMS was changed from purple to yellow and the absorbance decreased definitely at 515 nm wavelength. The SAM/substrates, however, have caused small changes in spectroscopic property, indicating no existence of radical species. We concluded that mechanochemical radicals were formed by homolytic cleavage of PDMS molecules upon external force and hardly transferred on the SAM/substrates.

• 농업과학연구
• /
• 제39권1호
• /
• pp.81-86
• /
• 2012

In this study, the antioxidative effect and protective potential against oxidative damage of extract and fractions from broccoli were investigated under in vitro and cellular system. The methanol (MeOH) extracts of broccoli flowers and sprouts were partitioned as dichloromethane, n-butanol (BuOH) and aqueous fractions. The comparison of antioxidative effect of broccoli flowers and sprouts showed that broccoli sprouts exerted the more effective protective activity from 2,2'-azobis (2-aminopropane) dihydrochloride (AAPH)-induced oxidative stress in LLC-$PK_1$ porcine renal epithelial cell. In addition, the extract and fractions from broccoli sprouts showed strong scavenging effect of 1,1-diphenyl-2-picrylhydrazyl radical and the BuOH fraction exerted the strongest activity. Therefore, the BuOH fraction was evaluated as the most active fraction with strong radical scavenging activity among the fractions of broccoli flowers and sprouts. The present study suggests the antioxidative potential against free radical-induced oxidative damage of flowers and sprouts of broccoli. In addition, the BuOH fraction of broccoli is considered as the active fraction with antioxidative effect.

• Food Science and Biotechnology
• /
• 제15권1호
• /
• pp.39-43
• /
• 2006

Levels of quercetin in different parts of onion were investigated using high performance liquid chromatography (HPLC) and liquid chromatography mass spectrometry (LC/MS) suitable for use with functional food material. Two main peaks were observed on HPLC chromatograms from the extracts of the skin, and the outer, middle, and core parts of onion. Using LC/MS, peak 1 was tentatively identified as quercetin monoglucoside at m/z 466.4, and peak 2 as quercetin with [M]+ at m/z 303.3. The levels of quercetin in the skin, and the outer, middle and core parts of the plant were 16.83,2.67,0.95, and 0.35 mg/g, respectively. In the study of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, skin, the nonedible part, contained the highest amount of quercetin, compared to the other edible parts, and showed the highest DPPH radical scavenging activity. Levels of quercetin and DPPH radical scavenging activity increased from core to skin. All parts of onion exhibited the strongest antibacterial activity only against Staphylococcus aureus and Vibro parahaemolyticus. Antibacterial activities of onion exhibited that S. aureus was more sensitive than V. parahaemolyticus. Among the four onion extracts, the middle part showed the strongest inhibitory activity against S. aureus but all onion extracts showed similar antibacterial activities against V. parahaemolyticus.

• Food Science and Biotechnology
• /
• 제18권2호
• /
• pp.312-316
• /
• 2009

Antioxidant-rich oils were extracted from different parts of sea buckthorn berry with supercritical $CO_2$ (SC-$CO_2$) and n-hexane. The functional components were analyzed and the extracts were screened for their potential as radical scavengers in 1,1-diphenyl-2-picrylhydrazyl radical (DPPH), 2,2'-azinobis-3-ethylbenzotiazoline-6-sulphonic acid (ABTS), galvinoxyl systems. Minor differences were found in fatty acid composition of oils extracted by the two methods. Seed oil contains the highest content of tocopherols while pulp oil and whole berry oil possessed higher concentration of carotenoids. Whole berry oil, pulp oil, and seed oil extracted by SC-$CO_2$ showed 91.7, 90.9, and 93.5% radical scavenging activity (RSA) at 6 mg/mL towards DPPH and 74.3, 54.3, and 74.8% towards galvanoxyl radical at 10 mg/mL. The hexane-extracted oils showed similar scavenging ability. However, the oils obtained by hexane showed significantly higher RSA (p<0.05) than those obtained by SC-$CO_2$ while whole berry oil has the highest RSA towards ABTS among 3 oil samples.

• 공업화학
• /
• 제26권4호
• /
• pp.470-476
• /
• 2015

본 연구에서는 떡쑥 추출물로부터 3가지 dicaffeoylquinic acid (DCQA)를 분리 정제하여 구조를 결정하고, 항산화 활성, 세포보호효과, 그리고 tyrosinase 저해 활성을 평가하였다. 떡쑥 추출물의 에틸아세테이트 분획에 대하여 크로마토그래피, $^1H$-NMR 및 MS 분석을 한 결과, 분리된 화합물은 총 3가지 DCQA 유도체 : 3,5-dicaffoylquinic acid (3,5-DCQA, 1), 4,5-dicaffeoylquinic acid (4,5-DCQA, 2), 1,5-dicaffoylquinic acid (1,5-DCQA, 3)로 나타났다. 분리된 compound 1-3의 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical 소거활성($FSC_{50}$)은 각각 3.70, 5.80 및 $5.50{\mu}M$로 지용성 항산화제로 알려진 (+)-${\alpha}$-tocopherol ($FSC_{50}=21.90{\mu}M$)과 비교하여 더 큰 free radical 소거활성을 나타내었다. compound 1-3의 $^1O_2$로 유도된 사람 적혈구의 광용혈에 대한 세포보호효과는 (+)-${\alpha}$-tocopherol과 유사한 세포보호활성을 나타내었다. Compound 1-3의 tyrosinase 저해활성($IC_{50}$)은 각각 0.15, 0.16, 및 0.13 mM로 미백성분으로 알려진 arbutin ($IC_{50}=0.33mM$)과 비교하여 높은 tyrosinase 억제효과를 나타내었다. 이상의 결과들은 세 가지 DCQA가 식품 또는 화장품 산업에서 항산화 및 미백 기능성 소재로서 응용가능성이 있음을 시사한다.

• Preventive Nutrition and Food Science
• /
• 제15권1호
• /
• pp.30-35
• /
• 2010

The potential biological activities of methanol extract and 5 fractions (hexane, $CH_2Cl_2$, EtOAc, BuOH and water) from roots of Astragalus membranaceus were examined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, hydroxyl radical (${\cdot}OH$) scavenging activity, reducing power assays, lipid peroxidation inhibitory activity, $\alpha$-amylase and $\alpha$-glucosidase inhibition assays. The EtOAc fraction showed high DPPH free radical scavenging activity ($EC_{50}=170.34\;{\mu}g/mL$), hydroxyl radical scavenging activity ($EC_{50}=32.14\;{\mu}g/mL$), lipid peroxidation inhibitory activity ($EC_{50}=52.46\;{\mu}g/mL$) and a concentration dependence, with OD value ranging from 0.234 to 0.345 (0.1 to 0.5 mg/mL), for reducing power. The EtOAc fraction has the highest total phenolic content ($142.13\;Gal\;{\mu}g/mg$) and the $CH_2Cl_2$ fraction has the highest flavonoid content ($71.63\;Que\;{\mu}g/mg$). Meanwhile, hexane and EtOAc showed certain $\alpha$-amylase and $\alpha$-glucosidase inhibition activities. These results suggest that the methanol extract and fractions from Astragalus membranaceus root have significant antioxidant and anti-diabetes activities, which could be used as a potential source of pharmaceutical materials.

• Food Science and Biotechnology
• /
• 제18권4호
• /
• pp.1042-1045
• /
• 2009

A commercial propolis was investigated in terms of its antioxidant, antimicrobial, and antiproliferative activities. The contents of total phenol and flavonoid of propolis were 8.3 and 6.6 mg, respectively. The reducing power of the propolis increased with concentration increasing. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was shown at 82.70% in 1,000 ${\mu}g/mL$ of the propolis. 2,2'-Azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging effect of antioxidant activity on the propolis was 35.64 g/sample. The propolis showed high antimicrobial activity against Bacillus cereus at all concentration of propolis. All of the cancer cell lines have 53-73% as effective growth inhibition. These results showed that the commercial propolis has potential antioxidant, antimicrobial, and cancer cell proliferative inhibition activities thus, propolis can be applied to the functional food, pharmaceutical, and cosmetic industry.