• Korean Journal of Plant Resources
• /
• v.26 no.3
• /
• pp.347-354
• /
• 2013

Apple and pear are popular fruits consumed in Korea and are common fruit in daily diet. In order to compare the antioxidant activity of the apple and pear peels, total polyphenol contents, total flavonoid contents, $ABTS^+$ free radical scavenging activity, and DPPH free radical scavenging activity were measured from hot water, ethanol, and methanol extracts of the two fruit peels. The total polyphenol and flavonoid contents were highest in 95% methanol extracts of the apple peelsand 70% ethanol extract of the pear peels, respectively. Total polyphenol contents of the pear peels were higher than that of apple peels, and total flavonoid contents of the apple peels were higher than that of pear peels. The apple and pear peels had the highest $ABTS^{+{\cdot}}$ and DPPH free radical scavenging activity in 95% methanol extracts and 70% ethanol extracts, respectively. $ABTS^{+{\cdot}}$ and DPPH free radical scavenging activity of pear peels was higher than that of apple peels, and the DPPH free radical scavenging activity of apple and pear peels were detected in hot water, 95% methanol, and 70% ethanol extracts, respectively. Ascorbic acid, a synthetic antioxidant used as positive control, had significantly higher scavenging activity than the apple and pear peels. In conclusion, the apple and pear peelshave great potential as natural antioxidants. Therefore, above results should be considered to provide the possibility for the development of high functional antioxidants.

• Journal of Korean Society of Forest Science
• /
• v.102 no.4
• /
• pp.566-570
• /
• 2013

Vaccinium oldhamii Miq. is a Korean native tree, which is deciduous and shrub tree with broad leaf. To develop superior cultivars for edible or medicinal purposes, we evaluated total phenolic content and antioxidant activity. Total phenolic content was measured by folin-denis method and antioxidant activity was measured by DPPH free radical scavenging activity (DPPH method) and reducing power (potassium ferricyanide method). Total phenolic content, DPPH free radical scavenging activity (at 400 ppm) and reducing power (at 700 ppm) were 15.8~19.9 mg/g, 69.1~91.4% and 0.56~0.96, respectively. A linear correlation was shown between DPPH-radical scavenging activity and reducing power (r=0969).

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.33 no.7
• /
• pp.1112-1118
• /
• 2004

This study was carried out to evaluate the free radical scavenging effect and antioxidant effect of Cham-Dang-Gui (Angelica gigas) on cyclophosphamide (CYP) injected rats. Rats were divided into five groups： CON (normal group), ANS (CYP-injected and normal diet group), AND (CYP-injected and normal diet and Cham-Dang-Gui-treated group), ALS (CYP-injected and low iron diet group), and ALD (CYP-injected and low iron diet and Cham-Dang-Gui-treated group). CYP (30 mg/kg) was intraperitoneally injected to rats for early 3 days. Saline or Cham-Dang-Gui was administrated orally for entire experimental period. DPPH radical scavenger activity was measured by DPPH method, it was shown higher in methanol extract (81.5％) than in water extract (66.3％) of Cham-Dang-Gui. We observed the preventive effects of Cham-Dang-Gui on lipid oxidation of liver and protein oxidation of plasma. Hepatic SOD and catalase activities were significantly higher in CYP-injected group (ANS) than CON group, but SOD activity was slightly lowered in Cham-Dang-Gui treated group than CYP-injected group (ANS). These results suggest that extract of Cham-Dang-Gui could be useful for functional materials to reduce the oxidation of lipids and protein induced by free radicals.

• Advances in Traditional Medicine
• /
• v.8 no.1
• /
• pp.32-38
• /
• 2008

Galgeuntang water extract exhibited a strong free radical scavenging activity and reducing power determination. However, a gradual increase in the free radical scavenging activity and reducing power determination was obtained with increasing concentrations. The highest radical scavenging activity was shown by the water extract from Galgeuntang (116.93 ${\mu}g$/mL) and the water extract from Cinnamonum cassia Presl. (95.01 ${\mu}g$/mL). These results of phenolic and flavonoid contents of the extracts indicated that the strong radical scavenging activity of the Cinnamonum cassia Presl. extract might be in part due to the phenolic compounds. The correlation coefficient between TPC and DPPH ($r^2$ = 0.9312), TFC and DPPH ($r^2$ = 0.9677), showed positive correlation among total phenolic/flavonoid contents and antioxidant activity. These results suggest that Galgeuntang has a potential antioxidant activity.

• The Korean Journal of Pesticide Science
• /
• v.7 no.2
• /
• pp.92-99
• /
• 2003

A 96-well plate was applied to determine the DPPH free radical scavenging activity using 107 plant-specific enzyme inhibitors and 100 unknown plant-originated extracts. The final optimum volume was $250{\mu}L$ containing $100{\mu}M$ DPPH ethanolic solution at pH 7.8. In this condition, the radical scavenging activities were significantly increased by two known antioxidants consisting of ascorbate and a-tocopherol in a concentration-dependent manner. Among the 107 inhibitors, ampicillin and gallic acid showed 90.2% and 92.6% antioxidant activity at $100{\mu}M$, respectively, and these results were consisted with previous findings. In the tested 100 natural materials at $50{\mu}g/mL$, antioxidant activity of AT-407 resulted in the highest of 90.1%, and 10 extracts including AT-388 and AT-443 showed over 70%. Our results suggest that the use of 96-well plate for determining DPPH free radical scavenging activity would be a suitable method to select antioxidant-like substances of both synthetic compounds and natural products.

• Food Science and Preservation
• /
• v.9 no.2
• /
• pp.253-259
• /
• 2002

The antioxidative and free radical scavenging activity of water extracts of dandelion were investigated. Antioxidative and radical scavenging activity were assessed by means of different tests; inhibition of peroxidation on linoleic acid model system, scavenging DPPH radical, scavenging of hydroxyl radical by chemiluminescence assay, scavenging of superoxide anion radical by EPR spectroscopy and scavenging of hydrogen peroxide. The leaf extract showed strong antioxidant activity in linoleic acid system. The antioxidant activity of water extracts of dandelion increased with increasing concentrations of extracts. The scavenging activity of the dandelion extracts, on inhibition of the DPPH radical, was related to the reaction time. Hydroxyl radical were generated by lenten reaction and dandelion extract was found to scavenge OH˙in a concentration-dependent manner. The water extract of leaf had effective scavenging activities on hydrogen peroxide and superoxide anion radical. From the these data, it is evident that water extract of dandelion leaf is an effective scavenger for OH˙, O$_2$¨, DPPH˙, hydrogen peroxide. And, the antioxidative effect observed is believed to be partly due to this radical scavenger activity.

• Journal of Life Science
• /
• v.11 no.6
• /
• pp.509-516
• /
• 2001

Enzymes and non-enzymatic antioxidants are involved in defense of oxgen free radical intermediates in all aerobic cells. The non -enzymatic antioxidants and antioxidant enzyme from the extracts of Solanum nigrum L. known to be anticancer medicinal plant were examined in other to utilize the discovery in natural products as cancer chem-opereventive agents. The DPPH(1,1-diphenyl-2-picryl-hydrazyl) free radical scavening activity on plant position of Solanum nigrum L. was the highest in root, with stem, whole plant, seed, leaf and flower, at higher activities respectively. In extraction methods, the DPPH free radical scavenging activity by circulating extraction with 80 % MeOH. The DPPH activity of L6 fraction by LH-20 column chromatography showed about 6.7 times higher than that of ethyl acetate-fraction. These were identified as phenolic compounds such as 2-6-methano-3-benzazocin-11-ol, 2[1H]-phyidinethione and 2-hydroxy -5-methyl-benzaldehyde. Peroxidase(POD) and superoxide dismutase(SOD) activities of stem and root were higher than that of other plant positions and those of plant positions according to growing stage were the highest in 60 days after seeding. The numbers of isozyme pattern of POD and SOD showed 10 hands and 5 bands, respectively, especially, 8 bands of POD and 3 bands of SOC showed a difference according to plant positions.

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

• Korean Journal of Pharmacognosy
• /
• v.41 no.3
• /
• pp.180-184
• /
• 2010

The antioxidant activity of Desmodium oldhami (Leguminosae) was determined by measuring the radical scavenging effect on DPPH (1,1-diphenyl-2-picrylhydrazyl). The methanolic extract of D. oldhami showed the strong antioxidant activity. Five compounds, kaempferol-3-O-rhamnopyranoside (afzeline) (1), quercetin-3-O-[$\alpha$-L-rhamnopyranosyl($1{\rightarrow}6$)-$\beta$-Dglucopyranoside] (rutin) (2), kaempferol-3-O-glucopyranoside (astragalin) (3), genistein-7-O-$\beta$-D-glucopyranoside (genistin) (4), kaempferol-3-O-rutinoside (5) were isolated from the active ethyl acetate soluble fraction of D. oldhami through repeated silica gel and Sephadex LH-20 column chromatography. Among them, compound 2 showed the most significant antioxidative effect on DPPH free radical scavenging test. Compounds 1-5 are reported for the first time from this plant.

• Korean Journal of Plant Resources
• /
• v.19 no.3
• /
• pp.405-410
• /
• 2006

A series of aqueous or methanol extracts from four different Korean salad plants were assayed to determine their allelopathy and antioxidant activity. The extracts applied on filter paper in a Petri-dish bioassay significantly inhibited root growth of against alfalfa (Medicago sativa) seedlings. Leaf extracts from 40 g dry tissue $L^{-1}$ of Aster yomena was most phytotoxic to alfalfa root growth, and followed by that of Cirsium japonicum, Taraxacum officinale, and Ixeris dentate. Methanol extracts of plants dose-dependently increased DPPH free radical scavenging activity in vitro. Antioxidant activity of methanol extracts from the same plant species was investigated, and the result showed high DPPH free radical scavenging activity in Cirsium japonicum, Aster yomena, and Ixeris dentate, however, in Taraxacum officinale was least activity. By means of HPLC analysis, chlorogenic acid, p-coumaric acid, and total phenolics with 7.68, 17.47 and 18.64 mg, $100g^{-1}$, respectively, showed the highest amounts in methanol extracts from Cirsium japonicum leaves. These results suggest that Compositae salad plants contain water-soluble substances with allelopathic potential as well as antioxidant activity.