• Bulletin of the Korean Chemical Society
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• v.31 no.9
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• pp.2557-2560
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• 2010

To assay for antioxidant capacity of natural products considered important in producing human health benefits, a practical and economical method using pellet techniques was developed. A standard visualizing reagent, 1,1diphenyl-2-picryl-hydrazyl (DPPH), was mixed with a water-miscible polyvinyl alcohol (PVA), serving as a solid phase support for the DPPH reagent. A DPPH pellet was prepared by dropping a small volume of the DPPH solution onto PET film, and drying in an oven. The PVA-based DPPH pellet was dissolved into water, in which the water-miscible PVA plays as a non-ionic surfactant to help the DPPH reagent to be dissolved into the solvent. Using the DPPH assay, the antioxidant capacity of water-soluble extracts of black soybean, barley, green tea, and green gram was examined. Among the natural products tested, green tea showed the highest antioxidant capacity. This PVA-based DPPH antioxidant assay can be further applied in the natural food, raw plant material, and health product inspection field.

• Culinary science and hospitality research
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• v.13 no.4
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• pp.178-185
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• 2007

The antioxidant activities of the bread made from waxy black rice flour(WBRF) and wheat flour were investigated. The waxy black rice bread was manufactured with 10, 20, 30, or 40% waxy black rice flour(w/w). As the additive amount of WBRF were increased, DPPH(1,1-diphenyl-2-picryl-hydrazyl) radical scavenging activity and TEAC(trolox equivalent antioxidant capacity) were also increased. WBRF group showed the higher activity than the control group in DPPH radical scavenging activity and TEAC. The group with 10% WBRF added was not significantly different from the control group in metal chelating activity, but over 20% of addition, it had the higher metal chelating activity than that of the control group.

• The Korea Journal of Herbology
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• v.22 no.4
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• pp.81-86
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• 2007

Objectives : The purpose of this study is to examine the antioxidant activity in the germ cells of the extract of Rehmanniae Radix Preparat (RR). Methods : The extract was studied for diphenyl-picryl-hydrazyl (DPPH) radical scavenging activity, GC-1 cell viability by a modified MTT assay, the effects on H2O2-induced cytotoxicity by MTT assay and lipid peroixidation by malondialdehyde (MDA) formation, respectively. Results : The results showed that the extract scavenged DPPH radical in a dose-dependent manner by up to 43.1%. The extract at concentrations of 100 ${\mu}g/ml$ showed peak level of 136.5% in growth of GC-1 cell. The hydrogen peroxide-induced cytotoxicity was blocked by the extract at concentrations of 10, 50 and 100 ${\mu}g/ml$. The extract (50 and 100 ${\mu}g/ml$) also displayed a dose-dependent reduction of MDA formation on hydrogen peroxide-induced lipid peroxidation. Conclusions : In conclusion, the extract of Rehmanniae Radix Preparat has strong antioxidant activity.

• Korean journal of applied entomology
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• v.61 no.4
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• pp.669-673
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• 2022

To evaluate biological activity of honeydew honey produced by Apis mellifera L. in Korea, we measured antioxidant activity by using DPPH (1,1-diphenyl-2-picryl hydrazyl), ABTS [2,2-azobis(3-ethylbenzothiazoline-6-sulfonate)], FRAP (Ferric reducing antioxidant power), and total polyphenol content assays. Korean honeydew honey respectively scavenged 26% and 86% of DPPH and ABTS radicals at the highest concentration of 10 mg/mL. In the result of FRAP assay, Korean honeydew honey showed activity (126 µM of FRAP value) to reduce Fe³⁺ to Fe²⁺. Total polyphenol content was 73.41 mg GAE/kg. Korean honeydew honey exhibited excellent antioxidant activity due to having high radicals scavenging ability and reducing power of ferric ion as well as the presence of phenolic compounds. These findings suggest that Korean honeydew honey has great potential as a functional food material.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.3
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• pp.427-432
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• 2005

This study was performed to investigate the effect of natural plant extracts on acetylcholinesterase (AChE) activity and the free radical scavenging activity. The methanolic extracts of plants were tested for AChE inhibitory activity using Ellman's colorimetric method in 96-welled microplates and antioxidant activity as the scavenging effect of 1, 1-diphenyl-2-picryl hydrazyl radical (DPPH). The results showed that AChE activities were inhibited (about 20-30%) in whole plant extract of Daucus carota var. sativa, Hypericum erectum and Fragaria yezoensis. AChE activities were inhibited (about 32-34%) in stems extract of Gingko biloba and leaves extract of Rhododendrondron yedoensa var. poukhanense. Fruit extract of Zanthoxylum schinifolium inhibited (about 18%) AChE activity. And the DPPH scavenging effects as antioxidant activity were similar to L-ascorbic acid in whole plant extract of Fragaria yezoensis and fruits extract of Comus officinalis.

• Journal of Life Science
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• v.27 no.1
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• pp.44-49
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• 2017

Natural anti-oxidative compounds have important disease prevention and food preservation properties, in addition to anti-bacterial, anti-inflammation, anti-cancer, and skin whitening effects. High-performance liquid chromatography (HPLC), with an ultra vilolet (UV) detector coupled to a reverse phase C18 column and an online measurement system for 1, 1-diphenyl-2-picryl hydrazyl (DPPH) radicals, was used to search for potent antioxidative compounds in crude extracts. The online HPLC-DPPH assay was then applied to confirm antioxidative compounds in water extracts from Radix of Pueraria lobata, Rhizoma of Zingiber officinale, Fructus of Chaenomeles sinensis, Cortex of Ulmus pumila, and Radix of Astragalus membranaceus. To determine the yields of the extracts, the Brix% of each extract solution was measured using a refractometer. When the relative DPPH radical scavenging ability values of the water extracts were compared with those of a positive control (ascorbic acid), the water extracts of P. lobata, C. sinensis, and U. pumila were 7.77%, 4.71%, and 4.19%, respectively. The results suggest that this method provides a useful assay for rapid measurement of DPPH radical scavenging abilities and conformation of antioxidative compounds in natural products. Moreover, it can reduce the time spent on the separation of active compounds from natural materials, such as medicinal plants, in addition to the use of reagents for separation.

• Toxicological Research
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• v.34 no.1
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• pp.31-39
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• 2018

The objective of this study was to evaluate the antioxidant and anti-aging effects of marigold methanol extract (MGME) in human dermal fibroblasts. Total polyphenolic and flavonoid contents in MGME were 74.8 mg TAE (tannic acid equivalent)/g and 85.6 mg RE (rutin equivalent)/g, respectively. MGME ($500{\mu}g/mL$) increased 1,1-diphenyl-2-picryl hydrazyl (DPPH) and 2,2'-azino-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical-scavenging, and superoxide dismutase (SOD)-like antioxidant activities by 36.5, 54.7, and 14.8%, respectively, compared with the control. At $1,000{\mu}g/mL$, these activities increased by 63.7, 70.6, and 20.6%, respectively. MGME ($100{\mu}g/mL$) significantly increased the synthesis of type 1 procollagen by 83.7% compared with control treatment. It also significantly decreased Matrix Metalloproteinase-2 (MMP-2) activity and MMP-1 mRNA expression by 36.5% and 69.5%, respectively; however, it significantly increased laminin-5 mRNA expression by 181.2%. These findings suggest that MGME could protect human skin against photo-aging by attenuating oxidative damage, suppressing MMP expression and/or activity as well as by stimulating collagen synthesis.

• Natural Product Sciences
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• v.24 no.2
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• pp.125-131
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• 2018

Berries and branches essential oil of Juniperus phoenicea were obtained by electromagnetic induction heating assisted extraction and by hydrodistillation with a yield varied from ($1.2{\pm}0.3$ to $2.4{\pm}0.7%$) and from ($0.6{\pm}0.1%$ to $1.1{\pm}0.1%$), respectively. forty eight compounds were identified representing (97.2 - 99.7%) of the oil. ${\alpha}$-Pinene (40.3 - 67.8%) and ${\delta}$-3-carene (13.5 - 26.8%) were the main compounds in berries and branches essential oils. Antioxidant activity was evaluated by three means: inhibition of 2, 2-diphenyl-1-picryl hydrazyl (DPPH) free radical, reducing power and ${\beta}$-Carotene/linoleic acid bleaching. The antioxidant activity of essential oils showed $IC_{50}$ ranging from $67.6{\pm}1.02{\mu}g/mL$ to $131.5{\pm}0.8{\mu}g/mL$ for berries and from $98{\pm}1.25{\mu}g/mL$ to $166.8{\pm}0.29{\mu}g/mL$ for the branches. Berries oil show more potent antioxidant activity compared to branches. This result is supported by the three methods investigated in this work.

• Herbal Formula Science
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• v.13 no.2
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• pp.101-110
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• 2005

The present study was conducted to compare antioxidant activity of Cuscutae Semen, Psoraleae Fructus, Cnidii Fructus and Epimedii Herba by DPPH radical scavenging activity. The extract was studied using diphenyl-picryl-hydrazyl (DPPH) for DPPH method. DPPH radical scavenging activity was measured after. .10, 20 and 30 minutes. The extract was tested by 1, 5, 10, 50, 100, 500 and $1000{\mu}g/ml$ concentrations. The results showed that the extract scavenged DPPH radical with time-dependent manner. Also, the extract showed dose-dependent DPPH radical scavenging activity. The extract of Cuscutae Semen, Psoraleae Fructus, Cnidii Fructus and Epimedii Herba scavenged DPPH radical with the IC50 being 2.7, 3.2, 2.9 and 1.1 mg/ml, respectively. In conclusion, the extract of Epimedii Herba, Cuscutae Semen, Cnidii Fructus and Psoraleae Fructus have antioxidant activity for the treatment of male sterility.

• Applied Chemistry for Engineering
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• v.31 no.4
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• pp.398-403
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• 2020

In this study, six kinds of rice grown in Cheongwon area were extracted using glycolytic and proteolytic enzymes, and also antioxidant effects and water holding capacity of rice protein extracts were compared and analyzed. Protein contents of rice cultivars protein extract showed that black rice (BR) extract was the highest at 4,900 ㎍/mL, and flavored brown rice (FBR) extract was the lowest at 3,700 ㎍/mL. 2,2-diphenyl-1-picryl-hydrazyl-hydrate free radical scavenging activity was confirmed the superior activity of more than 80.0% at a concentration of 2 mg/mL with BR and red brown rice (RBR) extracts. 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity at a concentration of 2 mg/mL with BR and RBR extracts was more than 70.0% The water holding capacity for extracts using RBR, red-kerneled brown rice (RKBR), BR and FBR was more than 110.0%. Overall, the rice protein extract using BR has excellent antioxidant and water holding capacity which can be used as a potential skin moisturizer and antioxidant functional cosmetic material.