• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2585-2591
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• 2012

A series of heterocyclic chalcone derivatives bearing heterocycles such as thiophene or furan ring as an isostere of benzene ring were carefully prepared, and the influence of heterocycles on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities was systematically investigated. Structure-activity relationships (SAR) analysis showed that the activities of thiophene ring-containing chalcones were higher than those of furan ring-containing chalcones, and the presence of methyl substituent of heterocyclic ring distinctly affected the activities compared with non-substituted heterocycles in an opposite manner, with the 4'-methyl group of thiophene ring increasing activity and the 3'-methyl group of the furan ring decreasing activity. The distinct isosteric effect of heterocycles (i.e., thiophene or furan ring) on radical scavenging activities of heterocyclic chalones was distinctly demonstrated in our work.

• Korean Journal of Pharmacognosy
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• v.29 no.1
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• pp.28-34
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• 1998

It has been known that diseases related with aging or cancer result, at least in part, from free radicals, and antioxidants may reduce or prevent the abnormalities associated with free radical formation via its scavenging action. Thus, this study was carried out to investigate the antioxidative and antimicrobial activities of nut species for the purpose of developing antioxidant from natural products. Antioxidant activities of four kinds of nuts such as chestnut, groundnut, walnut and acorn were examined by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. The extracts from chestnut hull and acorn barnyard millet showed strong antioxidative activities among 10 samples tested. Because of their highest antioxidative activity among 10 samples, radical scavenging effects of 4 different extract compartments (Hexane, EtOAc, BuOH and $H_2O$ extracts) from chestnut hull and acorn barnyard millet, were further examined by DPPH method. EtOAc and BuOH extracts exhibited antioxidative activities similar to those of natural, tocopherol or synthetic antioxidants, BHA. These findings demonstrates that major fraction of the antioxidative activity of chestnut hull or acorn barnyard millet was the EtOAc and BuOH extract compartments. However, antimicrobial activities against food-related bacteria and yeasts was relatively weak.

• Korean Journal of Acupuncture
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• v.32 no.4
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• pp.169-176
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• 2015

Objectives : This study is to investigate the effects of Rhizoma drynariae aqueous extract(RDA) on cell cytotoxicity, Nitric Oxide (NO) and Prostaglandin $E_2(PGE_2)$ production and 1,1-diphenyl-2-picryl ghdrazyl(DPPH) free radical scavenging capability. Methods : Cell cytotoxicity was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay. The production of NO was measured by Griess assay. The production of $PGE_2$ was measured by immunoassay. And, the anti-oxidant activity was measured by the DPPH method. Results : Cell cytotoxicity in 50, 100, 200 and $400{\mu}g/ml$ RDA did not increase significantly compared to the RDA untreated group. RDA($200{\mu}g/ml$ and $400{\mu}g/ml$) inhibited NO and $PGE_2$ production in lipopolysaccharide-stimulated RAW 264.7 cells. RDA had high DPPH free radical scavenging capability. Conclusions : This study indicates that RDA inhibits NO and $PGE_2$ production in lipopolysaccharide-stimulated RAW 264.7 cells and improve DPPH free radical scavenging capability. RDA may have an anti-inflammation effect and an anti-oxidant activity.

• Natural Product Sciences
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• v.23 no.2
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• pp.75-83
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• 2017

The optimization and microwave assisted extraction of stem bark of Terminalia arjuna, quantitative estimation of the marker compounds arjunic acid and arjunolic acid using HPTLC and the evaluation of free radical scavenging activity has been performed in this study. The central composite design was used for optimization and the values of parameters for optimized batch of microwave assisted extraction were 1000 W (Power), 3 minutes (Time) and 1/120 (Solid/solvent ratio). The solvent system to carry out the HPTLC was toluene: acetic acid: ethyl acetate (5: 5: 0.5) and quantitative estimation was done using standard equations obtained from the marker compounds. The in-vitro free radical scavenging activity was performed spectrophotometrically using ascorbic acid as standard. The value of estimated percentage yield of arjunic acid and arjunolic acid was 1.42% and 1.52% which upon experimentation was obtained as 1.38% and 1.51% respectively. The DPPH assay of the different batches of microwave assisted extraction and marker compounds taken suggested that the marker compounds arjunic acid and the arjunolic acid were responsible for the free radical scavenging activity as the batch having the maximum percentage yield of the marker compounds showed best free radical scavenging effect as compared to standard ascorbic acid. The $IC_{50}$ value of the optimized batch was found to be 24.72 while that of the standard ascorbic acid was 29.83. Hence, the yield of arjunic acid and arjunolic acid has direct correlation with the free radical scavenging activity of stem bark extract of Terminalia arjuna and have potential to serve as active lead compounds for free radical scavenging activity.

• Journal of Acupuncture Research
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• v.20 no.2
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• pp.184-194
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• 2003

Objective : This study was designed fo find out whether Astragali Radix Herbal-Acupuncture Solution(ARHA) can scavenge NO, DPPH and IL-4 or not. Astragali Radix has been clinically used to reforce the depression of immune reponse etc. in Oriental Medicine. Methods : Free radical metabolism seems to occupy a remarkably common position in the mechanisms of ageing and ageing related disease. Oxidative damage to DNA, lipids, proteins and other molecules may contribute to the development of cancer, cardiovascular disease and possibly neurodegenerative disease. The effects of ARHA on NO, DPPH and IL-4 were measured. Results : The followings are the summary of the result; (1) There is a significant scavenging effect of ARHA on NO in 1, $10mg/m{\ell}$ group in after 24hrs. (2) There is no significant scavenging effect of ARHA on DPPH. (3) There is a significant scavenging effect of ARHA on IL-4 in 1, $10,100{\mu}g/m{\ell}$ group. Conclusions : These results suggest that ARHA has significant scavenging effect on NO, IL-4 and not on DPPH. This study shows that ARHA can be used for ageing related disease and further studies are required to investigate the antioxidative effects of it.

• Food Science and Preservation
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• v.11 no.2
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• pp.201-206
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• 2004

The activities of antioxidation and alcohol dehydrogenase in hibitionin methanol extracts of thirty two medical herbs were tested using the method of DPPH activity, nitrite scavenging effect and alcohol dehydrogenase assay in vitro. In DPPH method, Eugenia caryophyllata, Thea sinensis, Paeonia suffruticosa, Alnus japonica showed over 90 % of free radical scavenging activities. The nitrite scavenging ability appeared Zanthoxylum bungeanum, Alnus japonica, Thea sinensis, Hovenia dulcis(cortex) and Illicium verum showed the high value. In connection with in vivo alcohol metabolism, thirteen medicinal herbs were screened for inhibition. As a reasult, we found significant inhibition of ADH by methanolic extracts of Glycyrrhiza uralensis, Pueraria thunbergiana(radix), Alnus japonica. These results indicate that the antioxidative effect was strongly related with alcohol dehydrogenase inhibitor; Thea sinensis and Alnus japonica.

• YAKHAK HOEJI
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• v.45 no.1
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• pp.101-107
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• 2001

Green tea catechins (GTC) and its major component, (-)-epigallocatechin gallate (EGCG) were studied for their protective effects against reactive oxygen species (ROS)-induced oxidative stress. GTC and EGCG skewed the strong antioxidative effects on the lipid peroxidation of ethyl linolate with Fenton's reagent and free radical scavenging effect to DPPH radical generation. They also protected $H_2O$$_2$- or KO$_2$-induced cytotoxicity in CHL cells or mouse splenocytes. These results indicate that GTC and EGCG are capable of protecting the lipid peroxidation, flee radical generation and cytotoxicity induced by ROS. The mechanism of inhibition in ROS-induced cytotoxicity may be due to their antiofidative and free radical scavenging properties. Therefore, GTC and EGCG may be useful chemopreventive agents by protecting the free radical generation which are involved in cancer and aging.

• Korean journal of food and cookery science
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• v.32 no.4
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• pp.441-448
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• 2016

Purpose: This study was conducted to investigate the effect of cabbage powder on the quality characteristics of rice nutritional bars. Methods: In order to analyze quality characteristics, total phenolic content, DPPH free radical scavenging activity, baking loss rate, leavening rate, specific volume, moisture content, color, texture analysis, and sensory evaluations were assessed. Results: The total phenolic content and DPPH free radical scavenging activity of rice nutritional bars significantly increased with an increase in the content of cabbage powder (p<0.05). The baking loss rate, leavening rate, specific volume, and moisture content of the rice nutritional bars were significantly reduced as the amount of added cabbage powder increased (p<0.05). As the concentration of cabbage powder increased, the lightness and redness of the bars' crust and crumbs decreased, while yellowness increased (p<0.05). In texture analysis, the control bars showed the highest hardness values. Adhesiveness, springiness, and cohesiveness values slightly decreased with higher cabbage powder content in the groups with added cabbage powder (p<0.05). When consumer acceptability was measured, rice nutritional bars prepared with 15% cabbage powder showed the highest scores in color, whereas the rice nutritional bars prepared with 20% cabbage powder showed the lowest scores in flavor (p<0.05). In characteristic intensity rating, the taste and off-flavor of rice nutritional bars significantly increased with increasing amounts of cabbage powder (p<0.05). Conclusion: Judging from our results, it can be concluded that the addition of cabbage powder to rice nutritional bars during processing can enhance consumer preference for the bars, total phenolic content, and DPPH free radical scavenging activity.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.271.1-271.1
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• 2003

In order to find the new hepatoprotective agents the preliminary screening of 12 prescriptions which have been used for the treatment of hepatic disease in Oriental traditional medicine has been carried out. Both DPPH free radical scavenging and hepatoprotective effect on tacrine-induced cytotoxicity in Hep G2 cells are performed. (omitted)

• Korean Journal of Pharmacognosy
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• v.34 no.4 s.135
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• pp.324-326
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• 2003

The methanol (MeOH) extract and ist fractions of Taraxacum mongolicum (Compositae) were examined for their scavenging effects on 1,1-diphenyl-2- phenylhydrazyl (DPPH) and superoxide radicals, and hepatoprotective effects on tacrine-induced cytotoxicity in human hepatoma cell line, Hep G2 cells. Both methylene chloride $(CH_2Cl_2)$ and butanol (n-BuOH) soluble fractions of the MeOH extract showed the free radicals scavenging and hepatoprotective effects. From these results, it is suggested that hepatoprotective effect of these fractions partly relies on their free radical scavenging activity.