• Food Science and Biotechnology
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• v.14 no.2
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• pp.177-180
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• 2005

Antioxidant activity of crude extracts from colored sweet potato cultivars by plant parts such as root, stem and leaf was evaluated. The highest TBARS values were obtained from root samples of sweet patato, and followed by stems and leaves, indicating that leaf sample showed the strongest antioxidant activity. Sweet potato cultivars with yellow flesh and leaf part exhibited strong antioxidant activities. Antioxidant activities of leaf and stem extracts were maintained for 21 days and were a little lower than that of BHT. The DPPH radical scavenging activity was the highest in "Sinhwangmi" leaf, and followed by "Jami" root. Chlorogenic acid was detected as the most abundant antioxidant substance among all fractions. These results suggest that the antioxidant activity of sweet potato differs depending on plant part and cultivar.

• The Korean Journal of Food And Nutrition
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• v.24 no.1
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• pp.94-100
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• 2011

This study identified the formula of the antioxidant substance separated from the ethyl acetate and the butanol extract and tested the antioxidant properties with the electron donating ability(EDA). Each phase with the fractionated methanol extract from mulberry leaf was screened in advance for the antioxidant substance with EDA. As the result, activity appeared in the ethyl acetate and butanol phase and the antioxidant component was separated. As the consequence, 2 components from the ethyl acetate phase and 1 from the butanol phase were separated, among which the structures of the components from ethyl acetate were determined by wogonin and linarin, whereas the structure of the component from the butanol phase was determined by pectolinarin. In the screening of antioxidant activity by the scavenging effect of the DPPH radical, the wogonin and linarin components from ethyl acetate phase showed more powerful antioxidant property than the component from butanol. The results from this study indicate that the chemical compound separated from the ethyl acetate extract has more powerful antioxidant property than the one separated from the butanol extract. The components separated from the ethyl acetate extract were wogonin and linarin, which are flavonoids, whereas the component from butanol was pectolinarin. Therefore, this study suggested that the feasibility of mulberry leaf as a functional food additive and its value as a natural antioxidant is very high.

• The Korean Journal of Food And Nutrition
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• v.14 no.6
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• pp.527-531
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• 2001

In order to isolate antioxidant substances from Rhus verniciflua (RV) , the dried stem bark was extracted with water. The crude water extracts was purified by using HPLC method with a DEAE (anionic type) , CN and ODS column. The purified compound remained stable at pH 3.0∼6.0. but unstable above pH 6.5. It was stable at 100$^{\circ}C$ for 4 hours, but still had about 80% of residual activity after treatment at 100$^{\circ}C$ for 5 hours. In antimicrobial test, no inhibition was observed against Gram-positive and negative bacteria. This compound was stronger than that of commercial antioxidant showed that DPPH test, such as BHT, BHC at the same concentration (20 $\mu\textrm{g}$/ml) .

• YAKHAK HOEJI
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• v.48 no.4
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• pp.236-240
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• 2004

Acanthopanax species (Araliaceae) traditionally has been used as analgesics, stimulant of immune system, and replenishment of body functions. Acanthopanax divaricatus var. albeofructus is indigenous plant to Korea. The antioxidant activities of compounds from A divaricatus var. albeofructus were determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and thiobarbituric acid reactive substance (TBARS) assay on human plasma low-density lipoprotein (LDL). The triterpenoid and lignan constituents from this plant showed antioxidant activities and the lignan, l-sesamin exhibited the most potent antioxidant activity in Cu$^{2+}$ -induced LDL oxidation.n.

• Preventive Nutrition and Food Science
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• v.16 no.2
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• pp.127-134
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• 2011

The purpose of this study was to purify antioxidant substances from steamed squid extract (SSE). The yield of SSE was 8% by dry weight. The approximate compositions of SSE proteins, lipids, moisture, carbohydrate and ash were 64.95%, 1.69%, 7.23%, 4.44% and 21.69%, respectively. The major amino acids in SSE were taurine (29.17%), glycine (20.33%), alanine (12.51%), and glutamic acid (9.83%). Antioxidant activities were evaluated using 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging activity, which was measured as 24.7% at 1.0 mg/mL. Four SSE fractions were isolated by Sephadex G-25 gel chromatography; the F2 fraction showed the highest DPPH radical scavenging activity. The F2 fraction was separated by reverse-phase high performance liquid chromatography (HPLC) using an octadecylsilane (ODS) column, yielding a purified antioxidant substance with a DPPH radical scavenging activity of 64.41% at 1.0 mg/mL, representing a 2.64-fold increase in the scavenging activity of SSE purified by the 3-step procedure. The amino acid compositions showed that purified SSE was rich in taurine, glycine, glutamic acid and alanine. The purified SSE significantly elevated 2',7'-dichlorodihydrofluororescein diacetate (DCFH-DA) fluorescence probe, which confirms its effective radical scavenging potential in cellular ROS. In addition, the SSE significantly inhibited oxidative damage of purified genomic DNA. These results suggest that a purified antioxidant substance from SSE can be used as a potential natural compound-based antioxidant in the functional food and pharmaceutical industries.

• Journal of Nutrition and Health
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• v.38 no.1
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• pp.67-75
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• 2005

This study was performed to examine the change of lipid metabolism and immune function caused by antioxidant material in hypercholesterolemic elderly women (serum total cholesterol $\geq$200 mg/dI). The subjects were 51 elderly women aged over 60 yrs. They were divided into antioxidant nutrients complex group (n = 25) and spirulina group (n= 26). Antioxidant nutrients complex (1 capsule/day) and spirulina (7.5 mg/day) were used for intervention for 8weeks. All the subjects were fully informed the purpose of study and gave written consents to participate in this study. Dietary intakes, anthropometric indices and blood assessment for lipid, immune function and antioxidant status were measured before and after supplementation. Either antioxidant nutrients complex or spirulina supplementation for 8weeks resulted in improved antioxidant status evidence by increased TAS (total antioxidant status) and decreased TB-ARS (thiobarbituric acid reactive substance) . This intervention led to decreased serum levels of total cholesterol, LDL-cholesterol, oxLDL, apolipoprotein B, IL-6 and IL-6 production by peripheral blood lymphocyte. In conclusion, the lipid profiles, immune function and antioxidant capacity were improved after either antioxidant nutrient complex or spirulina supplementation for hypercholesterolemic women. Therefore, improving antioxidant status using supplemen-tation could provide means of controlling cardiovascular disease in Korean elderly people.

• Journal of Korean Biological Nursing Science
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• v.10 no.1
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• pp.1-10
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• 2008

Purpose: The purpose of this study was to investigate the cerebral infarction size, antioxidant enzyme activities and lipid peroxidation changes after 6 weeks of dietary soybean protein intake in a rat focal brain ischemia model. Method: Weaning Sprague-Dawley rats were fed with either modified AIN-93G diet containing casein 20% (control), 20% soybean protein isolate-based diet (S20), or 40% of soybean protein isolate-based diet (S40) for 6 weeks. The animals were subject to right middle cerebral artery occlusion for 2 hr. After 24 hr of recirculation, the rats were sacrificed. Antioxidant enzymes activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) and thiobarbituric acid reactive substance (TBARS) level in the right brain were also measured. Result: There were no significant differences in the right cortical infarction volume, TBARS level, SOD and CAT activities among the three groups whereas the GPx activities of the S20 group were significantly higher than those of the control group (p=.02). Conclusion: Our results suggest that 20% of soybean protein may have a modulating effect on GPx and possibly have some protective effect against oxidative stress although it may enough to decrease cerebral infarction volume in rat focal brain ischemia model.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.2
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• pp.471-476
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• 1999

The effects of total dietary restriction(100% restriction of energy intake) on thiobarbituric acid reactive substance(TBARS) contents and intracellular antioxidant enzymes activities in the liver and kidney of young male Sprague Dawley rats were studied. The TBARS contents were reduced in both liver and kidney, up to 77% and 79% of the control rats, fed ad libitum, respectively at 7 days after dietary restriction . Superoxide dismutase(SOD) activities in the liver and kidney of rats were increased significantly by total dietary restriction. However, the activity of catalase in kidney was decreased 27% at 6 days after dietary restriction, but this enzyme activity did not change in liver. The changes of glutathione peroxidae(GSHPx) and catalase activities in the liver and kidney of rats with dietary restriction were not significant. These result suggested that dietary restriction reduce the free radical induced by tissue damage, as determined by TBARS content, in both the liver and kidney but the changes of activities of antioxidant enzymes may not be a contributory factor in reducing oxidative damage to tissue.

• KSBB Journal
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• v.24 no.2
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• pp.189-194
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• 2009

In this work, antioxidant substance homoorientin from Pseudosasa japonica and Phyllostachys bambusoides leaves wereextracted using ultrasonic system, and analyzed by reversed-phase high performance liquid chromatography (RP-HPLC) on-line ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) antioxidant screening method. Also, the various experimental variables were the frequency and time of ultrasonic system. From the results, homoorientin was high extracted at the experimental condition of low frequency 35 kHz and time 60 min. And the content of homoorientin in Phyllostachys bambusoides was remarkably higher than that in the Pseudosasa japonica extract.

• Microbiology and Biotechnology Letters
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• v.11 no.3
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• pp.201-204
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• 1983

Antioxidant, tentatively named PA-29B substance was isolated from the fermentation broth of rare Actinomycetes. It was isolated by means of silica gel column chromatography and obtained as colorless plates, mp 155-157$^{\circ}C$. The structure of PA-29B substance was assigned to be $\alpha$-phenyl acetamide by $^1$HNMR spectrometer and mass spectrometer.