• Journal of the Korean Applied Science and Technology
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• v.33 no.2
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• pp.324-332
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• 2016

The objective of this study was to investigate the antioxidant activity of Korean yam (Dioscorea batatas $D_{ECNE.}$) by different extraction solvents including 70% methanol, 70% ethanol and chloroform-methanol mixture (CM, 2:1, v/v). Raw yam was analyzed for its color property, total phenol content and antioxidant activity. Yam possessed high $L^*$ value and $H^{\circ}$ value, which were $81.64{\pm}2.59$ and $83.36{\pm}0.15$, respectively. Raw yam was found to have great antioxidant activity evaluated through ABTS [2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] radical scavenging activity, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, reducing power, and ferric reducing antioxidant power. Total phenol contents of various extracts from raw yam increased in the following order: 70% methanol extract ($37.62{\pm}0.88mg\;CAE/g$), 70% ethanol extract ($43.38{\pm}0.66mg\;CAE/g$) and CM extract ($67.17{\pm}0.12mg\;CAE/g$), respectively. The same trend was also could be found in the ABTS radical scavenging activity, DPPH radical scavenging activity and ferric reducing antioxidant power assays. These results implied that Korean yam might play an important role in antioxidation and serve as the bio-health functional food to take a good part in prevention of human diseases and aging.

• Journal of Microbiology and Biotechnology
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• v.22 no.1
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• pp.80-83
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• 2012

The addition of NaBr to the fermentation medium of a marine isolate of the fungus Dothideomycete sp. resulted in induced production of two toluhydroquinone derivatives, 5-bromotoluhydroquinone (1) and 4-O-methyltoluhydroquinone (2), and two known compounds, toluhydroquinone (3) and gentisyl alcohol (4). The structures of 1 and 2 were assigned through the spectroscopic data analyses. Compounds 1-4 showed a potent antibacterial activity against the methicillin-resistant and multidrug-resistant Staphylococcus aureus (MRSA and MDRSA) with MIC (minimum inhibitory concentration) values of 6.2, 12.5, 6.2, and 12.5 ${\mu}g/ml$, respectively. Compounds 1-4 also exhibited a moderate radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) with $IC_{50}$ values of 11.0, 17.0, 12.0, and 7.0 ${\mu}M$, respectively, which were more active than the positive control, L-ascorbic acid ($IC_{50}$, 20.0 ${\mu}M$).

• Natural Product Sciences
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• v.16 no.2
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• pp.68-74
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• 2010

Phytochemical investigation on the ethyl acetate and n-butanol fractions of Moutan Cortex resulted in the isolation and characterization of a new monoterpene glycoside (3) and twenty known monoterpene glycosides (1, 2, 4-21). The structure of 3 was determined by spectroscopic data interpretation and physico-chemical properties. Compounds 1 and 8 presented a remarkable inhibitory activity against lipoxygenase-1 (LOX-1) with $IC_{50}$ values of 45.2 and $37.5\;{\mu}M$, respectively. Compounds 9, 10, 13, 18, 19, and 21 showed significant 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging effect with $IC_{50}$ values of 9.8, 25.5, 6.4, 15.2, 18.7, and $23.7\;{\mu}M$, respectively. Benzoylpaeoniflorin (8), which exhibited the highest inhibitory effect with an $IC_{50}$ value of $37.5{\pm}0.7{\mu}M$, was further analyzed the inhibition kinetics by Lineweaver-Burk plots. Results indicated that 8 is a non-competitive inhibitor, and the kinetic parameter values were estimated to be ($31.04\;{\mu}M$, Ki), ($0.29\;{\mu}M/min$, $V_m$), and ($48.50\;{\mu}M$, $K_m$).

• Food Science and Biotechnology
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• v.18 no.4
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• pp.867-871
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• 2009

Response surface methodology (RSM) was used for the optimization of antioxidant capacity in gardenia extracts. The antioxidant capacities of gardenia fruit extracts were investigated by ferric reducing ability (FRA) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity (RSA) assays. The optimum extraction parameters for the strongest antioxidant capacity were the ethanol concentration (EtOH) of 48.9%, extraction temperature of $72.9^{\circ}C$, and extraction time of 29.9 min. Analysis of variance (ANOVA) showed that the quadratics of EtOH and extraction temperature had highly significant effect on the antioxidant capacity (p<0.001). The antioxidant capacity was correlated with contents of bioactive components [crocin, geniposide, and total phenolic (TP) compounds] in gardenia extracts and mainly attributed to the content of the TP compounds.

• Fisheries and Aquatic Sciences
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• v.18 no.4
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• pp.341-347
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• 2015

We evaluated the biological activities of five water extracts of tissue of the mottled anemone Urticina crassicornis. Most extracts exhibited broad-spectrum antimicrobial activity as determined by ultrasensitive radial diffusion assay (URDA) against gram-positive and -negative bacteria, including a fish pathogen, Aeromonas hydrophila, but no activity against fungi. The activity of the extracts was abolished by tryptic digestion, indicating that protein compounds were responsible for the antimicrobial activity. Furthermore, in a 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging activity assay, only the visceral tissue extract showed activity. However, no extract had hemolytic activity against human red blood cells. Consequently, this study suggests the water-soluble extract of mottled anemone to be a promising source of proteinaceous antimicrobial compounds that can be utilized for development of novel antibiotics.

• Natural Product Sciences
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• v.5 no.2
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• pp.80-84
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• 1999

Peroxynitrite is a cytotoxic intermediate produced by the reaction between the superoxide anion radical and nitric oxide. Flavonoids (afzelin, quercitrin and quercetin 3-O-sambubioside), and chlorogenic acid and its methyl ester obtained from leaves of loquat (Eriobotrya japonica) have recently been shown to scavenge 1,1-diphenyl-2-picrylhydrazyl radical and to inhibit lipid peroxidation in mouse liver homogenate. The aim of this study is to investigate the inhibitory effects of the above components on peroxynitrite produced stimulated by 3-morpholinosydnonimine (SIN-1) to produce superoxide anion radical and nitric oxide at the same time. In addition, the present study tests whether or not the components directly scavenge peroxynitrite itself. The results showed that the components with the aromatic ortho-dihydroxyl groups (catechol) were more potent inhibitors of peroxynitrite formation by SIN-1. In particular, the methyl ester form of chlorogenic acid showed the most potent inhibition. At $5\;{\mu}M$ concentration, the order of minimizing peroxynitrite formation were : methyl chlorogenic acid > quercitrin > quercetin 3-O-sambubioside > chlorogenic acid > afzelin. Authentic peroxynitrite was directly scavenged by the components in a manner similar to peroxynitrite formation by SIN-1. In particular, when compared with penicillamine as a positive control, methyl chlorogenate was as effective in inhibiting peroxynitrite formation and approximately 2 times more effective in scavenging an authentic peroxynitrite. These results demonstrate therefore, that components extracted from the leaves of Eriobotrya japonica effectively scavenged peroxynitrite.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.12
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• pp.1815-1820
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• 2008

The aim of this study was to extract chicken leg bone, which is a by-product of industrial poultry processing, using different heating temperatures (80, 90 and $100^{\circ}C$) and durations (5, 10 and 15 min). The pH value, soluble protein content, peptide content and antioxidative properties, including superoxide anion scavenging ability, 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging ability, reducing capacity and inhibitory activity of linoleic acid peroxidation, were measured. The results showed no significant differences (p>0.05) in pH value among all treatments. Decreased soluble protein content and peptide content were observed in chicken leg bone extract obtained under higher heating temperatures (90 or $100^{\circ}C$) and longer heating durations (10 or 15 min). In antioxidative properties, the extracts which were heated at 90 or $100^{\circ}C$ for 15 min exhibited significantly higher superoxide anion scavenging ability, DPPH free radical scavenging ability, reducing capacity and inhibitory activity of linoleic acid peroxidation (p<0.05).

• Journal of the Korean Wood Science and Technology
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• v.46 no.4
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• pp.346-354
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• 2018

Kemenyan resin from Styrax sumatrana is a unique non-timber forest product (NTFP) native from Sumatera Island, Indonesia. It possesses a wide range of applications in the pharmaceutical, perfume, and cosmetics industries. In this paper, six kemenyan resin samples were investigated to evaluate their free radical scavenging activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) reagent. The kemenyan resin samples, which originated from North Tapanuli, Pakpak Bharat, and Humbang Hasundutan, showed high antioxidant activity with $IC_{50}$ < 16 mg/L. The antioxidant activity of common kemenyan resin constituents, i.e., cinnamic acid, ethyl cinnamate, gallic acid, and vanillin was also investigated as positive control, although they exhibited lower antioxidant activity ($IC_{50}$ < 1000 mg/L), except for gallic acid ($IC_{50}$ = 5,23 mg/L). The total phenolic and flavonoid contents (TPC and TFC) for all samples were 44-66 mg gallic acid equivalents (GAE)/g sample and 143-160 mg quarcetin equivalents (QE)/g sample. The results revealed that kemenyan resin has high potency as an antioxidant and could be used as a natural antioxidant resource.

• Advances in Traditional Medicine
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• v.6 no.3
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• pp.167-173
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• 2006

A growing body of evidence supports lipid peroxidation as having a role in the pathogenesis of liver disease. Although the probable cause of damage to human hepatocytes may be multifactorial, free radicals have been implicated in a variety of liver diseases, particularly in the presence of iron overload and toxic substances such as ethanol. Consequently, antioxidants, particularly those of plant origin such as flavonoids, may help to reduce the risk of developing these diseases. Silybum (S.) marianum, a medicinal plant widely used in traditional European medicine for the treatment of liver disorders, was evaluated for antioxidant activity. Thin layer chromatography and High Performance Liquid Chromatography analyses of crude extract of the plant confirmed the presence of a number of flavonoids reported in the literature. The antioxidant activity of these flavonoids was measured through inhibition of lipid peroxidation and 1, 1-diphenyl-2- picrylhydrazyl radical scavenging. The crude plant extract showed marked antioxidant activity in both assays. These results suggest that S. marianum contains flavonoids with antioxidant activity, capable of inhibiting or scavenging free radicals, thus supporting its traditional use as a hepatoprotective agent.

• Biomedical Science Letters
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• v.13 no.4
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• pp.355-360
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• 2007

In order to evaluate on the cytotoxicity of methyl mercury (MM) and antioxidant effect of phenolic compound, poncirin against MM-induced cytotoxicity, XTT assay was performed to determine the cell viability after human skin fibroblasts (Detroit 51) were grown in the media containing various concentrations of methylmercuric chloride (MMC). And also, the antioxidant effect of poncirin on the cytotoxicity induced by MMC was examined by cell viability and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity in these cultures. MMC decreased cell viability in dose-dependent manner in these cultures and the midcytotoxicity value was determined at concentration of 30 ${\mu}M$ MMC after human skin fibroblasts were treated with $10\sim50{\mu}M$ MMC for 72 hours, respectively. MMC was highly toxic on cultured human skin fibroblasts by toxic criteria. MMC-mediated cytotoxicity was related with oxidative stress by the diminution of toxic effect according to the treatment of vitamin E. In the antioxidant effect of poncirin, it showed vitamin E-like DPPH radical scavenging activity at 90 ${\mu}g/ml$ poncirin and also, remarkably increased cell viability compared with MMC-treated group. From these results, it is suggested that MMC-mediated cytoxicity was highly toxic and was related with oxidative stress in cultured human skin fibroblasts, and also phenolic compound such as poncirin showed the protection on MMC-induced cytotoxicity by antioxidant effect in these cultures.