• KSBB Journal
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• v.19 no.1
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• pp.57-61
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• 2004

A peroxynitrite is formed when superoxide and nitric oxide exist at near eqimolar ratio in biological systems. Although not a free radical by chemical nature, peroxynitrite is a powerful oxidant having a wide array of tissue damaging effects ranging from lipid oxidation and inactivation of enzymes and ion channels through protein oxidation and nitration to inhibition of mitochondrial respiration. During our search for new antioxidizing components from natural resources, twenty salt marsh plants were screened for their ONOO and DPPH radical scavenging activities. Among them, methanol extract of Rosa rugosa, lxeris tamagawaensis, Erigeron annus, Tetragonia tetragonoides, Imperata cylindrica, and Suaeda japonica inhibited more than 85% of peroxynitrite produced by 3-morpholinsydnonimine (SIN-1) at a concentration of 5 $\mu\textrm{g}$/$m\ell$. In addition, Rosa rugosa, Artemisia capillaris, Erigeron annus and Ixeris tamagawaensis showed significant scavenging effect against DPPH (1,1-diphenyl-2-picrylhydrazyl radical).

• Preventive Nutrition and Food Science
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• v.11 no.2
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• pp.171-175
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• 2006

Alnus japonica Steud (Betulaceae) has long been used as a Korean traditional medicine for gastric disorders, hepatitis, and fatty liver. As a part of our study on the identification of secondary metabolites of naturally occurring bioactive compounds, we isolated 1,7-bis(4-hydroxyphenyl)-3,5-heptanediol(1), 5-hydroxy-1,7bis(4-hydroxyphenyl)-3-heptanone(2), 5,3'-dihydroxy-7,4'-dimethoxyflavone(3) and 3,5,7,3',4'-pentahydroxyflavone(4) from the dichloromethane and ethylacetate-soluble fractions of Alnus japonica Steud. These compounds showed significant antioxidant activity in a concentration-dependent manner. The $IC_{50}$ values of compounds 1, 2, 3 and 4 were 30.1, 37.4, 20.2 and 13.7 ${\mu}g/mL$, respectively, through the scavenging capacity of 1,1-diphenyl-2-picrylhydrazyl radical assay.

• Archives of Pharmacal Research
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• v.26 no.6
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• pp.458-462
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• 2003

The antioxidant activity of the stem bark from Albizzia julibrissin was evaluated for its potential to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, to inhibit the generation of the hydroxyl radical ($\cdot OH$), total reactive oxygen species (ROS) and to scavenge authentic peroxynitrites ($ONOO^{-}$). The methanol extract of A. julibrissin exhibited strong antioxidant activity in the tested model systems. Therefore, it was further fractionated using several solvents. The antioxidant activity of the individual fractions were in the order of ethyl acetate (EtOAc) ＞ n-butanol (n-BuOH) ＞ dichloromethane ($CH_2 CI-2$) ＞ and water ($H_2O$). The ethyl acetate soluble fraction, which exhibited strong antioxidant activity, was further purified by repeated silicagel, Sephadex LH-20 and RP-18 gel column chromatography. Sulfuretin (1) and 3 ,4 ,7-trihydroxyflavone (2) were isolated as the active principles. Compounds 1 and 2 exhibited good activity in all tested model systems. Compound 1 exhibited five times more inhibitory activity on the total ROS than Trolox. Compound 2 showed six times stronger DPPH radical scavenging activity than L-ascorbic acid. These results show the possible antioxidant activity of the A. julibrissin crude extract and its major constituents.

• Journal of Life Science
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• v.23 no.3
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• pp.361-367
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• 2013

Hizikia fusiformis has been widely used in Oriental herbal medicine and health food. To identify antioxidation properties that contain natural bioactive substances, we investigated the distribution of active compounds existing in batches of organic solvent fractionation. A dried form of H. fusiformis was subjected to sequential fractionation using n-hexane, ethyl acetate, n-BuOH, and aqueous n-BuOH. The results showed that among the four isolated fractions, the n-BuOH fraction showed the highest antioxidation activities. The n-BuOH fraction was applied to reserve-phase silica gel column chromatography, which produced three fractions: BA, BB, and BC. Among these fractions, BB showed the highest antioxidation activities, which increased in a concentration-dependent manner. At a concentration of 1.0 mg/ml n-BuOH fraction, the activities of DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging and reducing power were approximately $45{\pm}0.14%$ and $1.34{\pm}0.23$, respectively. In addition, the activities of ${\beta}$-carotene-linoleic acid, hydrogen peroxide scavenging, and ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)) radical scavenging were $76{\pm}0.12%$, $82{\pm}0.06%$, and $65{\pm}0.17%$, respectively. These findings suggest that the BB fraction contains potent antioxidation properties and that it could be used in the production of natural and functional foods.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.43 no.4
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• pp.337-347
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• 2017

In this study, free radical scavenging activity and enzyme-linked immunosorbent assay (ELISA) experiments were carried out using Dioscorea japonica (D. japonica) and Chenopodium album (C. album) extracts to evaluate their anti-oxidative and anti-inflammatory effects. In the free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity, $EC_{50}$ of D. japonica and C. album were measured as 2.386 and 0.524 mg/mL, respectively. The free radical scavenging activity of the mixed sample of D. japonica and C. album was the highest when the D. japonica and C. album ratio was 2 : 1. The IL-6 and $TNF-{\alpha}$ ELISA assay showed that IL-6 in mouse spleen cells treated 1 mg/mL of samples, D. japonica and C. album decreased the production of IL-6 concentration by 27.17%, 72.30%. In the case of $TNF-{\alpha}$, D. japonica and C. album decreased 61.97% and 77.85% of $TNF-{\alpha}$ production, respectively. Through these results, we confirmed that D. japonica and C. album have antioxidant and anti - inflammatory effects and could be applied to natural medicine cosmetic having anti - inflammatory effects.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.343-346
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• 2005

The isolated strain, SC2-1 was Gram-positive, catalase positive, facultatively anaerobic, oxidase negative, motile and small rods. The strain utilized sucrose, dextrose, fructose, mannitol and maltose as a sole carbon and energy source and sodium chloride required for the bacteria growth. The radical scavenging activity of the culture supernatants was determined by DPPH (1,1-diphenyl-2-picrylhydrazyl) method. This bacterium was identified based on cellular fatty acids analysis and 16S rDNA sequencing then named Exiguobacterium sp. SC2-1. The optimum culture conditions for production of antioxidant were $25^{\circ}C,$ pH 7.8 and NaCl concentration were 4%. The modified optimal medium compositions were maltose 2.5% (w/v), yeast extract 1.5% (w/v) and $KH_2PO_4$ 0.05% (w/v). Free radical scavenging activity of under optimal culture conditions were 93%.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.122-122
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• 2012

The aims of this study were to examine the efficacy of phytochemical compounds of colorants as anti-oxidant agent. The bioactive properties of natural colorants were studied by total phenolic contents, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and anti-bacterial activity in Escherichial coli. The concentration ($IC_{50}$) of various extracts from colorants required to exert 50% reducing effect on DPPH radical were found to be 0.007-4 mg/ml. Especially, the gallnut (Schlectendalia Chinensis) displayed remarkable effect of DPPH as compared to positive control ascorbic acid. The total phenolic contents (TPC) and restraint of E coli. also analyzed. It was found that gallnut extracts effectively inhibited DPPH radical at a concentration below 0.01 mg/ml. Natural colorant extracts could be of good resources as anti-oxidant and anti-bacterial agents. The results suggest that our study may contribute to the development of natural and functional materials with potential application to reduce oxidative damage.

• Korean Journal of Food Science and Technology
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• v.32 no.2
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• pp.448-453
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• 2000

During the screening of inhibitors of caspase-3 induction in U937 human monocytic leukemia cells from natural sources, Petasites japonicum, which showed a high level of inhibition was selected. The inhibiting compound was purified from the methanol extract by Sephadex LH-20 column chromatography and HPLC. The inhibitor was identified as [3-(3,4-dihydroxyphenyl)-2-oxopropyl]ester, petasiphenol, by spectroscopic methods of UV, EIMS, $^1H-NMR$, $^{13}C-NMR$ and HMBC. It showed a caspase-3 inducing inhibitory activity at $8\;{\mu}g/ml$ of $IC_{50}$ value with DNA fragmentation inhibition in U937 human leukemia cells. It also showed a free radical scavenging ability of 1,1-diphenyl-2-picrylhydrazyl.

• 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 ($48.50\;{\mu}M$, $K_m$).

• Natural Product Sciences
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• v.22 no.3
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• pp.216-219
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• 2016

The microbial transformation of anthranilic acid (1) by the marine-mudflat-derived fungus Thielavia sp. produced an antibacterial polycyclic quinazoline alkaloid, thielaviazoline (2). The stereostructure of the metabolite was assigned based on detailed spectroscopic data analyses including comparison of the NMR ($^1H$ and $^{13}C$) data with those of reported compound (2). Compound 2 displayed in vitro antimicrobial activity against methicillin-resistant and multidrug-resistant Staphylococcus aureus (MRSA and MDRSA), with minimum inhibitory concentrations (MICs) of 6.25 and $12.5{\mu}g/mL$, respectively. Compound 2 also showed potent radical-scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) with an $IC_{50}$ of $11{\mu}M$, which was more active than the positive control, L-ascorbic acid ($IC_{50}$, $20.0{\mu}M$).