• Journal of Microbiology and Biotechnology
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• v.19 no.12
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• pp.1573-1575
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• 2009

Bioassay-guided fractionation of the culture broth of Aspergillus sp. FN070449 (KCTC 26428) using a DPPH (2,2-diphenyl-1-picrylhydrazyl) assay led to the isolation of two compounds: reticulone (1) and reticulol (2). Their chemical structures were elucidated on the basis of UV, IR, NMR, and MS spectroscopic analyses. Compound 1 exhibited more potent free radical scavenging activity on $ABTS^{\cdot+}$ (2,2'-azino-bis [3-ethylbenzthiazoline-6-sulphonic acid]) and DPPH radicals than did butylated hydroxyanisole (BHA) and caffeic acid.

• Environmental Engineering Research
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• v.19 no.1
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• pp.41-45
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• 2014

The peels of Carya cathayensis Sarg. (PCCS) were treated under subcritical water conditions ($130^{\circ}C$ to $280^{\circ}C$ for 0 to 120 min). The extract from PCCS included reducing sugar, proteins, and compounds with radical scavenging activity. Addressing the reducing sugar that is a resource of bioethanol, we could maximize the reducing sugar under the subcritical water ($190^{\circ}C$ for 60 min) and obtain 0.24 g/g-sample together with 9.7 units/mg-sample of radical scavenging activity. The obtained extract was estimated to correspond to 1 L of bioethanol/100 g-sample. It was therefore considered that the treatment by subcritical water could yield reducing sugar and natural compounds with radical scavenging activity.

• Environmental Analysis Health and Toxicology
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• v.15 no.1_2
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• pp.7-12
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• 2000

Scavenging effects on paraquat induced toxicity were investigated by using methanol (MeOH) and ethylacetate (EtoAC) extracts of Lonicera japonica. The results are summerized as follows: 1. To Fe(III)-ADP-NADPH induced microsomal lipid peroixdation, MeOH and EtoAC extracts showed antioxidative activiies and inhibition ratio at 100 $\mu\textrm{g}$/$m\ell$ 44.4% and 73.8% respectively 2. To microsomal NADPH dependent cytochrome p -450 reductase in rat liver, MeOH and EtoAC extracts inhibited the enzyme activiies and inhibition ratio were 26.3% and 44.8% respectively. 3. Administration (30 mg/kg, iv) of paraquat to rats caused the marked elevation of GOT, GPT, LDH, ALP in the serum and lipid peroxides in the microsome as compared to the control group. Serum GTP, LDH, ALP and liver microsomal LPO were reduced significantaly by administration of MeOH extract. (1,000 mg/kg), EtoAC extract (40 mg/kg) and Silymarin (150 mg/kg) as compared to the paraquat group. From the results, MeOH and EtoAc exuacts. of Lonicera japonica showed the useful scavenger and reducer on the paraquat induced hepatotoxicty.

• Environmental Mutagens and Carcinogens
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• v.19 no.1
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• pp.34-38
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• 1999

Fumonisin B1 is a secondary metabolite of Fusarium moniliforme, a contaminant of corn and corn product. Fumonisin B1 has been shown to be responsible for major toxicological effects of the fungus in rats, horses, and pigs. Fumonisin B1 induced λ DNA fragmentation, which was increased with incubation time, reducing agent NADPH and metal ion (Cu2+). The DNA damage was inhibited by dimethyl sulfoxide (DMSO) or mannitol as radical scavenger for free radicals. DNA fragmentation, induced by fumonisin B1 in the presence of 1 mM NADPH and 0.1 mM CuCl2, was inhibited by 100 mM DMSO. By the in vitro reaction of fumonisin B1 with supercoiled plasmid pBR322 DNA, plasmid DNA was relaxed, eventually linearized in the agarose gel electrphoresis. From rifampicin sensitive E. coli CSH138 in bacterial mutagenesis system, the rifampicin resistant E. coli mutants were obtained by fumonisin B1. These results suggest that fumonisin B1 may be a possible environmental mutagen in bacterial mutagen assay system.

• Biomedical Science Letters
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• v.12 no.4
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• pp.451-455
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• 2006

It is demonstrated that inorganic mercury has cytotoxic effect on glial cells. Recently, oxygen radicals is involved in methylmercuric chloride (MMC)-induced cytotoxicity. But, the toxic mechanism of MMC is left unknown. The purpose of this study was to examine the cytotoxicity of MMC on $C_6$ glioma cells. The cytotoxicy was measured by cell viability using XTT assay in $C_6$ glioma cells. Colorimetric assay is regarded as a very sensitive screening method for the determination of the cell viability on various agents. In this study, MMC decreased cell viability according to the dose- and time dependent manners after $C_6$ glioma cells were grown with various concentrations of MMC for 48 hours. In the protective effect of allopurinol on MMC-induced cytotoxicity, allopurinol was effective in the prevention of MMC-induced cytotoxicity in these cultures. These results suggest that MMC has highly cytotoxic effect on $C_6$ glioma cells by the decrease of cell viavility, and free radical scavenger such as allopurinol was effective on organic mercury-induced cytotoxicity in these cultures.

• Korean Journal of Pharmacognosy
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• v.33 no.4 s.131
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• pp.359-363
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• 2002

Antioxidant properties of the extracts of Acanthopanax senticosus were investigated. The dried roots, stems or leaves were extracted with hot water or ethanol each. The ethanol extracts exhibited higher potency than aqueous extracts in scavenging free radicals and in inhibiting microsomal lipid peroxidation: the aqueous extracts of stems showed higher anti-oxidant effects than the root extracts. Copper-mediated LDL oxidation was also protected by the ethanol exlracts: antioxidant effects of the extracts tested were stronger than ascorbic acid, but not butylated hydroxytoluene. The activity of angiotensin converting enzyme was effectively suppressed by the aqueous extracts of the stems. However, in vivo antioxidant properties of the ethanol extracts of the stems did not seem to be significant, judged from the lipid peroxide values of serum and liver in normal mice. Thus, the ethanol extracts of the stems were shown to be more potent for protecting biological systems against various oxidant stresses in vitro, but not in vivo.

• Natural Product Sciences
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• v.9 no.4
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• pp.245-248
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• 2003

A phytochemical investigation on the methanolic extract of Cosmos caudatus has led to the isolation of quercetin $3-O-{\beta}-D-arabinofuranoside$ (1), quercetin $3-O-{\beta}-D-rhamnoside$ (2), quercetin $3-O-{\alpha]-D-glucoside$ (3) and quercetin (4). These compounds were shown to be the antioxidative constituents of the plant when evaluated using the ferric thiocyanate (FTC) and thiobarbituric acid (TBA), and radical scavengers based on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assays.

• Toxicological Research
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• v.22 no.1
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• pp.39-45
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• 2006

As the antioxidant and free radical scavenger, glutathione (GSH) participates in the preservation of cellular redox status and defense against reactive oxygen species and xenobiotics. Glutamate-cysteine ligase (GCL; also known as ${\gamma}$-glutamylcysteine synthetase, EC 6.3.2.2) is the rate limiting enzyme in GSH synthesis. In the present study, the accurate method for determination of GCL activity in crude liver extracts was developed by measuring both ${\gamma}$-glutamylcysteine and GSH from cysteine in the presence of glutamate, glycine and an ATP-generating system. We added glycine to promote the conversion of ${\gamma}$-glutamylcysteine to GSH, and to minimize the possibility of ${\gamma}$-glutamylcysteine metabolism to cysteine and oxoproline by ${\gamma}$-glutamylcyclotransferase. We established optimal conditions and substrate concentrations for the enzyme assay, and verified that inhibition of GCL by GSH did not interfere with this assay. Therefore, this assay of hepatic GCL under optimal conditions could provide a more accurate measurement of this enzyme activity in the crude liver extracts.

• Journal of the Korean Wood Science and Technology
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• v.23 no.3
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• pp.23-27
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• 1995

Several characteristic results of physical and optical properties of paper treated by UV light were obtained in the previous papers(Kim et al. 1988). In this paper, folding endurance and brightness of paper prepared by spraying photostabilizer were examined in order to elucidate photodegradation phenomena, UV light absorber and radical scavenger were most effective in preventing of folding endurance decrease. These results may be indicated that depolymerization of cellulose and hemicellulose chains leading to degradation of paper mechanical properties mainly caused by radical reaction. Ineffective hydroperoxide decomposer may be explained because of auto-oxidation reactions before forming stable compound from hydroperoxide.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2005.05a
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• pp.340-343
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• 2005

광촉매 효율을 높이기 위해 WO$_{3}$를 첨가하여 제주에 산재해 있는 스코리아를 지지체로 하여 TiO$_{2}$ 및 WO$_{3}$/TiO$_{2}$ 광촉매를 이용하여 humic acid를 분해시킬 경우 반응영향인자에 따른 분해효율을 구한 결과 다음과 같은 결론을 얻었다. Humic acid의 분해시 Ca$^{2+}$를 첨가하였을 때가 첨가하지 않았을 때 보다 효율이 증대한 것은 이온강도가 증가하여 반발력을 감소하여 분해효율이 증대된 것이다. HCO$_{3}\;^-$를 첨가시 분해효율이 감소하는 것은 HCO$_{3}\;^-$이온이 OH radical scavenger로 작용했기 때문이다.