• 한국응용과학기술학회지
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• 제32권2호
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• pp.312-319
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• 2015

In this study, n-butanol and ethyl acetate extracts were prepared from raw yam (Dioscorea batatas DECNE.). Their antioxidative potencies were investigated employing various in vitro methods, such as ferrous ion chelating, ${\beta}$-carotene bleaching assay, lipid peroxidation inhibition and nitric oxide (NO) radical scavenging and nitrite scavenging activity. The n-butanol fraction was assayed to possess stronger antioxidant activity by ${\beta}$-carotene bleaching assay, lipid peroxidation inhibition and NO radical scavenging activity. However, ethyl acetate extract was more effective in chelating ferrous ion and scavenging nitrite. Based on the results obtained, yam is a potential active ingredient that could be applied in antioxidation as well as bio-health functional food to take a good part in prevention of human diseases and aging.

• 응용화학
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• 제15권2호
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• pp.113-116
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• 2011

A sensitive and selective determination method of Fe(II) ion by luminol-H₂O₂ system using a chelating reagent has been presented. A metal ion-chelating ligand complex such as Fe(II)-diethylenetriamine pentaacetic acid (DTPA) produced higher chemiluminescence (CL) intensity as well as longer lifetime in luminol-H₂O₂ system than metal exist as free ions. Furthermore, the catalytic activity of Cu(II) and Pb (II) complexes with chelating reagents in luminol-H₂O₂ system was lost since chelating reagents act as a masking agent although free Cu(II) and Pb(II) ions have high catalytic activity. On the optimized conditions, the calibration curve of Fe(II) ion was linear over the range from 1.0×10^-7 to 2.0×10^-5 M with correlation coefficient of 0.996. The detection limit was calculated to be 4.0×10^-8 M.

• 한국응용과학기술학회지
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• 제33권2호
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• pp.342-351
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• 2016

The bioactive compound and antioxidant property of Korean yam (Dioscorea batatas DECNE.) were studied using in vitro methods. Yam available in Korea was analyzed for lycopene, chlorophyll a, b, tannin, phytic acid and total saponin contents. 70% Methanol, 70% ethanol and chloroform-methanol mixture (CM, 2:1, v/v) were used to extract yam. Then the antioxidant activity evaluated through ferrous ion chelating activity, ${\beta}$-carotene bleaching method, lipid peroxidation inhibition and nitric oxide (NO) radical scavenging activity. 70% Methanol extract showed the highest ferrous ion chelating activity and NO radical scavenging activity. And CM extract was the most effective in inhibition of linoleic acid peroxidation evaluated by ${\beta}$-carotene bleaching assay and lipid peroxidation inhibition assay. Based on the results obtained, yam is a potential active ingredient that could be applied in antioxidation as well as bio-health functional food to take a good part in prevention of human diseases and aging.

• 약학회지
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• 제50권4호
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• pp.228-233
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• 2006

Matrix metalloproteinase-2 is known to be involved in pathological processes such as tumor invasion or rheumatoid arthritis. A soil microorganism producing siderophore under low iron stress $(up\;to\;5\;{\mu}m\;of\;iron)$ was identified as Burkholderia sp. Hydroxamate type siderophore produced by Burkholderia sp. CAS-5 was partially purified. MMP inhibitory activity of siderophore was confirmed by gelatin zymography. The $Zn^{2+}-chelating$ activity of siderophore correlated with the inhibition of MMP-2 activity.

• 한국응용과학기술학회지
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• 제32권3호
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• pp.363-371
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• 2015

n-Butanol and ethyl acetate extracts of thermal treatment yam (Dioscorea batatas $D_{ECNE.}$) belonging to the family Dioscoreaceae were measured for their radical scavenging activity and lipid peroxidation inhibition ability. In this study, ethyl acetate extract showed the most potent antioxidant activity evaluated by ferrous ion chelating activity and NO radical scavenging activity. Nevertheless, n-butanol extract was more effective in inhibiting linoleic acid peroxidation. A significant difference between n-butanol extract and ethyl acetate extract in nitrite scavenging activity ${\beta}$-carotene bleaching assays could not be found. Also, the results of this study showed that thermal treatment yam could be used as easily accessible source of natural antioxidants and as a possible food supplement.

• 한국응용과학기술학회지
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• 제32권2호
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• pp.302-311
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• 2015

To better investigate the antioxidative property of thermal treatment yam (Dioscorea batatas DECNE.) in Korea, some established methods were used. 70% Methanol, 70% ethanol and chloroform-methanol (CM, 2:1, v/v) extracts were collected. 70% Methanol extract exhibited stronger antioxidative activity evaluated by ferrous ion chelating activity, NO radical scavenging activity and ${\beta}$-carotene bleaching assays. On the contrary, CM extract was the most effective in inhibiting linoleic acid peroxidation. Yam available in Korea was also analyzed for its bioactive compounds such as lycopene, chlorophyll a, b, tannin, phytic acid and total saponin contents. Total saponin was abundant in thermal treatment, which determined to be $42.52{\pm}1.88mg/g$. Based on the results obtained from this study, thermal treatment yam could be used as natural antioxidant source due to its high antioxidant activity and bioactive compound contents.

• Journal of Applied Biological Chemistry
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• 제44권2호
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• pp.71-76
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• 2001

Methanol extract and solvent fractions of Aster scaber Thunb. were tested to elucidate antioxidative characteristics in vitro. Methanol extract showed strong inhibition on linoleic acid autoxidation and conjugated diene production. Hexane and diethyl ether fractions showed stronger chelating effect on $10^{-4}M\;FeCl_3$ than the other fractions. Butanol fraction had the strongest capacity on $10^{-3}M\;CuSO_4$ similar to ${\alpha}$-tocopherol. Synergistic effect of butanol fraction with histidine, methionine, and lysine on linoleic acid autoxidation had been observed. Contents of total phenol, vitamin E, vitamin C, and carotenoid were evaluated. From the results, Aster scaber Thunb. could be expected to play a role as an antioxidant in vivo.

• 한국염색가공학회지
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• 제27권1호
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• pp.62-69
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• 2015

To improve the color stability of the bioplastic containing sorghum extract, sorghum extract was chelated by a metal ion. The chelating activity was quantitatively evaluated under the various conditions. Chelation of sorghum extract by Cu(II) was determined by reaction with pyrocatechol violet, whereas Fe(II) chelation was investigated by forming complexes with ferrozine. Chelation of sorghum extract was increased rapidly with increasing concentrations of metal salt and sorghum extract. At a 0.1g/L metal salt addition level, the chelating activity of Fe(II) and Cu(II) were 66.7% and 54.2%, respectively. According to the chelation pH conditions, the sorghum extract was chelated almost 100% by Fe(II) above the pH 6.5. It was confirmed that Fe(II) was a strong chelator of sorghum extract than Cu(II). The sorghum extract chelated with metal salt exhibit higher thermal stability. The bioplastic containing chelated sorghum extract showed relatively less color change than the control.

• Preventive Nutrition and Food Science
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• 제21권2호
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• pp.110-116
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• 2016

This study was performed to evaluate and compare the antioxidant substance content and antioxidant activities of white (Superior) and colored (Hongyoung, Jayoung, Jasim, Seohong, and Jaseo) potatoes. The potatoes were extracted with 80% ethanol and were evaluated for the total polyphenol, flavonoid, and anthocyanin contents and for 1,1-diphenyl-2-picrylhydrazyl (DPPH)/2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity, reducing power, and ferrous metal ion chelating effect. The total polyphenol, flavonoid, and anthocyanin contents of Hongyoung and Jayoung were higher than white and other colored potatoes. All colored potato extracts, except for Jaseo and Seohong, showed higher ABTS radical scavenging activities than the general white potato extract. Hongyoung and Jayoung had the highest ABTS and DPPH radical scavenging activities. Optical density values for the reducing power of Jayoung and Jaseo at concentration of 2 mg/mL were 0.148 and 0.090, respectively. All colored potato extracts had lower ferrous metal ion chelating effect than the white potato. A significant (P<0.05) positive correlation was observed between total polyphenol content and total flavonoid content (r=0.919), anthocyanin content (r=0.992), and ABTS radical scavenging activity (r=0.897). Based on these results, this research may be useful in developing the Hongyoung and Jayoung cultivars with high antioxidant activities.

• 한국균학회지
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• 제21권3호
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• pp.165-171
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• 1993

표고버섯 중의 광감응성 mitochondrial ATP synthase는 0.1 mM $Fe^{2+}$ 단독 이온에 의하여 그 활성이 대조구에 비해 102%, 증가되었으며, 반면 $Fe^{3+}$ 및 $Mg^{2+}$ 이온은 효소의 활성을 억제시켰다. 0.5 mM $Mg^{2+}$ 존재하에서 0.1 mM $Fe^{2+}$ 이온에 의한 이 효소의 활성은 32% 증가되었으며 0.5 mM $Mg^{2+}$ 존재하에서 $Fe^{3+}$ 이온효과는 단독 $Fe^{3+}$ 이온의 효과와 유사한 경향으로 효소의 활성을 저해하였다. 0.5 mM $Mg^{2+}$과 0.1 mM, 0.5 mM 및 1.0 mM $Fe^{3+}$ 이온의 공존하에서$Fe^{2+}$ 이온에 의한 효소의 활성은 모두 억제되었으며, 특히 0.5 mM $Mg^{2+}$과 0.1 mM $Fe^{3+}$ 이온의 공존하에서 5.0 mM $Fe^{2+}$ 이온에 의하여 53%의 억제현상을 나타내었다. 따라서 표고버섯 중의 광감응성 mitochondrial ATP synthase의 활성은 $Fe^{2+}$ 이온에 의하여 특이적으로 크게 증가되며, 이 효소에 대한 $Fe^{2+}$ 이온의 활성화 효과가 $Mg^{2+}$ 이온에 의하여 크게 영항을 받지 않으나, $Fe^{3+}$ 이온의 공존하에서는 억제됨을 알았다. 활성화 금속이온인 $Fe^{2+}$ 존재하에서 이 효소의 최적 pH는 7.6이며, 최적 온도는 $63^{\circ}C$이었다. 또한 이 효소는 금속 chelating agent인 EDTA에 의하여 효소의 활성이 상실됨으로써 metalloenzyme의 가능성을 제시하였다.