• Restorative Dentistry and Endodontics
• /
• v.34 no.6
• /
• pp.484-490
• /
• 2009

The purpose of this study was to evaluate the effect of soft chelating irrigant on the sealing ability of root fillings by using a glucose leakage test. A total of 45 single-rooted teeth were selected for the study. The teeth were decoronated leaving a total length of 13mm. The root canals prepared using K3 NiTi rotary instruments to an apical dimension of size 45(0.06 taper). The specimens were then randomly divided into 3 experimental groups of 13 roots each and 2 control groups of 3 roots each. Specimen in each group were prepared with different irrigation protocols : group 1, 2.5% NaOCl; group 2, 2.5% NaOCl and 17% EDTA: group 3, 2.5% NaOCl and 15% HEBP. The root canals were filled with gutta-percha and AH Plus sealer using lateral condensation. After 7 days in $37^{\circ}C$, 100% humidity, the coronal-to-apical microleakage was evaluated quantitatively using a glucose leakage model. The leaked glucose concentration was measured with spectrophotometry at 1, 4, 7, 14, 21 and 28 days. There was a tendency of increase in leakage in all experimental groups during experimental period. HEBP-treated dentin showed no significant difference with EDTA-treated dentin during experimental period. From the 21th day onward, HEBP-treated dentin showed significantly lower leakage than smear-covered dentin. HEBP-treated dentin displayed a similar sealing pattern to EDTA-treated dentin and a better sealing ability than smear-covered dentin. Consequently, a soft chelator(HEBP) could be considered as the possible alternative to EDTA.

• Food Science and Preservation
• /
• v.18 no.1
• /
• pp.59-64
• /
• 2011

This study was performed to investigate antioxidant activity of various solvent extracts (methanol, ethanol, acetone and water) from canola meal. As the concentration of all extracts increased, antioxidant activities increased gradually. Among solvent extracts from canola meal, methanol extract showed the highest antioxidant activities with $EC_{50}$ values of 0.9, 3.5, 1.3, and 8.5 mg/mL for DPPH radical scavenging ability, ABTS radical scavenging ability, reducing power, and chelating ability, respectively, and it had the highest total phenolics and total flavonoids contents. Furthermore, methanol extract was fractionated into three fractions (MF 1, MF 2, and MF 3) using Sephadex LH-20 column. The highest antioxidant activity was found on MF 2 for DPPH radical scavenging ability, on MF 3 for ABTS radical scavenging ability and reducing power, and on MF 1 for chelating ability at the same concentration of 1.5 mg/mL. The results indicated that each fraction containing various antioxidant materials seemed to have different influence at each antioxidant activity.

• Preventive Nutrition and Food Science
• /
• v.14 no.4
• /
• pp.277-282
• /
• 2009

The antioxidant potency of methanolic extract of Duchesnea indica (MDI; Indian strawberry) was investigated by employing various established in vitro systems, such as total phenolic content, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity, reducing power assay, metal chelating assay, superoxide radical scavenging activity and protective ability of DNA damage and protein oxidation. MDI inhibited metal chelating by 75.57% at 2 mg/mL, scavenged 50% DPPH free radical at 29.13 ${\mu}$g/mL, and eliminated approximately 46.21% superoxide radical at the concentration of 1 mg/mL. In addition, MDI showed strong ability on reducing power, DNA damage protection and protein oxidation protection. Overall, results suggested that MDI might be beneficial as a potent antioxidant and effectively employed as an ingredient in food applications.

• Journal of Applied Biological Chemistry
• /
• v.54 no.1
• /
• pp.33-40
• /
• 2011

Ionizing radiation can be used to improve the color of green tea extract to brighter. As a result, the irradiated green tea extract can be applied easier and broader in food or cosmetic industry. To confirm the retention of the biological activities of the cosmetic products added with green tea polyphenols (PPs), the real cosmetic products including a skin lotion (PS) and an essence (PE) cream were manufactured. Irradiation also applied to the manufactured cosmetic products to see their improvement of color and changes of biological activity. The PP showed 72% of electron donating ability (EDA) at a 5 ppm concentration and the PS and PE containing 2% PP showed higher than 60%, which was similar inhibition activity to vitamin C. The inhibition of superoxide dismutase (SOD)-like activity of PP, PS, and PE were higher than 55% at a 500 ppm concentration and the inhibition of xanthine oxidase (XOase) were also higher than 65% at a 200 ppm concentration. The measurement of lipid oxidation by addition of $Cu^{2+}$ and $Fe^{2+}$ as prooxidants showed that PP and PS had higher metal chelating ability for $Fe^{2+}$ than that of PE and the ability increased by increase of polyphenol concentration isolated from green tea. The $Cu^{2+}$ chelating ability of PP and PS showed higher than 90% at a 200 ppm concentration. Therefore, it is concluded that addition of PP in manufacturing PS and PE retains its biological activities including EDA, inhibition of XOase and SOD-like activity, and metal chelating ability in the manufactured cosmetic products. In addition, irradiation of PS and PE improved color of the products containing PP brighter without any adverse changes in biological activity of the products.

• Bulletin of the Korean Chemical Society
• /
• v.29 no.7
• /
• pp.1327-1331
• /
• 2008

Novel $CO_2$-soluble 8-hydroxyquinoline (8-HQ) chelating agents were synthesized and evaluated for solubility and metal ion extraction ability in supercritical $CO_2\;(Sc-CO_2)$. Among them, secondary amide-containing 8- HQ derivatives cannot be dispersed well into Sc-$CO_2$, but tertiary amide-containing derivatives can dissolve completely in Sc-$CO_2$ even at low CO2 pressures, perhaps owing to the predominant intermolecular interaction between the chelating agent and the $CO_2$ molecule. Based on 8-HQ chelating agent solubility data, we investigated the extraction of metal ions ($Co^{2+}$, $Cu^{2+}$, $Sr^{2+}$, $Cd^{2+}$, and $Zn^{2+}$) using two highly $CO_2$-soluble 8-HQ derivatives (4d, 4e) in Sc-$CO_2$. The extraction efficiency of tertiary amide-containing 8-HQ ligands, both fluorinated and non-fluorinated forms, was dramatically increased in the presence of diethyl amine (organic base). We suggest that diethyl amine could play an important synergistic role in the stronger metal binding ability of 8-HQ through an in situ deprotonation reaction in Sc-$CO_2$ medium.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.31 no.6
• /
• pp.1097-1101
• /
• 2002

This study was conducted to investigate the efficacy of antioxidant ability and nitrite scavenging ability of Poria cocos Poria cocos mycelium and Poria cocos fermented with rice were extracted with water and ethanol for measurement of degree of fat acidification against fish oil. Lower TBARS values of Poria cocos mycelium and Poria cocos fermented with rice were shown compared with control. Iron chelating ability of Poria cocos mycelium against Fe$^{2+}$, Cu$^{2+}$ was higher than Poria cocos fermented with rice. Electron donating abilitv of water extract and ethanol extract of Poria cocos mycelium were 76.8% and 79.9%, respectively. Higher nitrite scavenging ability was shown at ethanol extract than water extract of Poria cocos mycelium.ium.

• Asian-Australasian Journal of Animal Sciences
• /
• v.18 no.4
• /
• pp.567-573
• /
• 2005

This study aims to evaluate the antioxidative activities of cow-milk kefir and goat-milk kefir. Antioxidative mechanisms, including radical-scavenging effects, ferrous-ion chelating ability, reducing power and antioxidant activity, were investigated herein. Kefirs demonstrated significantly greater scavenging effects upon 1,1-diphenyl-2-picrylhydrazyl (DPPH) and superoxide radicals, an inhibition effect upon linoleic-acid peroxidation, and more substantial reducing power, but reduced glutathione peroxidase (GSH-Px) activity than was the case for milks. There was no significant difference between milks and kefirs as regards ferrous-ion chelating ability and superoxide dismutase (SOD) activity. These findings have demonstrated that kefirs possess antioxidant activity, thereby suggesting that kefirs are potential candidates for the role of useful natural antioxidant supplements for the human diet.

• Bulletin of the Korean Chemical Society
• /
• v.35 no.4
• /
• pp.1087-1090
• /
• 2014

A simple and general method that selectively introduces metal binding sites into a protein can greatly increase the ability to design and biosynthesize artificial metalloproteins. Here, we report the incorporation of a phenanthroline-containing amino acid (Phen-Ala) into proteins in Escherichia coli by using the $tRNA{^{Tyr}}_{CUA}$ and tyrosyl aminoacyl-tRNA synthetase pair (BpyRS) from Methanococcus jannaschii, which was originally developed for a bipyridine-containing amino acid (Bpy-Ala). The incorporation efficiency of BpyRS for Phen-Ala was comparable to that for Bpy-Ala. Because of its high metal-binding ability and characteristic spectral properties, Phen-Ala can be a useful alternative to the existing metal-chelating amino acids for the design and synthesis of artificial metalloproteins.

• The Korean Journal of Food And Nutrition
• /
• v.35 no.5
• /
• pp.313-323
• /
• 2022

To investigate antioxidant effects of tea tree root extracts using various extraction methods, cytotoxicity, DPPH and ABTS radical scavenging, SOD, nitrite scavenging activity and inhibitory activity of lipid peroxidation, reducing power, ferrous ion chelating activity were measured. Cytotoxicity for RAW 264.7 cells was not observed at concentrations treated with below 90 ㎍/mL in all extracts. The maximum DPPH radical, nitrite scavenging, SOD activity and inhibitory activity of lipid peroxidation were obtained at the ethylacetate and 70% ethanol extract. The maximum ABTS radical scavenging activity was obtained at the ethylacetate and hot water extract. However, in the case of reducing power and ferrous ion chelating activity, they were obtained at 70% ethanol and hexane extract, respectively. Nitrate scavenging activity showed the most excellent scavenging ability of 59.6% at 90 ㎍/mL of ethylacetate. The hexane extract had the highest ferrous ion chelating activity, showing 61.05% at 50 ㎍/mL, 66.07% at 70 ㎍/mL and 76.81% at 90 ㎍/mL, respectively. The results of this research show that the ethylacetate and 70% ethanol extracts of tea tree root can be used as a natural material for scavenging the radicals. However, future study is necessary to understand the mechanism of antioxidant activity by identification of substances.

• Journal of the East Asian Society of Dietary Life
• /
• v.24 no.2
• /
• pp.183-189
• /
• 2014

We investigated noodles supplemented with functional ingredients for their antioxidant properties, including total phenol, flavonoid contents, electron donating, nitrite scavenging abilities and ferrous ion chelating effect. The total polyphenol contents of functional noodles arranged in order of decreasing concentration were kudzu (7.98%) > green tea (4.99%) > pumpkin (5.03%) > mulberry leaves (4.99%) > mugwort (4.23%) > cactus (3.57%) > kelp (3.33). The total flavonoid contents in green tea noodles were the highest as 4.35%. The electron donating ability in mugwort noodle was the highest as 12.27% at 1,000 ppm. This amount was 4.85 times than that of wheat flour noodle (2.53%). The nitrite scavenging ability of functional noodles at pH 1.2 arranged in order of decreasing concentration were green tea (66.52%) > cactus (55.12%) > kudzu (52.67%) > pumpkin (50.50%) > mulberry leaves (43.58%) > kelp (41.41%) > mugwort (37.66). The nitrite-scavenging ability of green tea noodle was lower than ascorbic acid (natural antioxidant) 77.83%, while that of green tea noodle was similar with BHT (artificial antioxidant) 69.45%. The ferrous ion chelating effect of noodles containing kelp were the highest as 27.02%. All of the experimental results showed good antioxidant property. Thus, noodles supplemented with mulberry leaves, cactus, mugwort, green tea, pumpkin, kelp or kudzu, demonstrated to have good functional effects for human health.