• Textile Coloration and Finishing
• /
• v.18 no.1
• /
• pp.10-19
• /
• 2006

Despite several recent attempts to measure the concentration of individual catechins by HPLC, it has not been so easy to separate catechins accurately. The aim of the present work is to provide a proper condition for separating each component of catechins by HPLC analysis, and also to evaluate the experimental variables including color differences, and metal ion contents after dyeing and mordanting. Four kinds of Catechins, (-)-epicatechin(EC), (-)-epicatechin gallate(ECG), (-)-epigallocatechin(EgC), (-)-epigallocatechin gllate(EgCG) were isolated from the residues after dyeing. Catechins in Korean green tea leaves are richer when e tea leaves are younger. Higher concentration of catechins owes it to e way it is processed. The contents of catechins adsorbed in silk fabrics after dyeing were in order of EGCG>ECG>EGC>EC. We have found $68\%$ uptake of EGCG, and 116.8mg of EGCG in the silk fabrics after it was dyed with $1\%$ Korean green tea extracts. The absorbance intensity and K/S values of dyed silk fabrics were increased with dyeing temperature and time. Only the surface color of the silk fabric dyed with green tea extracts was yellowish red, but it changed from yellowish red to red with an increase in the mordant concentration. Post-mordanted silk fabrics with ferrous sulfate changed from yellowish red to red and purple color shade. In a practical evaluation, there is no significant change in color after twenty times of the continuous dry cleaning process. However, post-mordanted fabrics with ferrous sulfate faded the brightness of color after dry cleaning. Dyeing silk fabrics with a Korean tea extract reduced the metal ion contents in the silk fabrics when compared to the untreated silk fabrics. Metal contents in silk fabrics dyed and post-mordanted with $1\%$ each metal solution were 0.194 ppm for Aluminum, 1.601ppm for Copper, and 0.334 ppm for Iron. After the post-mordanting process, the heavy metal ion absorption increased, which was mainly attributed to the catechins and polyphenols in dyed silk fabrics.

• 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.

• Journal of the East Asian Society of Dietary Life
• /
• v.22 no.5
• /
• pp.657-666
• /
• 2012

The purpose of this study was to improve the quality of Korean traditional sauce products by producing short-term green gochujang with cheongyang pepper powder. To determine its antioxidant compounds and activities, we examined vitamin C, capsaicinoid, total phenolic, and total flavonoid contents, as well as electron-donating, SOD-like, ferrous ion-chelating, and nitrite-scavenging activities. Vitamin C content of short-term green gochujang was higher in CON-M than in the sample, whereas capsaicinoid content increased as the amount of cheongyang pepper powder increased. Total phenolic content, total flavonoid content, electron-donating activity, and nitrite-scavenging activity were higher in the sample than in CON-M, and the contents increased as the amount of meju powder increased. Green gochujang containing the highest amount of cheongyang pepper powder showed the highest SOD-like, and ferrous-ion chelating activities as well as superior nutrient contents, compared to red gochujang.

• Journal of the Korean Applied Science and Technology
• /
• v.33 no.2
• /
• pp.342-351
• /
• 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.

• Archives of Pharmacal Research
• /
• v.15 no.4
• /
• pp.309-316
• /
• 1992

The effects of lipid peroxidation on the fluidity of the lipid bilayers of the human erythrocyte ghosts and egg-lecithin phospholipid liposomes have been studied. For the measurements of the peroxidation extent and the fluidity of the membranes, the thiobarbituric acid-reactive substances and the fluorescence depolarization of 1, 6-diphynyl-1, 3, 5-hexatriene labelled into the membrane were employed, respectively. The lipid peroxidation was performed in hypoxanthine/xanthine oxidase/ferrous ion, and hydrogen peroxide/ferrous ion systems. The results of these experiments show that both of the xanthine oxidase and hydrogen peroxide systems effectively. The lipid peroxidation decreased the fluidity of the membranes, especially at the very early stage of the peroxidation reaction. The decrease in the fluidity of membrane by the lipid peroxidation has been ascribed to the alteration of the polyunsaturated acyl chains of lipids and cross linkages among the membrane components. However, under drastic condition of lipid peroxidation, tdhe fluidity of the membrane rather increased possibly due to the deterioration of the membrane integrity by the peroxidation. Morphological change of the erythrocyte on peroxidation has also been observed.

• Journal of Soil and Groundwater Environment
• /
• v.13 no.1
• /
• pp.24-31
• /
• 2008

Sulfate reducing bacteria (SRB) is universally distributed in the sediment, especially in marine environment. SRB reduce sulfate as electron acceptor to hydrogen sulfide in anaerobic condition. Hydrogen sulfide is reducing agent enhancing the reduction of the organic and inorganic compounds. With SRB, therefore, the degradability of organic contaminants is expected to be enhanced. Ferrous iron reduced from the ferric iron which is mainly present in sediment also renders chlorinated organic compounds to be reduced state. The objectives of this study are: 1) to investigate the reduction of TCE by hydrogen sulfide generated by tht growth of SRB, 2) to estimate the reduction of TCE by ferrous iron generated due to oxidation of hydrogen sulfide, and 3) to illuminate the interaction between SRB and ferrous iron. Mixed bacteria was cultivated from the sludge of the sewage treatment plant. Increasing hydrogen sulfide and decreasing sulfate confirmed the existence of SRB in mixed culture. Although hydrogen sulfide lonely could reduce TCE, the concentration of hydrogen sulfide produced by SRB was not sufficient to reduce TCE directly. With hematite as ferric iron, hydrogen sulfide produced by SRB was consumed to reduce ferric ion to ferrous ion and ferrous iron produced by hydrogen sulfide oxidation decreased the concentration of TCE. Tests with seawater confirmed that the activity of SRB was dependent on the carbon source concentration.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.1B
• /
• pp.149-152
• /
• 2008

The reaction between iron oxide and ferrous iron is known to be the adsorption of ferrous iron onto the oxide surfaces that produces Fe(II)-Fe(III) (hydr)oxides and ferrous oxide oxidized to ferric ion which is the reducing agent of the target compounds. In our investigations on DS/S using ferrous modified steel slag, the results did not follow the trends. FeO and Fe(II), the major component of steel slag, were used to investigate the degradation of TCE. Degradation did not take place for the first and suddenly degraded after awhile. Degradation of TCE in this system was unexpected because Fe(II)-Fe(III) (hydr)oxides could not be produced in absence of ferric oxide. In this study, the characteristics of FeO/Fe(II) system as a reducing agent were observed through the degradation of TCE, measuring byproducts of TCE and the concentration of Fe(II) and Fe(III). Adsorption of ferrous ion on FeO was observed and the generation of byproducts of TCE showed the degradation of TCE by reduction in the system is obvious. However it did not correspond with the typical reducing mechanisms. Future research on this system needs to be continued to find out whether new species are generated or any unknown mineral oxides are produced in the system that acted in the degradation of TCE.

• Corrosion Science and Technology
• /
• v.5 no.2
• /
• pp.39-44
• /
• 2006

The dissolution amount of Zn plate was $0.058mg/cm^2$ in the non-magnetically treated solution, and was $0.059mg/cm^2$ in the magnetically treated solution after 24 hours of immersion. The magnetic treatment had no effect to corrosion of Zn plate as pH on surface was not recognized the difference. The addition of Zn(II) ion in the solution was prepared to the effects of corrosion and dissolution of Fe. The regularity was not obtained the effect of the magnetic treatment on the dissolution of Fe plate.

• Bulletin of the Korean Chemical Society
• /
• v.18 no.6
• /
• pp.644-648
• /
• 1997

Introduction of an alkyl substituent at the $C_{4\beta}$ position of antimalarial trioxanes has caused them to become more active in their antimalarial activity. We have designed a structurally simple 4β-phenyl substituted trioxane (3) as an active antimalarial since it can form a more stable carbon radical when reacting with ferrous bromide. The trioxane 3 has been prepared along with the corresponding isomer 4 according to the previously reported procedure. The synthesized trioxanes 3 and 4 were finally separated by using HPLC and assigned their stereochemistry by spectroscopy and X-ray crystallography. Their antimalarial activities were surprisingly low. The low activity was then rationalized based on the product distribution of the ferrous ion induced reaction of these trioxanes. These trioxanes with ferrous bromide did not produce any detectable amount of the corresponding $C_4$-hydroxylated product, consistent with the fact that neither $C_{4\beta}$-phenyl substituted nor $C_{4\alpha}$-phenyl substituted trioxane has any antimalarial activity. It implies that a $C_4$ substituent of antimalarial trioxanes has to stabilize an adjacent carbon-centered radical in a specific stability range in order to show a good antimalarial activity. This study, combined with related studies, could help develop more potent antimalarial trioxanes.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
• /
• 2004.10a
• /
• pp.270-273
• /
• 2004

Lactobacillus spp.의 항산화 효과를 측정한 결과 L. bulgaricus LB 207의 cell lysate와 intact cell 모두에서 항산화 효과가 높게 측정되었다. 또한 이들 균주들은 높은 ferrous iron 흡착능을 나타내었으나 항산화 효과 사이의 연관성을 설명하기는 어려웠다. 유산균의항산화 메커니즘과 in vivo 실험을 통한 더욱 구체적인 항산화 효과에 대한 연구가 필요 하며, 다양한 항산화 메커니즘을 통하여 항산화 유산균 인간의 활성산소 축적의 위험으로부터 보호해 줄 수 있을 것으로 생각된다.