• Korean Journal of Food Science and Technology
• /
• v.29 no.5
• /
• pp.1052-1056
• /
• 1997

When casein was hydrolyzed by trypsin, alcalase, neutrase, protamax, and S. aureus type V8, peptides $(100\;{\mu}g/mL)$ which were produced by trypsin and alcalase solubilized $6.42\;and\;2.37\;{\mu}g/mL)$ of added irons at pH 6, respectively, while peptides which were produced by other proteases solubilized less than $1\;{\mu}g/mL$. Peptides produced by trypsin and alcalase were fractionated to 10 fractions on a reverse phase column and each fraction was tested for its iron solubilizing ability at pH 6. Among peptides produced by trypsin, fraction 5 showed the highest iron solubilizing ability $(2.33\;{\mu}g/mL)$. In the case of alcalase, fraction 7 showed the highest iron solubilizing ability $(1.56\;{\mu}g/mL)$. To isolate iron binding peptides from peptides produced by trypsin and alcalase, immobilized iron affinity chromatography which irons were chelated to imino diacetic acids in chelating sepharose fast flow were utilized. Our results showed that immobilized iron affinity chromatography was an effective method to isolate iron binding peptides produced by either trypsin or alcalase from milk casein.

• Bulletin of the Korean Chemical Society
• /
• v.23 no.1
• /
• pp.119-122
• /
• 2002

Weakly coordinating anions show little affinity for binding to unfunctionalized iron(II) porphyrins. The electron-deficient 5, 10, 15, 20-tetrakis(pentafluorophenyl)porphinatoiron(II) compound is utilized in this study to demonstrate solution coordination by chloride, bromide and acetate ions. The binding strength of anions to the iron(II) porphyrin is reflected by a systematic change in pyrrole proton chemical shift in $^1H$ NMR spectra; the pyrrole resonance moves downfield when the ${\sigma}$-donor ability of anions is decreased.

• Asian-Australasian Journal of Animal Sciences
• /
• v.26 no.11
• /
• pp.1622-1629
• /
• 2013

The objective of this study was to develop a new method to separate phosvitin from egg yolk without using organic solvents. Phosvitin was extracted from yolk granules using 10% NaCl or 10% $(NH_4)_2SO_4$ (final concentration) and then treated with heat to precipitate the lipoproteins from the extracted solution. The optimal pH for the phosvitin extraction from yolk granules was determined, and the iron-binding ability of the extracted phosvitin (final product) was tested. Adding 10% $(NH_4)_2SO_4$ disrupted the granules, and the subsequent thermal treatment at $90^{\circ}C$ for 1 h precipitated low density and high density lipoproteins, which enabled separation of phosvitin by centrifugation. The phosvitin concentration in the extract was significantly higher when the pH of the solution was adjusted to pH ${\geq}9$. The purity and recovery rate of phosvitin at the end of the separation process were approximately 78% and 56%, respectively. The separated phosvitin was confirmed to have ferrous and ferric iron binding ability. The advantages of this new method compared with the traditional methods include no organic solvents and high-priced equipment are needed for the separation. Also, this method is more environment and consumer friendly than that of the traditional methods.

• Journal of Microbiology
• /
• v.43 no.2
• /
• pp.183-190
• /
• 2005

Staphylococcus aureus is known to be capable of utilizing transferrin-bound iron, via both siderophore­and transferrin-binding protein (named IsdA)-mediated iron-acquisition systems. This study was designed in order to determine which iron-acquisition system plays the essential or dominant role with respect to the acquisition of iron from human transfenin, in the growth of S. aureus. Holotransferrin (HT) and partially iron-saturated transferrin (PT), but not apotransferrin (AT), were found to stimulate the growth of S. aureus. S. aureus consumed most of the transferrin-bound iron during the exponential growth phase. Extracellular proteases were not, however, involved in the liberation of iron from transferrin. Transferrin-binding to the washed whole cells via IsdA was not observed during the culture. The expression of IsdA was observed only in the deferrated media with AT, but not in the media supplemented with PT or HT. In contrast, siderophores were definitely produced in the deferrated media with PT and HT, as well as in the media supplemented with AT. The siderophores proved to have the ability to remove iron directly from transferrin, but the washed whole cells expressing IsdA did not. In the bioassay, the growth of S. aureus on transferrin-bound iron was stimulated by the siderophores alone. These results demonstrate that the siderophore-mediated iron-acquisition system plays a dominant and essential role in the uptake of iron from transferrin, whereas the IsdA-mediated iron-acquisition system may play only an ancillary role in the uptake of iron from transferrin.

• Food Science of Animal Resources
• /
• v.22 no.1
• /
• pp.13-19
• /
• 2002

The natural sources extracted from green tea and pine needle were utilized to investigate the effects of extracts on free radical reaction, lipid oxidation and nitrite scavenging ability. The degree of lipid oxidation is very sensitive to kinds of oil emulsion reacted with iron sources and oxygen species. The antioxidants of extracts from green tea and pine needle were different depending on concentration of extracts, which were a lower TBARS value in 0.3% extracts concentration, compared to 0.1% extracts concentration. And also, the binding ability on iron sources was superior in hot water extracts, but oxygen scavenging ability was the lowest TBARS values in ethanol extracts. The hydroxyl radical scavenging ability of green tea and pine needle extracts had a little low TBARS value in 0.1% and 0.3% extracts concentration in deoxyribose. The ethanol extracts of pine needle were higher than those of hot water extracts on the basis of Fe$\_$2+/ ion content. The ascorbic acid content of green tea showed 14.3 mg/100g in hot water extracts and 16.7 mg/100 g in ethanol extracts. Electron donating ability of extracts showed difference depending on extracts concentration, which were higher in ethanol extracts than those of hot water extracts. The nitrite scavenging effects were tended to be different depending on pH value, however they were decreased overall as pH value was increased. Especially, the nitrite scavenging ability of 0.3% extracts from green tea and pine needle were the mosts effective in pH 1.2 and pH 3.0, which were showed 95% nitrite scavenging ability.

• Archives of Pharmacal Research
• /
• v.29 no.3
• /
• pp.249-255
• /
• 2006

Ability of iron acquisition of pathogenic microorganisms functions as a virulence factor. Candida albicans, a fungal pathogen that requires iron for growth, is susceptible to growth retardation by high-affinity iron binding proteins such as transferrin. Recently, we reported that C. albicans could utilize the heme as a part of heme-containing proteins dissociated by heme oxygenase, CaHMX1. In search of another pathway that C. albicans can use to bypass the growth regulation produced by iron limitation, this present study examined utilization of non-candidal siderophores such as Desferal and rhodotorulic acid (RA) for acquisition of inorganic iron by the fungus. C. albicans secreting no siderophores was cultured in iron-free (pretreated with apotransferrin for 24 h) (culture medium). Once growth of the yeast reached stasis from iron starvation, a siderophore was added to the culture media. Results showed that cultures containing apotransferrin within a dialysis membrane recovered growth to the level of untreated controls, whereas C. albicans yeast cells in direct contact with soluble iron-free (apo) transferrin recovered growth only partially. When static growth from iron limitation was reached, the addition of siderophore-apotransferrin complex to culture medium also permitted the yeast to recover growth from apotransferrin growth regulation. All the data show that C. albicans can utilize the non-candidal siderophores for iron acquisition under transferrin regulation as can pathogenic bacteria.

• Food Science and Preservation
• /
• v.6 no.1
• /
• pp.115-120
• /
• 1999

This study was carried out to investigate the effect of Pine needle extract on lipid oxidation and free radical reaction in iron sources reacted with active oxygen species. The results were summarized as follow; The pine needle extracts didn`t show a distinct effect on reduction of lipid oxidation if the iron ion didn`t exist in oil emulsion. The pine needle extracts played role as a strong chelating agents to bind iron ion if Ferrous iron(Fe\ulcorner) exist in oil emulsion. Ferric iron(Fe) was lower effect than Ferrous iron(Fe) on free radical reaction in oil emulsion. And also, the Fe\ulcorner reacted with pine needle extract did not show distinct effect on free radical reaction, compared to Fe\ulcorner reacted with pine needle extract. And also, Pine needle extracts reacted with H\ulcornerO\ulcorner were tended to show a low oxygen scavenging ability in case of H\ulcornerO\ulcorner only was existed, compared to those of H\ulcornerO\ulcorner + Fe\ulcorner complex. Pine needle extracts were the most powerful Fe\ulcorner binding agents, compared to other strong synthetic antioxidants such as EDTA and DTPA.

• Korean Journal of Food Science and Technology
• /
• v.31 no.2
• /
• pp.527-534
• /
• 1999

This study was carried out to investigate the effects of pine needle extracts on lipid oxidation and free radical reaction in iron sources reacted with active oxygen species. The results were summarized as follow; the catalytic effects of active oxygen on lipid oxidation in oil emulsion tended to be showed $OH,\;H_2O_2\;and\;KO_2$ in order. At the same time, pine needle extracts itself were tended to be showed a little catalytic effects. Active oxygen scavenging ability of pine needle extracts didn't show, but pine needle extracts played role as a strong chelating agents to bind iron ion if $Fe^{2+}$ ion exist in oil emulsion. The content of $Fe^{2+}$ ion and total iron in CPNP were higher than those of HPNP and FPN. The content of ascorbic acid of FPN showed the highest (87.77 ppm) among several pine needle extracts. Electron donating ability of HPNP and CPNP were 81% and 78%, respectively, which were showed higher content than those of FPN. The SOD-like activity of HPNP showed 44.30%, compared to other pine needle extracts which means the most strong antioxidant reaction. The nitrite scavenging effects were tended to be different, depending on pH value as pH value was increased. Especially, they didn't show the nitrite scavenging effect in pH6.0.

• Food Science of Animal Resources
• /
• v.32 no.2
• /
• pp.162-167
• /
• 2012

Phosvitin was extracted from a chicken egg yolk and the iron-binding, along with antioxidative activity of the extracted phosvitin, was determined after mixing with ground beef at the concentrations of 100 and 500 mg/kg of meat. The electrophoretic pattern of the extracted phosvitin on SDS-PAGE was found to be identical to that of the standard phosvitin. The extracted phosvitin at $1,000{\mu}g$/mL showed an ability to bind approximately 65% of the iron in a 3 mM iron solution. Lipid oxidation was inhibited in the ground beef mixed with 500 mg/kg of the extracted phosvitin, during storage at $4^{\circ}C$ compared to that of the control (p<0.05). Additionally, color stability of ground beef containing the extracted phosvitin was enhanced (p<0.05). The pH, cooking loss, texture, and sensory properties of the ground beef were not affected, by adding up to 500 mg/kg of the extracted phosvitin. This result suggests that the phosvitin extracted from egg yolk could be used as an antioxidant reagent. In particular, phosvitin would be more amenable for use in meat products because it is a natural protein derived from animal products.

• Preventive Nutrition and Food Science
• /
• v.8 no.1
• /
• pp.70-74
• /
• 2003

This study investigated the relationship of Helicobacter pylori (H. pylori) infection to iron-deficiency anemia in high school girls. Four hundred and fourty-five subjects resided in Ulsan City in Korea were evaluated by questionnaire or blood analysis for serum indicators of iron status, daily nutrient intakes, symptoms of anemia, and H. pylori IgG antibody status. In H. pylori infected subjects, total energy intake of was 1534.14±350.81 kcal (73.0% of the Korean RDA), the iron intake of subjects was 11.38±3.90 mg (71.1% of Korean RDA) and calcium intake was 467.63±175.96 mg (58.3% of the Korean RDA). Carbohydrate (p < 0.05), vitamin A (p < 0.05), vitamin C (p < 0.01) intakes were significantly lower in infected subjects than in non-infected subjects. The prevalence of anemia (hemoglobin (Hb) < 12 g/dL.) in H. pylori infected subjects was 22.7% as compared to 14.7% in non-infected subjects. The mean serum ferritin of infected subjects (21.71±21.50 ng/mL) was significantly lower than in non-infected subjects (p < 0.05) (as was the mean Hb concentration (12.54±1.51 g/dL) and hematocrit (37.99±3.64%)). Total iron binding capacity (TIBC) of H. pylori infected subjects (449.09±78.23 ㎍/dL) was significantly higher than that of non-infected subjects (432.99＋76.15 ㎍/dL) (P < 0.05). The levels of iron, red blood cell (RBC) and transferrin saturation were similar in infected and non-infected subjects. Two symptoms of anemia, 'pale face (p < 0.01)' and 'decreased ability to concentrate (p < 0.005)', were significantly higher in H. pylori infected subjects than in non-infected subjects. High school girls are known to be more vulnerable to iron deficiency than other age groups, and this research demonstrates that infection with H. pylori increases their risk of iron-deficiency anemia.