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Non-heme Iron (non-heme + iron)
Selected AbstractsTotal Heme and Non-heme Iron in Raw and Cooked MeatsJOURNAL OF FOOD SCIENCE, Issue 5 2002G. Lombardi-Boccia ABSTRACT: This study provides data on the total heme and non-heme iron contents in poultry (chicken, turkey), beef, veal, lamb, horse, ostrich, rabbit, and pork meat cuts. The effect of cooking on heme iron content was also studied. Total iron and heme iron contents markedly differed between muscles in poultry. Heme iron in red meats ranged from 72 to 87%. Heme iron in rabbit and pork was 56 and 62% of total iron. Heating decreased heme iron, the severity of the losses depended on cooking methods: in poultry, losses ranged from 22 to 43%; less severe impact was detected in pan-cooked meat, where the losses ranged from 1 to 24%. [source] Iron chelation prevents lung injury after major hepatectomyHEPATOLOGY RESEARCH, Issue 8 2010Konstantinos Kalimeris Aim:, Oxidative stress has been implicated in lung injury following ischemia/reperfusion and resection of the liver. We tested whether alleviating oxidative stress with iron chelation could improve lung injury after extended hepatectomy. Methods:, Twelve adult female pigs subjected to liver ischemia for 150 min, 65,70% hepatectomy and reperfusion of the remnant liver for 24 h were randomized to a desferrioxamine (DF) group (n = 6) which received i.v. desferrioxamine to a total dose of 100 mg/kg during both ischemia and reperfusion, and a control (C) group (n = 6). We recorded hemodynamic and respiratory parameters, plasma interleukin-6 and malondialdehyde levels, as well as liver malondialdehyde and protein carbonyls content. Total non-heme iron was measured in lung and liver. Pulmonary tissue was evaluated histologically for its nitrotyrosine and protein carbonyls content and for superoxide dismutase (SOD) and platelet-activating factor acetylhydrolase (PAF-AcH) activities. Results:, Reperfusion of the remnant liver resulted in gradual deterioration of gas-exchange and pulmonary vascular abnormalities. Iron chelation significantly decreased the oxidative markers in plasma, liver and the lung and lowered activities of pulmonary SOD and PAF-AcH. The improved liver function was followed by improved arterial oxygenation and pulmonary vascular resistance. DF also improved alveolar collapse and inflammatory cell infiltration, while serum interleukin-6 increased. Conclusion:, In an experimental pig model that combines liver resection with prolonged ischemia, iron chelation during reperfusion of the remnant liver is associated with improvement of several parameters of oxidative stress, lung injury and arterial oxygenation. [source] Iron(II) Complexes with Bio-Inspired N,N,O Ligands as Oxidation Catalysts: Olefin Epoxidation and cis -DihydroxylationCHEMISTRY - A EUROPEAN JOURNAL, Issue 4 2008Pieter Abstract The Rieske dioxygenases are a group of non-heme iron enzymes, which catalyze the stereospecific cis -dihydroxylation of its substrates. Herein, we report the iron(II) coordination chemistry of the ligands 3,3-bis(1-methylimidazol-2-yl)propionate (L1) and its neutral propyl ester analogue propyl 3,3-bis(1-methylimidazol-2-yl)propionate (PrL1). The molecular structures of two iron(II) complexes with PrL1 were determined and two different coordination modes of the ligand were observed. In [FeII(PrL1)2](BPh4)2 (3) the ligand is facially coordinated to the metal with an N,N,O donor set, whereas in [FeII(PrL1)2(MeOH)2](OTf)2 (4) a bidentate N,N binding mode is found. In 4, the solvent molecules are in a cis arrangement with respect to each other. Complex 4 is a close structural mimic of the crystallographically characterized non-heme iron(II) enzyme apocarotenoid-15,15,-oxygenase (APO). The mechanistic features of APO are thought to be similar to those of the Rieske oxygenases, the original inspiration for this work. The non-heme iron complexes [FeII(PrL1)2](OTf)2 (2) and [FeII(PrL1)2](BPh4)2 (3) were tested in olefin oxidation reactions with H2O2 as the terminal oxidant. Whereas 2 was an active catalyst and both epoxide and cis -dihydroxylation products were observed, 3 showed negligible activity under the same conditions, illustrating the importance of the anion in the reaction. [source] Ethylene Biosynthesis by 1-Aminocyclopropane-1-Carboxylic Acid Oxidase: A DFT StudyCHEMISTRY - A EUROPEAN JOURNAL, Issue 34 2006Arianna Bassan Dr. Abstract The reaction catalyzed by the plant enzyme 1-aminocyclopropane-1-carboxylic acid oxidase (ACCO) was investigated by using hybrid density functional theory. ACCO belongs to the non-heme iron(II) enzyme superfamily and carries out the bicarbonate-dependent two-electron oxidation of its substrate ACC (1-aminocyclopropane-1-carboxylic acid) concomitant with the reduction of dioxygen and oxidation of a reducing agent probably ascorbate. The reaction gives ethylene, CO2, cyanide and two water molecules. A model including the mononuclear iron complex with ACC in the first coordination sphere was used to study the details of OO bond cleavage and cyclopropane ring opening. Calculations imply that this unusual and complex reaction is triggered by a hydrogen atom abstraction step generating a radical on the amino nitrogen of ACC. Subsequently, cyclopropane ring opening followed by OO bond heterolysis leads to a very reactive iron(IV),oxo intermediate, which decomposes to ethylene and cyanoformate with very low energy barriers. The reaction is assisted by bicarbonate located in the second coordination sphere of the metal. [source] | ||||||||||