OBJECTIVES Metals such as iron are needed for physiological functions of the body. However, their excess may cause serious damage including poisoning. The effects of Fe2+ and Fe3+ ions on human plasma cholinesterase activity were investigated. MATERIAL AND METHODS Plasma were obtained (n = 24) from healthy male volunteers, and treated with five various concentrations of Fe2+ and Fe3+ ions. Ac...

When Fe2+ ions are added to rat-liver microsomes, lipid peroxidation begins after a short lag period. Fe2+-dependent peroxidation in the first few minutes of the incubation can be increased by adding Fe3+, ascorbic acid or Pb2+ ions; these stimulations are not additive. By contrast, Pb2+ ions inhibit peroxidation of microsomes in the presence of Fe3+/ascorbate or Fe3+-ADP/NADPH. In liposomes ma...

Oligosilanes with attached silatranyl units were obtained by reactions of potassium oligosilanides with a silatranyl triflate. Interaction between Si and N atoms was observed in the 29Si NMR spectra (upfield-shifted SiO3 resonances) and in the solid-state structures (Si-N distances between 2.29 and 2.16 Å). The Si-N interaction can be "switched off" either by protonation of the nitrogen lone pa...

A dinucleating macrocycle, H2PIM, containing phenoxylimine metal-binding units has been prepared. Reaction of H2PIM with [Fe2(Mes)4] (Mes = 2,4,6-trimethylphenyl) and sterically hindered carboxylic acids, Ph3CCO2H or ArCO2H (2,6-bis(p-tolyl)benzoic acid), afforded complexes [Fe2(PIM)(Ph3CCO2)2] (1) and [Fe2(PIM)(ArCO2)2] (2), respectively. X-ray diffraction studies revealed that these diiron(II...

Studies were carried out to determine the actions of and interactions between ascorbate, NADPH, Fe2+, and Fe3+ on lipid peroxidation in adrenal and testicular microsomes. Ascorbate-induced malonaldehyde production was maximal in adrenal and testicular microsomes at an ascorbate concentration of 1 X 10(-4)M. Fe2+, at levels between 10(-6) and 10(-3)M, produced concentration-dependent increases i...

a graphene oxide-terpyridine conjugate (gotc) based colorimetric and fluorescent nano-chemosensor was synthesized. it showed high selectivity and sensitivity for fe2+ and fe3+ ions in neutral aqueous solution over other metal ions such as li+, na+, ba2+, ca2+, al3+, cd2+, co2+, cu2+, hg2+, mn2+, ni2+, pb2+, zn2+, cr3+ and ag+. in absorption spectra, upon addition of fe2+ or fe3+, the sensor dis...

Deoxyribose test has been widely used for determination of reactivities of various compounds for the hydroxyl radical. The test is based on the formation of hydroxyl radical by Fe2+ complex in the Fenton reaction. We propose a modification of the deoxyribose test to detect strong iron binding, inhibiting participation of Fe2+ in the Fenton reaction, on the basis of examination of concentration ...