Amyloid b-peptide (Ab), the central constituent of senile plaques in Alzheimer’s disease (AD) brain, has been shown to be a source of free radical oxidative stress that may lead to neurodegeneration. In the current study Ab(1-40), found in AD brain, and the amyloid fragment Ab(25-35) were used in conjunction with electron paramagnetic resonance spin trapping techniques to demonstrate that these...

Phagocytes secrete the heme protein myeloperoxidase, which is present and active in human atherosclerotic tissue. These cells also generate hydrogen peroxide (H2O2), thereby allowing myeloperoxidase to generate a range of oxidizing intermediates and stable end products. When this system acts on L-tyrosine in vitro, it forms o, o'-dityrosine, which is enriched in atherosclerotic lesions. Myelope...

Using the spin trap a-(4-pyridyl-l-oxide)-A'-fert-butylnitrone, we have detected a lipid-derived carbon-centered free radical generated from in tact 1,1210 lymphoblastic leukemia cells that were exposed to 1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphocholine (edelfosine or I IIK-()( II,) and oxidative stress. The spectral characteristics, including hyperfine splitting constants of ¡IN= 15.61G...

Using the spin trap alpha-(4-pyridyl-1-oxide)-N-tert-butylnitrone, we have detected a lipid-derived carbon-centered free radical generated from intact L1210 lymphoblastic leukemia cells that were exposed to 1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphocholine (edelfosine or ET-18-OCH3) and oxidative stress. The spectral characteristics, including hyperfine splitting constants of aN = 15.61G an...

The peroxidaee action of myoglobin and haemoglobin has been recognised for several decades [l]. The interaction of MetMb with peroxides involves the formation of a ferry1 (iron IV-0x0) species and a protein radical [2]. It is not clear which of these species is responsible €or oxidative damage to biological substrates. It has been proposed that the radical on the surface of the haem protein is ...

Electron impact (EI) tandem mass spectrometry (MS/MS) combined with EPR spin trapping was used to detect and identify the free radical metabolites of various halocarbons in rat liver microsomal dispersions. EPR spectra of the spin adducts of radical metabolites derived from fluorine-containing halocarbons display fluorine hyperfine splitting, which can be used as proof for the identification of...

An iron-catalyzed diboration reaction of alkynes with bis(pinacolato)diboron (B2pin2) and external borating agents (MeOB(OR)2) affords diverse symmetrical or unsymmetrical cis-1,2-diborylalkenes. The simple protocol for the diboration reaction can be extended to the iron-catalyzed carboboration of alkynes with primary and, unprecedentedly, secondary alkyl halides, affording various tetrasubstit...