Biomaterial Database

Radical anions from one-electron-reduced adrenochrome. Detection and identification by electron spin resonance spectroscopy. 1985

B S Prabhananda, and B Kalyanaraman, and R C Sealy

Free radicals from the one-electron reduction of adrenochrome have been studied in aqueous solutions. These radicals have been detected and identified by electron spin resonance spectroscopy, using spin stabilization methods (complexation with diamagnetic metal ions) to enhance radical concentrations. It is shown that the radicals have a characteristic ESR spectrum enabling their identification in complex systems. The spin density distribution in the radicals has been studied as a function of complexing metal ions and solvent composition. In the presence of oxidants (e.g., oxygen) the spectrum of the radical is replaced by that derived from the one-electron exidation of adrenochrome.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008670	Metals	Electropositive chemical elements characterized by ductility, malleability, luster, and conductance of heat and electricity. They can replace the hydrogen of an acid and form bases with hydroxyl radicals. (Grant & Hackh's Chemical Dictionary, 5th ed)	Metal
D010084	Oxidation-Reduction	A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).	Redox,Oxidation Reduction
D004578	Electron Spin Resonance Spectroscopy	A technique applicable to the wide variety of substances which exhibit paramagnetism because of the magnetic moments of unpaired electrons. The spectra are useful for detection and identification, for determination of electron structure, for study of interactions between molecules, and for measurement of nuclear spins and moments. (From McGraw-Hill Encyclopedia of Science and Technology, 7th edition) Electron nuclear double resonance (ENDOR) spectroscopy is a variant of the technique which can give enhanced resolution. Electron spin resonance analysis can now be used in vivo, including imaging applications such as MAGNETIC RESONANCE IMAGING.	ENDOR,Electron Nuclear Double Resonance,Electron Paramagnetic Resonance,Paramagnetic Resonance,Electron Spin Resonance,Paramagnetic Resonance, Electron,Resonance, Electron Paramagnetic,Resonance, Electron Spin,Resonance, Paramagnetic
D005609	Free Radicals	Highly reactive molecules with an unsatisfied electron valence pair. Free radicals are produced in both normal and pathological processes. Free radicals include reactive oxygen and nitrogen species (RONS). They are proven or suspected agents of tissue damage in a wide variety of circumstances including radiation, damage from environment chemicals, and aging. Natural and pharmacological prevention of free radical damage is being actively investigated.	Free Radical
D000323	Adrenochrome	Pigment obtained by the oxidation of epinephrine.