Inorganic Radicals of Relevance to Biological Systems [and Discussion]

• Published in: Philosophical transactions of the Royal Society of London. Series B, Biological sciences Biological sciences, 1985-12, Vol.311 (1152), p.451-472
• Main Authors: Symons, M. C. R., Sies, H.
• Format: Article
• Language: English
• Subjects: Animals; Anions; Biological and medical sciences; Electron Spin Resonance Spectroscopy; Electrons; Free Radicals; Fundamental and applied biological sciences. Psychology; Humans; Hydrogen; Hydroxides; Ions; Magnetic fields; Magnetic Resonance Spectroscopy; Mechanisms. Catalysis. Electron transfer. Models; Metals; Molecular biophysics; Molecules; Nitrogen Oxides; Oxygen; Peroxides; Physical chemistry in biology; Reactivity; Solvation; Spectroscopy; Spin Labels; Sulfur; Superoxides
• ISSN: 0962-8436; 0080-4622; 1471-2970; 2054-0280
• DOI: 10.1098/rstb.1985.0157

There is little doubt that the most important inorganic radicals involved in biological systems are those which are intermediates in the oxygen-water redox cycle, i.e. OH$^\cdot$, O$^-_2$ and HO$^\cdot_2$. Aspects of the structures and reactivities of these radicals are considered, together with methods of detection. In particular, the use of e.s.r. spectroscopy is outlined, including rapid-freeze and spin-trapping techniques. Attention is called to comparisons and contrasts between these radicals and corresponding sulphur-centred radicals, although these are not strictly 'inorganic'. The oxygen-centred radicals are usually generated in vivo by redox reactions, but they are also of importance in radiolytic processes because they are formed from water. Other radicals formed in this way whose structures and reactivities are considered include solvated electrons and hydrogen atoms.