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Table 1 Equations

From: Oxidation in rheumatoid arthritis

Oxygen radical generation
   NADPH oxidase: 2O2 + NADPH 2O2•- (superoxide) + NADPH+ + H+
   Spontaneous conversion: 2O2•- + 2H+ [2HO2 (hydroperoxyl radical)] → O2 + H2O2
   Superoxide dismutase: 2O2•- + 2H+ O2 + H2O2
   Myeloperoxidase: Cl- + H2O2 OCl- (oxidised halide) + H2O
Reactive oxygen species secondary products
  H2O2 + Fe2+ OH- + OH (hydroxyl radical) + Fe3+
  Fe3+ + O2•- O2 + Fe2+
  O2•- + HOCl O2•- + OH + Cl-
  H2O2 + OCl- 1O2 (singlet oxygen) + H2O + Cl-
  NH3 + HOCl NH2Cl (chloramine) + H2O
  R-CHNH2-COOH + HOCl → R-CHNHCl-COOH + H2O → R-CHO + CO2 + NH4+ + Cl-
  (amino acids) (chloramines) (aldehydes)
Nitrogen radical generation and secondary reactions
   Nitric oxide synthetase: arginine + O2 + NADPH NO + citrulline + NADP+
  NO + O2•- ONOO- (peroxynitrite)
  ONOO- + H+ ONOOH (peroxynitrous acid)
  ONOOH (peroxynitrous acid) NO3- (nitrate ion)
  ONOOH NO2+ (nitronium ion)
  ONOOH NO2 (nitrogen dioxide radical)
  ONOOH OH-
  ONOOH OH (hydroxyl radical)
Lipid peroxidation
  LH + Radical L + RH
  L + O2 LOO (lipid peroxyl radical)
  LH + LOO L + LOOH (leading to lipid propagation)
  LOO + TocOH (α-tocopherol) LOOH + TocO (chain termination)