INHIBITION OF OXIDATION OF AROMATIC-AMINES IN HEME-CONTAINING HYDROGEN-PEROXIDE SYSTEMS BY SUBSTITUTED 4,6-DI-TERT-BUTYL-PYROCATECHOLS

The substituted pyrocatechols sodium (2,3-dihydroxy-4,6-di-tert-butyl- phenyl) (InH1) and 3-(S-glutathionyl)-4,6-di-tert-butyl-pyrocatechol ( InH2) effectively inhibited oxidation of o-phenylenediamine and tetram ethylbenzidine (TMB) catalyzed by hemin or its complex with BSA (methe malbumin). The method of competitive reactions of aromatic amines (PDA , TMB) and pyrocatechols (InH1, InH2) with active radicals was used fo r the quantitative determination of rates of radical initiation in sys tems containing hemin (methemalbumin) and H2O2 (TBHP). The use of the inhibitor method for heme-protein-peroxide systems is complicated by h eterogeneity of the radicals generated (HO., RO., HO2., RO2., peroxide -like compounds I and II), formation of complexes of the inhibitors wi th protein component, and possible interaction of active radicals with organic co-solvents (DMF or DMSO). The system hemin (methemalbumin)-H 2O2 (TBHP)-aromatic amines can be used for testing the efficacy of pot ential bioantioxidants.