Accession Number : ADA323481

Title :   Efficient Scavenging of Superoxide Radical (02-) in Vitro and In Vivo.

Descriptive Note : Annual rept. 8 May 95-7 May 96,

Corporate Author : DUKE UNIV MEDICAL CENTER DURHAM NC

Personal Author(s) : Fridovich, Irwin

PDF Url : ADA323481

Report Date : JUN 1996

Pagination or Media Count : 18

Abstract : We have prepared manganic porphyrins, as mimics of SOD activity. Several generalizations follow: (a) In vivo action may involve cycles of reduction by NAD(P)H, or GSH, and reoxidation by O2; whereas the in vitro cycle involves O2 in both reduction and oxidation steps. (b) Action of mimics on bacterial cells is only a rough indicator of their action on mammalian cells; because of differences in uptake of the compounds. (c) Redox potential is more important than net charge, for activity in the in vitro assay. The most active compound we have prepared to date is the Mn(III) 2,3,7,8,12,13,17, 18-octabromo-5, 10, 15,20-tetrakis (N-methyl pyridinium-4-yl)porphyrin. Since the electron withdrawing effect of Br<Cl<F, we will also explore the synthesis and properties of the octachloro and octafluoro analogues. Bromination increased the rate constant by -50-fold. Chlorination or fluorination might provide even greater improvements.

Descriptors :   *IN VITRO ANALYSIS, *IN VIVO ANALYSIS, *CELLS(BIOLOGY), *OXIDATION REDUCTION REACTIONS, *SUPEROXIDES, MAMMALS, SYNTHESIS, BACTERIA, ELECTRONS, CHLORINATION, INDICATORS, ROUGHNESS, ASSAYING, FLUORINATION, GRASSES, BROMINATION, PORPHYRINS.

Subject Categories : Biochemistry
      Anatomy and Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE