Radical scavenging properties of nicotinamide and its metabolites

By means of pulse radiolysis the reactivity of nicotinamide, its metabolites and selected pyridinium salts towards reactive oxygen species was tested and compared with the pharmacological efficacy of this group of compounds. It was found that pyridinium salts are poor radical scavengers but the positive charge distribution enhances their interactions with immobilized heparin. Thus, superior pharmacological efficacy of 1-methylnicotinamide may be related to its ability to interact with biological tissues rather than to its direct anti-oxidant properties.