Substituted pyridoindoles as biological antioxidants: drug design, chemical synthesis, and biological activity.

Great effort has been devoted to design and synthesize biologically active and pharmacologically acceptable antioxidants. Although a number of efficient antioxidant compounds have been designed, synthesized, and tested in animals, none of them have demonstrated sufficient efficacy in human clinical trials without undesirable side effects. Thus new pharmacologically applicable antioxidants have been sought for. Substituted pyridoindoles represent a broad spectrum of pharmacologically active substances including highly effective scavengers of reactive oxygen species. The hexahydropyridoindole scaffold represents a valuable lead with a great deal of knowledge on molecular mechanisms of free radical scavenging, on bioavailability and toxicity. Its modification may yield congeners tailored according to specific requirements for antiradical efficacy, lipophilicity, and basicity, meeting the aim of providing a pharmacologically practicable antioxidant drug as exemplified by the novel derivative SMe1EC2.