Interaction of Phenolic Schiff Bases Bearing Sulfhydryl Moieties with 2,2-Diphenyl-1-picrylhydrazyl Radical: Structure–Activity Relationship Study

Abstract

Current research on synthetic and naturally occurring phenolic compounds is centered around their prominent antioxidant properties. Since reactive oxygen (ROS) and nitrogen (RNS) species cause considerable damage to cellular components upon their overproduction, associated with the pathogenesis of degenerative, cardiovascular and oncological diseases, antioxidants may reduce the risk of developing such conditions. Because hydroxyl, amino and sulfhydryl groups present in their structure, antioxidants may function as hydrogen atom and electron donors, as well as metal-reducing and metal-chelating agents. We synthesized phenolic Schiff bases from 4,6-di-tert-butyl-2,3-dihydroxybenzaldehyde; ortho-, meta- and para-mercaptoanilines; and 2,2′- and 4,4′-disulfanediyldianilines. Their antioxidant properties were studied in a 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging assay.

Keywords

• Schiff bases
• DPPH
• antioxidant activity
• thiols
• phenolic compounds