Sulfonamide a Valid Scaffold for Antioxidant Drug Development

Like the well-known sulfa drugs, Sulfonamides are ascribed to a myriad of biological activities, including antioxidant activity. In fact, several tertiary sulfonamides, particularly N, Ndisubstituted analogues, are recognized as antioxidants that can prevent or minimize oxidative damage associated with several oxidative-stress-related diseases. The structural diversity of this class of compounds paved the way for drug discovery programs aimed at finding therapeutic agents. Attributes such as low-cost synthetic procedures, easy accessibility of reagents, and a broad spectrum of biological activities made sulfonamides and derivatives excellent candidates for synthesizing chemical libraries with structural diversity. Sulfonamide-based drugs are most of the sulfur-containing drugs approved by the United States Food and Drug Administration (FDA). Although sulfonamide derivatives have been extensively exploited as antibacterial agents, their therapeutic potential as antioxidants is relatively underexplored despite the prevalence of oxidative stress-mediated diseases and the urgent need for new and more effective antioxidant drugs. Some sulfonamide derivatives were shown to activate the nuclear factor erythroid 2-related factor 2 (Nrf2), the main regulator of the endogenous antioxidant response, a critical process used by cells in response to oxidative stress. The antioxidant role of sulfonamides and derivatives as Nrf2 activators is also reviewed. The antioxidant mechanism of action of sulfonamides has not been fully clarified, but as they have antioxidant properties, it is a subject worthy of in-depth study. The present review is focused on sulfonamides and derivatives as potential antioxidants along the period 2013-2021 and intends to stimulate research in the area.