Antioxidant Activity of a New Series of Carbazole-Derived Nitrones

A new series of 2- and 4-substituted carbazole-derived nitrones was synthesized and evaluated for their antioxidant properties using multiple in vitro protocols, including inhibition of AAPH-induced lipid peroxidation, hydroxyl radical scavenging, ABTS•+–decolorization and DPPH interaction assays. Their anti-inflammatory capacity was investigated through the inhibition of soybean lipoxygenase (SLOX). Among all fourteen tested nitrones, compound 11bg emerged as the most promising derivative, exhibiting strong inhibition of lipid peroxidation and efficient hydroxyl radical scavenging activity. Nitrone 11be showed the highest lipoxygenase inhibition with an IC50 value of 0.0225 μM. Furthermore, seven of the fourteen synthesized hybrids showed strong SLOX inhibitory activity, with IC50 values below 30 μM.