Novel Mannich bases of α- and γ-mangostins: Synthesis and evaluation of antioxidant and membrane-protective activity.

A series of new C-4- and C-4/C-5-aminomethyl derivatives were synthesized on the basis of α- and γ-mangostins. A comparative evaluation of their chelating ability, radical scavenging activity and hemolytic activity, as well as antioxidant and membrane-protective properties, was carried out on the model of H2O2-induced hemolysis of mammalian red blood cells. It was shown that γ-mangostin and its C-4/C-5-derivatives were superior to α-mangostin and its derivatives in all the investigated parameters characterizing the antioxidant activity in the test systems used. Most of the synthesized Mannich bases at low concentrations were superior to the original α- and γ-mangostins in the ability to protect mammalian red blood cells under H2O2-induced oxidative stress conditions.