Isobornylchalcones and flavones derived from them: synthesis and antioxidant activity

Methoxychalcones containing the NMe₂, 3,4-(OMe)₂, 3,4,5-(OMe)₃, and isobornyl substituents in the B ring were synthesized from 1,3-dihydroxy-4-(1,7,7-trimethylbicyclo-[2.2.1]hept-exo-2-yl)benzene and 1,4-dihydroxy-3-(1,7,7-trimethylbicyclo[2.2.1]hept-exo-2-yl)benzene. Oxidative cyclization of the new isobornylchalcones afforded flavones bearing the 1,7,7-trimethylbicyclo[2.2.1]hept-exo-2-yl moiety. The erythrotoxicity, membrane-protective, and antioxidant activity of the synthesized compounds were evaluated in in vitro models including the model of oxidative hemolysis of mammalian erythrocytes initiated by H₂O₂ or 2,2′-azobis-(2-amidinopropane) dihydrochloride. All the chalcones studied and most flavones possessed good hemocompatibility and high antioxidant activity. The promise of further research into the synthesis of effective pharmacological substances based on the title compounds was demonstrated.