Synthesis, structure, and antioxidant activity of methoxy- and hydroxyl-substituted 2'-aminochalcones

Three 2'-aminochalcone derivatives (E)-1-(2-aminophenyl)-3-(4-hydroxyphenyl)prop-2-en-1-one, (E)-1-(2-aminophenyl)-3-(3,4-dihydroxyphenyl)prop-2-en-1-one, and (E)-1-(2-amino-4,5-dimethoxyphenyl)-3-(4-methoxyphenyl)prop-2-en-1-one, have been synthesized, characterized, and tested in vitro in order to assess their antioxidant activity. All compounds were characterized on the basis of 1H NMR, 13C NMR, ESI-mass spectrometry, FT-IR, UV/Vis, and elemental analysis. The X-ray crystal structures of (E)-1-(2-aminophenyl)-3-(4-hydroxyphenyl)prop-2-en-1-one and (E)-1-(2-amino-4,5-dimethoxyphenyl)-3-(4-methoxyphenyl)prop-2-en-1-one were successfully determined showing a planar molecule geometry. Studies on the biological properties including test of free radical scavenging ability (DPPH test) and superoxide dismutase mimetic activity were performed. The results indicate that the aminochalcone carrying two hydroxyl functionalities in adjacent meta and para position exhibits a stronger antioxidant activity than the other derivatives.