Synthesis, characterization and antioxidant activity of organoselenium and organotellurium compound derivatives of chrysin†
Herein we describe the results on the synthesis and the evaluation of the antioxidant activity of several organochalcogen-containing chrysin derivatives (Se and Te). The semi-synthetic compounds were easily synthesized in good to excellent yields by the reaction of 7-(2-bromoethoxy)-chrysin with nucleophilic organoselenium and organotellurium species. The antioxidant properties of Se- and Te-containing chrysin derivatives were evaluated by three different in vitro assays, the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activities and ferric ion reducing antioxidant power (FRAP). Compounds 4i (which contains the butyltellurium moiety) and 4j (which contains a 4-phenyltellurium moiety) exhibited higher activities than chrysin and the selenium analogues, with compound 4i being the most potent antioxidant.