Investigation of the synthesis and antioxidant activity of novel derivatives of the natural compound daidzein and the quantitative structure–activity relationships

To investigate the relationship between the antioxidant capacity and structure of daidzein, a series of derivatives were synthesised. The results from DPPH and ABTS radical scavenging assays indicated that 4'-hydroxy modified daidzein derivatives exhibited no free radical scavenging ability. In contrast, the daidzein derivative with 7-hydroxy modification retained or enhanced its free radical scavenging rate. Notably, derivatives 3-(4-hydroxyphenyl)-7-((4-(trifluoromethyl)benzyl)oxy)-4<i>H</i>-chromen-4-one (<b>3s</b>) and 7-((2,6-dimethylbenzyl)oxy)-3-(4-hydroxyphenyl)-4<i>H</i>-chromen-4-one (<b>4h</b>) demonstrated exceptional DPPH and ABTS radical scavenging capabilities, achieving rates exceeding 80% in both assays. Furthermore, quantitative structure-activity relationships (QSAR) for daidzein derivatives have been explored, providing valuable insights for future research endeavours.