Antioxidant activity of sinapic acid anilides: DPPH, ABTS, FRAP, electrochemical and theoretical analysis
Viviana Donoso-Bustamante, Edison Osorio, María Fernanda Arias‐Santé, Adriano Costa de Camargo, Miguel Ángel Rincón‐Cervera, John Amalraj, Basilio Carrasco, Iván Palomo, Ramiro Araya‐Maturana
Abstract
Sinapic acid (SA) and ferulic acid (FA) are known antioxidants; however, their hydrophilic nature results in poor bioavailability. In contrast, their alkyl esters, with greater lipophilicity, exhibit lower activity than their precursors. This study reports the antioxidant behavior of some synthetic anilides derived from SA and FA, as analyzed using DPPH, ABTS, and FRAP spectrophotometric methods, along with differential pulse and cyclic voltammetry techniques. Electronic structure calculations were employed to investigate the electrochemical behavior and the antioxidant mechanisms. Two derivatives demonstrate superior antioxidant activity compared to the SA precursor: C5, the most effective in the FRAP assay, and C4, the most effective in the DPPH and ABTS assays. Interestingly, compound C7 exhibited higher antioxidant activity than FA. Theoretical analysis suggests that these compounds can be classified as effective radical scavengers. Ultimately, this research underscores the synthesis of new and more active antioxidants from natural precursors, studying their characteristic reactivity patterns. • The common bean or Phaseolus vulgaris L. is a rich source of bioactive and antioxidant compounds. • Anilides synthesized from sinapic acid and ferulic acid are potential antioxidants. • Methods such as DPPH, ABTS, FRAP, electrochemical methods, and theoretical analysis were used to determine antioxidant activity.