Synthesis and evaluation of acetylferulic paeonol ester and ferulic paeonol ester as potential antioxidants to inhibit fish oil oxidation.

Acetylferulic paeonol ester (APE) and ferulic paeonol ester (FPE) were synthesized, and their structures were confirmed by NMR, mass spectra, IR and UV-vis data. The antioxidant properties of the synthesized compounds were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and [(2-azino-bis (3-ethylbenzthiazoline)-6 -sulfonic acid] (ABTS) assay as well as the production of oxidation products (peroxides, conjugated dienes, thiobarbituric acid-reactive substances, free fatty acids and total aldehydes) in an elevated temperature (60 °C) storage trial of fish oil extracted from anchovy. Furthermore, the changes in fatty acid composition were monitored by gas chromatography-mass spectrometry. The results showed that APE was more effective in restraining fish oil oxidation compared to FPE, ferulic acid, paeonol and the commercial antioxidant-butylated hydroxytoluene (BHT). This study demonstrated molecular combinations obtained by covalent bonding two antioxidant active molecules can result in novel compounds with enhanced antioxidant activities.