DPPH radical-scavenging effect of several phenylpropanoid compounds and their glycoside derivatives

Eugenol, isoeugenol, caffeic acid, ferulic acid, isoferulic acid, estragole, trans-anethole, and paeonol are components of a Chinese herbal medicine used as a painkiller and stomachic. We investigated the potential role of these compounds as antioxidants. We studied the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical-scavenging effect of these molecules, together with some glycoside derivatives, to ascertain their potential in reducing the levels of activated oxygen species in vivo. The DPPH radical-scavenging effects of eugenol, isoeugenol, and the glycoside derivatives of caffeic acid, ferulic acid, and isoferulic acid (SC50=8-28 mu M) were similar to those of a-tocopherol, which was used as a positive control.