Eugenol, isoeugenol, caŠeic 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 eŠect 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 eŠects of eugenol, isoeugenol, and the glycoside derivatives of caŠeic acid, ferulic acid, and isoferulic acid (SC 50 ＝8-28 mM) were similar to those of a-tocopherol, which was used as a positive control.

Plant-derived phenylpropanoid compounds (4-ethyl-2-methoxyphenol, 2,6-dimethoxyphenol, 2,3-dimethoxyphenol, 3,4-dimethoxyphenol, 3,5-dimethoxyphenol, 3,4-dihydroxycinnamic acid, 4-hydroxy-3-methoxycinnamic acid, and 3-hydroxy-4-methoxycinnamic acid) were glycosidated to form glycoside compounds. We evaluated the eŠects of these compounds on the inhibition of tyrosinase and melanin synthesis and their cytotoxicity from the viewpoint of their use as whitening agents in cosmetics. Some compounds had more potent tyrosinase-inhibiting activity than commercial arbutin, which was used as a control, and showed no cytotoxicity at low concentration ranges.