摘要：Melanogenesis inhibitory and free radical scavenging activities of nine cyclic (1—9) and one acyclic diarylheptanoids (10), and two phenolic compounds, (+)-rhododendrol (11) and (+)-catechin (12), isolated from the ethyl acetate-soluble fraction of the MeOH extract of the bark of Acer nikoense M AXIM . (Aceraceae) were examined. Upon evaluation of compounds 1—12 on the melanogenesis in the B16 melanoma cells, two compounds, 2 and 8, exhibited marked inhibitory activity with 55.6% and 46.8% reduction, respectively, of melanin content at 25 μg/ml without inhibition of cell proliferation. In addition, upon an evaluation of eleven compounds, 1—7 and 9—12 against the scavenging activities of free radicals (against the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical), compound 12 (IC50 9.0 μ M ) followed by compounds 1, 3, 4, and 6 (IC50 40.2—44.0 μ M ) showed potent scavenging activities.
