Melanogenesis Inhibitory and Free Radical Scavenging Activities of Diarylheptanoids and Other Phenolic Compounds from the Bark of Acer nikoense

• Published in: Biological & Pharmaceutical Bulletin Vol. 29; no. 9; pp. 1970 - 1972
• Main Authors: Akazawa, Hiroyuki, Akihisa, Toshihiro, Taguchi, Yosuke, Banno, Norihiro, Yoneima, Risa, Yasukawa, Ken
• Format: Journal Article
• Language: English; Japanese
• Published: Japan The Pharmaceutical Society of Japan 01.09.2006; Pharmaceutical Society of Japan; Japan Science and Technology Agency
• Subjects: Acer - chemistry; Acer nikoense; Animals; antioxidant activity; diarylheptanoid; Diarylheptanoids - pharmacology; Free Radical Scavengers - pharmacology; Melanins - biosynthesis; melanogenesis; Mice; Phenols - pharmacology; Plant Bark - chemistry; Plant Extracts - pharmacology; radical scavenging
• ISSN: 0918-6158; 1347-5215
• DOI: 10.1248/bpb.29.1970

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 MAXIM. (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 μM) followed by compounds 1, 3, 4, and 6 (IC50 40.2—44.0 μM) showed potent scavenging activities.