PROBLEM TO BE SOLVED: To obtain a melanin generation suppressing agent consisting of a specific calamenene and useful for producing a skin preparation for external use such as a cosmetic having melanin generation suppressing activity. ;SOLUTION: A melanin generation suppressing agent consisting of a calamenene of formula I (R1 is H, OH or a 1-4C alkoxy), preferably 7- methoxycalamenene of formula II. The calamenene is contained in a large amount in a plant or the like as a natural product. Especially, the compound of formula II is contained for example, in a plant of Aristolochiaceae such as Aristolochia debilis in a large amount. The objective compound is obtained by adding a solvent such as methanol to plant bodies of said plant, immersing them in the solvent for several days in the case of room temperature, concentrating the filtrate and purifying the concentrate by silica gel chromatography or the like. The objective skin preparation for external use is preferably prepared by compounding the suppressing agent. The skin preparation for external use is useful as a beautifying cosmetic. The content of a compound of formula I in the skin preparation for external use is preferably 0.05-1 wt.% in terms of the total amount.;COPYRIGHT: (C)2000,JPO
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