PROBLEM TO BE SOLVED: To provide an endothelin action inhibitor, a whitening agent and a skin external preparation.SOLUTION: The endothelin action inhibitor, a whitening agent and a skin external preparation include a compound represented by general formula (1) or its salt as an active constituent wherein, R denotes a hydrogen atom or a 1 to 4C alkyl group.COPYRIGHT: (C)2013,JPO&INPIT【課題】エンドセリン作用抑制剤、美白剤及び皮膚外用剤を提供する。【解決手段】下記一般式(1)で表される化合物又はその塩を有効成分として含有するエンドセリン作用抑制剤、美白剤及び皮膚外用剤。(式中、Rは水素原子又は炭素原子数1~4のアルキル基を表す。)【選択図】なし
