PROBLEM TO BE SOLVED: To provide isolation of a useful new compound comprised in Brasenia schreberi, and a skin-beautifying agent and the like containing the compound.SOLUTION: A heat extraction method where a solvent (for example, ethanol) is added to Brasenia schreberi, followed by warming/heating to the degree of not-deactivating an active ingredient included in an extract, a supercritical extraction method and the like can be appropriately used. In addition, known various extraction methods such as an immersion extraction method where a bark of Brasenia schreberi immersed in a constant amount of solvent for batch processing, and a continues extraction method where a solvent is continuously sent are used. From an extract liquid obtained, an active fraction can be fractionated. Further, according to necessity, suitable separation purification means such as alumina column chromatography and silica gel chromatography, gel filtration chromatography, ion exchange chromatography, hydrophobic chromatography, and high performance liquid chromatography are combined for purification to obtain 3-O-(6"-O-E-caffeoyl)-b-D-glucopyranosid.【課題】ジュンサイに含まれる有用な新規化合物を単離すること、及び当該化合物を含有する美肌剤等の提供。【解決手段】ジュンサイに溶媒（例えば、エタノール）を加えた後、抽出物に含まれる活性成分の活性を失活させない程度に加温加熱する加熱抽出法や、超臨界抽出法等を適宜適用できる。また、一定量の溶媒にジュンサイの樹皮を浸漬してバッチ処理する浸漬抽出法や連続的に溶媒を送り続ける連続抽出法等、公知の種々の抽出法を適用する。得られた抽出液から活性画分を分取することができる。更に、必要に応じて、アルミナカラムクロマトグラフィーやシリカゲルクロマトグラフィー、ゲルろ過クロマトグラフィー、イオン交換クロマトグラフィー、疎水クロマトグラフィー、高速液体クロマトグラフィー等の適当な分離精製手段を組み合わせて精製し、3-O-(6"-O-E-caffeoyl)-b-D-glucopyranosidを得た。【選択図】なし
