本研究以中藥益智(Alpinia oxyphylla Miq.)之乾燥果實進行有效成分之純化分離，並將其成分進行美白及抗氧化之試驗。益智萃取物進行色層層析的方法進行其純化分離，共得到8種純化合物為：Vanillic acid (1) Oxyphyllenone A (2)、Oxyphyllenodiol B (3)、Yakuchinone A (4)、Tectochrysin (5)、1, 2-Divanillylethane(6)、AOE-6 (7) 及AOE-21 (8)。上述化合物經由各種光譜鑑定其化學結構式。化合物1 、7及8為首次從益智植物中分離得到。
此8個化合物利用MTT分析測定對其細胞毒性之安全濃度，在B16 黑色素細胞內之濃度0-50 μg/mL是沒有毒性，在其安全濃度之下進行抑制黑色素之試驗，其結果顯示化合物8有抑制B16黑色素細胞黑色素生成之作用；但化合物8再進行胞外抑制酪氨酸酶之活性分析試驗，其實驗結果並不理想，與正對照組和麴酸相比較抑制酪氨酸酶活性之作用差。因此，化合物8其美白功效可能是透過其他的方式(如基因或傳遞訊息)來達到美白效果。 在抗氧化之實驗結果顯示8個化合物1、2、4、6及8有明顯清除DPPH自由基之作用，且化合物4及6的SC50值分別為3.79及4.81 μg/mL清除DPPH自由基之作用比L-Ascorbic acid(SC50值為5.65 μg/mL) 強。 In this study, the dry fruit of Yizhi (Alpinia oxyphylla Miq.) isolated active ingredients for antimelanogensis and antioxidation. Chemical reinvestigation of Yizhi led to the isolation and characterization of the following compounds: vanillic acid (1), oxyphyllenone A (2), oxyphyllenodiol B (3), yakuchinone A (4), tectochrysin (5), 1, 2-divanillylethane (6), AOE-6 (7) and AOE-21 (8). Their structures were elucidated by spectroscopic methods. Among them, compound 1, 7 and 8 are isolated for the first time from Yizhi. The eight compounds safe concentrations were determined by MTT assay. Skin-whitening capacity in skin melanoma B16 cells and in vitro tyrosinase test for 8 compounds were investigated. The compound 8 is non-toxic in concentrations of 0-50 μg/mL and the results significant inhibit in melanoma B16 cells. The compounds 1, 2, 4, 6, and 8 showed significant inhibited DPPH free radical scavenging activity. Among them, compounds 4 and 6 of exhibited with SC50 values 3.79 and 4.81 μg/mL higher activities than ascorbic acid (5.65 μg/mL).
