| 摘要: | 中藥鈎藤Uncaria rhynchophylla (Miq.) Jacks.的帶鈎枝條以乙醇進性抽提，抽提物經分配萃取共得到正己烷層、甲醇層、正丁醇層及水層，進行有效成分分離及其在化妝品方面之生物活性試驗，共得到15個化合物。Triterpenoid類: Ursolic acid (1) 和Oleanolic acid (2); Flavonoid類: (-)-Epicatechin (3) 和Quercetin (4); Phenolics 類: Syringic acid (5)、Caffeic acid (6)、Protocatechuic acid (7)和Vanillic acid (8); Phenolic acid ester類: Methyl chlorogenate (9); Coumarin類: Scopoletin (10); Sterol類: β-Sitosteryl-β-D-glucoside (11)和β-Sitosterol (13)及Aliphatic類: Methyl hexadecanoate (12)、Eicosanoic acid (14)和Stearyl stearate (15)。上述化合物經各種光譜分析加以證明及確認其化學結構式，化合物2、6、7、8、9、12、14 及 15為首次從鈎藤純化分離得到之成分。
從鈎藤純化分離得到之具有降低B16黑色素細胞內黑色素含量生物活性的化合物為(-)-Epicatechin (3)、Quercetin (4)、Caffeic acid (6)、Methyl chlorogenate (9)、β-Sitosteryl-β-D-glucoside (11)及β-Sitosterol (13) 其中以化合物3及4濃度分別為100 µg/mL 及 25µg/mL降低黑色素含量效果最為顯著，其含量率分別為30.39 % 及 9.93 %。另外，具有清除DPPH自由基生物活性的化合物為(-)-Epicatechin (3)、Quercetin (4)、Syringic acid (5)、Caffeic acid (6)、Protocatechuic acid (7) 及Methyl chlorogenate (9)清除DPPH自由基活性(SC50值分別為4.03、2.10、1.68、2.17、1.87及2.92 μg/mL)均比L-Ascorbic acid (SC50值為5.65 μg/mL)強。
The antioxidation and antimelanogensis activities of Uncaria rhynchophylla-derived materials were evaluated. The ethanol extract of U. rhynchophylla was partitioned into n-hexane, methanol, BuOH, and water. The n-hexane and methanol soluble partition exhibited antioxidation and antimelanogensis activities, and further purified by CC, Sephadex LH-20, Lobar RP-8, and HPLC. The bioassay guided purification to get fifteen compounds: ursolic acid (1), oleanolic acid (2), (-)-epicatechin (3), quercetin(4), syringic acid (5), caffeic acid (6), protocatechuic acid (7), vanillic acid (8), methyl chlorogenate (9), scopoletin(10), β-sitosteryl-β-D-glucoside (11), β-sitosterol (13), Methyl hexadecanoate (12), eicosanoic acid (14), and Stearyl stearate (15) from U. rhynchophylla. Of these fifteen compounds, 2, 6, 7, 8, 9, 12, 14, and 15 are identified for the first time from U. rhynchophylla. Six isolated compounds showed inhibitory activity melanin content of melanoma B16 cells of (-)-epicatechin (3), quercetin (4), caffeic acid (6), methyl chlorogenate (9), β-sitosteryl-β-D-glucoside (11), and β-sitosterol (13). Compounds 3 and 4 showed potent antimelanogensis activity with an concent value of 30.39 and 9.93 %. The compounds (-)-epicatechin (3), quercetin (4), syringic acid (5), caffeic acid (6), protocatechuic acid (7), methyl chlorogenate (9) showed DPPH free radical scavenging activity with the SC50 values of 4.03, 2.10, 1.68, 2.17, 1.87, and 2.92 μg/mL, respectively. All of them exhibited higher activity than ascorbic acid (5.65 μg/mL). |
