(一) 樟葉槭之成分研究 (二) 兒茶酚衍生物於人類黑色素細胞活性探討

(1) The constituents from Acer albopurpurascens Hayata (2) The activities of catechol derivatives in human epidermal melanocytes

黃靜儀(Ching-Yi Huang)

指導教授 ： 李美賢

臺北醫學大學/藥學院/生藥學研究所/碩士(2010年)

摘要

樟葉槭 (Acer albopurpurascens Hayata) 為楓科 (Aceraceaez) 常綠喬木，台灣特有種，分布於台灣全島低至中海拔山區。本論文第一部分乃採集樟葉槭之葉部，以95%乙醇萃取，進行成分分離。經管柱層析分離純化得到七個化合物，經由光譜分析與文獻比對。結構為
chlorgenic acid methyl ester (1)、(-)-epicatechin (2) tricin-7-O-β-D-glucopyranoside (3)、tricin-4´-O-β-D-glucopyranoside (4)、quercetin (5)、dendratnhemoside
A (6) 和 dihydrodendranthemoside A (7)。第二部分為探討由白花水竹草 (Trandescantia albiflora Kunth) 所分出七種兒茶酚
(catechol) 化合物及其半合成衍生物，對人類正常黑色素細胞抑制黑色素生成的活性。此十六種化合物於100 μM濃度下對於人類正常黑色素細胞之細胞存活率皆大於80%，進一步進行細胞內酪胺酸酵素活性測試，結果顯示化合物AR9 及AR10 具最佳之酪胺酸酵素抑制活性，其 IC50 分別為 81.1及 90.7 μM；以西方墨點法分析，結果顯示AR9 具有抑制酪胺酸酵素和酪胺酸相關蛋白酵素-2 蛋白質之表現，而AR10 具有抑制酪胺酸酵素蛋白質之表現，對於酪胺酸相關蛋白酵素-1 及酪胺酸相關蛋白酵素-2 則無明顯作用。另外以細胞免疫染色法觀察亦有相同的結果。

關鍵字

樟葉槭 ； 台灣特有種 ； 人類黑色素細胞 ； 酪胺酸酵素

並列摘要

Acer albopurpurascens Hayata is an evergreen and endemic species in Taiwan. It was found widely throughout the island and from the low lands up to an altitude of 1800 m. The fresh leaves of A. albopurpurascens were extracted with 95% ethanol at room temperature. After filtering and
concentrating under reduced pressure, the 95% ethanolic extraet was partitioned with a sequence of n-hexane, ethyl acetate (EtOAc), and n-butanol (n-BuOH), and water to give four fractions. The EtOAc and n-BuOH extracts were subject to gel filtration and reversed-phase chromatography to obtain seven known compounds. These known
compounds were identified as chlorgenic acid methyl ester (1), (-)-epicatechin (2), tricin-7-O-β-D-glucopyrano-side (3), tricin-4´-O-β-Dglucopyranoside (4), quercetin (5), dendranthemoside A (6) and dihydrodendranthemoside A (7) by comparison of spectroscopic data of the literature or authentic sample.
Part 2 is study seven compounds isolated from Trandescantia albiflora Kunth and five compounds of catechol derivatives by chemical synthesis. Those 16 compounds were further evaluated their abilities to inhibit cellular melanin synthesis in human epidermal melanocytes (HEMn). Cell viabilities of 16 compounds were higher then 80%, when cells were treated with 100 μM of different compounds. The 16 compounds were further evaluated their cellular tyrosinase activity in HEMn, and the compounds AR9 and AR10 were the most potent in inhibiting tyrosinase activity. The copmounds AR9 and AR10 IC50 were 81.1 and 90.7 μM respective. Results of the protein expression of cellular tyrosinase and TRP-2 showed AR9 X possessed significant inhibitory effects by blotting analysis, and tyrosinase
showed AR10, too.

並列關鍵字

Acer albopurpurascens Hayata ； endemic species in Taiwan ； human epidermal melanocytes ； tyrosinase

參考文獻

22.Hsieh, T.J., Wu, Y.C. & Chen, C.Y. Chemical constituents from the leaves of Epimedium sagittatum. Chinese Pharmaceutical Journal (Taipei, Taiwan) 55, 121-128 (2003).

3.Akazawa, H., Akihisa, T., Taguchi, Y., Banno, N., Yoneima, R. & Yasukawa, K. Melanogenesis inhibitory and free radical scavenging activities of diarylheptanoids and other phenolic compounds from the bark of Acer nikoense. Biological and Pharmaceutical Bulletin 29, 1970-1972 (2006).

4.Yang, H., Sung, S. H. & Kim, Y. C. Two new hepatoprotective stilbene glycosides from Acer mono leaves. Journal of Natural Products 68, 101-103 (2005).

5.Kim, H. J., Woo, E.R., Shin, C.G. & Park, H. A new flavonol glycoside gallate ester from Acer okamotoanum and its inhibitory activity against human immunodeficiency virus-1 (HIV-1) integrase. Journal of Natural Products 61, 145-148 (1998).

6.Jin, W., Min, B.S., Lee, J., Thuong, P. T., Lee, H.K., Song, K., Seong, Y. H. & Bae, K. Isolation of constituents and anti-complement activity from Acer okamotoanum. Archives of Pharmacal Research 30, 172-176 (2007).