鴨舌癀地上部之美白及抗氧化成分研究

Whitening and Antioxidative Constituents from the Aerial Part of Phyla nodiflora

陳佩君(Pei-Chun Chen)

指導教授 ： 林忠男

高雄醫學大學/藥學院/藥學研究所/碩士(2009年)

摘要

本篇研究目標為由天然物分離得到具酪胺酸酶抑制及抗氧化活性之化合物，預試驗發現天然物鴨舌癀（Phyla nodiflora）地上部之甲醇萃取物有總酚類含量及良好的抗酪胺酸酶及自由基清除之活性，進行成分分離後得到五個已知化合物，分別為eupafolin（1）、hispidulin（2）、larycitrin（3）、β-sitosterol（4）及stigmasterol（5）；將eupafolin（1）及hispidulin（2）進行抑制酪胺酸酶實驗，發現皆具有良好的抑制效果，其中針對較強力活性的eupafolin（1）（IC50 = 56.0 μM）進行酵素動力學實驗結果發現，eupafolin（1）為競爭型抑制酪胺酸酶；自由基清除能力試驗方面，將eupafolin（1）及hispidulin（2）進行1,1-diphenyl-2-picryhydrazyl（DPPH）、2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid（ABTS）及超氧陰離子（superoxide anion）自由基清除活性試驗，hispidulin（2）對於DPPH•及 ABTS•＋自由基有清除效果，而eupafolin（1）對三種自由基都有優良的清除活性，在黃嘌呤氧化酶酵素動力學實驗結果顯示，eupafolin（1）是以混合型抑制模式抑制黃嘌呤氧化酶。

關鍵字

鴨舌癀酪胺酸酶抗氧化 ； 類黃酮

並列摘要

The goal of our research is to conduct bioactive compounds with tyrosinase inhibitory and antioxidative activities from the aerial part of Phyla nodiflora. The methanolic extracts of Phyla nodiflora showed potential total phenolic contents, tyrosinase inhibitory and free radical scavenging effect. In our continuous research, five compounds including eupafolin (1), hispidulin (2), larycitrin (3), β-sitosterol (4) and stigmasterol (5) were isolated. In antityrosinase assay, both eupafolin (1) and hispidulin (2) had good activity. Eupafolin (1) showed stronger activity (IC50 = 56.0 μM). In kinetic experiment, we found that eupafolin (1) showed competitive inhibition mode with tyrosinase. In radical scavenging assays, hispidulin (2) had good effect on both 1,1-diphenyl-2-picryhydrazyl (DPPH) and 2,2'-azinobis-3-ethylbenzo-
thiazoline-6-sulfonic acid (ABTS) radicals while eupafolin (1) had very good scavenging effect on DPPH, ABTS and superoxide anion radicals. Furthermore, we realized that eupafolin (1) inhibits xanthine oxidase with a mixed-type inhibition mode.

並列關鍵字

Phyla nodiflora ； tyrosinase ； antioxidant ； flavonoids

參考文獻

1. Huang T. C.; Keng H. Verbenaceae. Flora of Taiwan. 2nd ed. Editorial committee of the Flora of Taiwan, 1996, 694.

2. 鄭漢臣，藥用植物學，文光圖書有限公司，2004：254

3. 邱年永，原色台灣藥用植物圖鑑，台北南天書局，1998：186

4. Lejian Z. Use of extract of lippia nudiflora (l.) l.c.rich or lippia nodiflora rich. var. sarmentosa schou. in preparing medicinal preparation for treating hepatitis. Faming Zhuanli Shenqing Gongkai Shuomingshu. 2008, 19, 1203.

5. Siddiqui B. S.; Fayaz A.; Fouzia S.; Sabira B. Chemical constituents from the aerial parts of Lippia nodiflora Linn. Pharmacologyonline. 2007, 30(12), 1507.