Department of Chemistry and Centre for Pharmacy, University of Bergen, Allégt, Bergen, Norway.
Pharm Biol. 2013 Aug;51(8):981-6. doi: 10.3109/13880209.2013.773520. Epub 2013 Jun 4.
The European white-berry mistletoe [Viscum album L. (Loranthaceae)] is among the oldest known medicinal plants. At present the most important application of mistletoe extracts is in the treatment of cancer. However, natural products specific to mistletoe have rarely been encountered in the current literature.
To discover novel natural products specific to European mistletoe.
European mistletoe was extracted with methanol, purified to partition against diethyl ether and further purified with XAD-7 column chromatography. Pure compounds were separated by Sephadex column chromatography and preparative HPLC. The structures of the novel compounds were established using a combination of several 2D NMR spectroscopic techniques and mass spectrometry.
A new type of natural product derived from the methyl ester of γ-hydroxybutyric acid (GHB) coupled to hydroxybenzoic acids, namely 3-(3'-carbomethoxypropyl) gallic acid and 3-(3'-carbomethoxypropyl)-7→3″-protocatechoyl galloate were characterized from European white-berry mistletoe. Condensation of the 3-hydroxyl of gallic acid with the 4-hydroxyl of GHB significantly reduced the radical scavenging properties of the former compound.
The characterized compounds define a novel group of natural products that may be of particular interest because it appears that the two new compounds are not closely related to any known natural product.
欧洲白浆果槲寄生[Viscum album L.（桑寄生科）]是最古老的药用植物之一。目前，槲寄生提取物最重要的应用是治疗癌症。然而，在当前的文献中很少遇到槲寄生特有的天然产物。
发现欧洲槲寄生特有的新型天然产物。
用甲醇提取欧洲槲寄生，用二乙醚进行分配纯化，并用 XAD-7 柱色谱进一步纯化。通过葡聚糖凝胶柱色谱和制备 HPLC 分离纯化合物。利用多种二维 NMR 波谱技术和质谱联用，确定了新型化合物的结构。
从欧洲白浆果槲寄生中鉴定出一种新型天然产物，它是γ-羟基丁酸（GHB）甲酯与羟基苯甲酸的缩合物，即 3-(3′- 羧甲基丙基）没食子酸和 3-(3′- 羧甲基丙基）-7→3″-原儿茶酰基没食子酸酯。没食子酸的 3- 羟基与 GHB 的 4- 羟基缩合显著降低了前一种化合物的自由基清除能力。
所鉴定的化合物定义了一类新型天然产物，这些天然产物可能特别有趣，因为这两种新化合物似乎与任何已知的天然产物都没有密切关系。
