Tasdemir Deniz, Güner Nadide Deniz, Perozzo Remo, Brun Reto, Dönmez Ali A, Calis Ihsan, Rüedi Peter
Institute of Organic Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland.
Phytochemistry. 2005 Feb;66(3):355-62. doi: 10.1016/j.phytochem.2004.11.013.
The ethanolic root extract of Scrophularia lepidota, an endemic plant of the Turkish flora, has been investigated for its anti-protozoal and inhibitory effect towards plasmodial enoyl-ACP reductase (FabI), a key enzyme of fatty acid biosynthesis in Plasmodium falciparum. Chromatographic separation of the extract yielded 10 iridoids (1-10), two of which are new, and a known phenylethanoid glycoside (11). The structures of the new compounds were determined as 3,4-dihydro-methylcatalpol (8) and 6-O-[4''-O-trans-(3,4-dimethoxycinnamoyl)-alpha-L-rhamnopyranosyl]aucubin (scrolepidoside, 9) by spectroscopic means. The remaining metabolites were characterized as catalpol (1), 6-O-methylcatalpol (2), aucubin (3), 6-O-alpha-L-rhamnopyranosyl-aucubin (sinuatol, 4), 6-O-beta-D-xylopyranosylaucubin (5), ajugol (6), ajugoside (7), an iridoid-related aglycone (10) and angoroside C (11). Nine isolates were active against Leishmania donovani, with the new compound 9 being most potent (IC50 6.1 microg/ml). Except for 4, all pure compounds revealed some trypanocidal potential against Trypanosoma brucei rhodesiense (IC50 values 29.3-73.0 microg/ml). Only compound 10 showed moderate anti-plasmodial (IC50 40.6 microg/ml) and FabI enzyme inhibitory activity (IC50 100 microg/ml). 10 is the second natural product inhibiting the fatty acid biosynthesis of Plasmodium falciparum.
玄参科植物鳞叶玄参（Scrophularia lepidota）是土耳其植物区系中的一种特有植物，其乙醇根提取物已针对其抗原生动物作用以及对恶性疟原虫脂肪酸生物合成的关键酶——烯酰-ACP还原酶（FabI）的抑制作用进行了研究。提取物经色谱分离得到10种环烯醚萜（1-10），其中两种为新化合物，以及一种已知的苯乙醇苷（11）。通过光谱手段将新化合物的结构确定为3,4-二氢甲基梓醇（8）和6-O-[4''-O-反式-(3,4-二甲氧基肉桂酰基)-α-L-鼠李吡喃糖基]桃叶珊瑚苷（鳞叶玄参苷，9）。其余代谢产物鉴定为梓醇（1）、6-O-甲基梓醇（2）、桃叶珊瑚苷（3）、6-O-α-L-鼠李吡喃糖基-桃叶珊瑚苷（辛那托醇，4）、6-O-β-D-木糖吡喃糖基桃叶珊瑚苷（5）、筋骨草醇（6）、筋骨草苷（7）、一种与环烯醚萜相关的苷元（10）和角蒿苷C（11）。9种分离物对杜氏利什曼原虫有活性，新化合物9活性最强（IC50为6.1μg/ml）。除4外，所有纯化合物对罗德西亚布氏锥虫均显示出一定的杀锥虫潜力（IC50值为29.3-73.0μg/ml）。只有化合物10表现出中等的抗疟活性（IC50为40.6μg/ml）和FabI酶抑制活性（IC50为100μg/ml）。10是第二种抑制恶性疟原虫脂肪酸生物合成的天然产物。
