Laboratoire de Pharmacognosie, Drug Research Center (CIRM), Université de Liège, Liège, Belgium.
Phytochemistry. 2013 Mar;87:157-63. doi: 10.1016/j.phytochem.2012.11.002. Epub 2012 Dec 6.
Strychnos nux-vomica L. (Loganiaceae) is famous for its monomeric alkaloid content, such as strychnine, a convulsant poison. The stem bark of the tree is traditionally used to treat intermittent fever in South East Asia. In various studies, it appeared that dimeric indolo-monoterpenic alkaloids possess a promising activity on Plasmodium falciparum. Three bisindolomonoterpenic alkaloids together with strychnochrysine, previously identified in the root bark of S. nux-vomica, were isolated from the stem bark. The structures of these compounds were established using NMR spectroscopy and mass spectrometry. Stereochemistry of the compounds was confirmed by molecular modelling. This then allowed the structural determination of strychnoflavine, a coloured bisindole alkaloid previously isolated from the root bark of the tree. Moreover, the conformational inversion in alkaloids possessing an ether bond in the strychnane moiety could be easily predicted by specific δ (13)C NMR values. These longicaudatine-type alkaloids were found to display in vitro antiplasmodial activity against a chloroquine resistant strain and a chloroquine sensitive strain. The most interesting was strychnochrysine showing an IC(50) value at around 10 μM.
马钱科植物马钱 Strychnos nux-vomica L. 以其单体生物碱含量而闻名，如马钱子碱，一种惊厥性毒物。该树的茎皮传统上用于治疗东南亚的间歇性发热。在各种研究中，似乎二聚吲哚单萜生物碱对恶性疟原虫具有有前途的活性。从茎皮中分离出了三种双吲哚单萜生物碱以及先前在马钱子根皮中鉴定出的斯特雷乔辛。这些化合物的结构是通过 NMR 光谱和质谱确定的。通过分子建模证实了化合物的立体化学。这使得先前从该树的根皮中分离出的有色双吲哚生物碱马钱黄素的结构得以确定。此外，在具有斯特雷奇烷部分中醚键的生物碱中，构象反转可以通过特定的 δ（13）C NMR 值轻松预测。这些长尾碱型生物碱被发现对氯喹耐药株和氯喹敏感株具有体外抗疟活性。最有趣的是斯特雷乔辛，其 IC（50）值约为 10 μM。
