Sesquiterpene lactones (STLs) are natural products that have potent antitrypanosomal activity in vitro and, in the case of cynaropicrin, also reduce parasitemia in the murine model of trypanosomiasis. To explore their structure-antitrypanosomal activity relationships, a set of 34 natural and semi-synthetic STLs and amino-STLs was tested in vitro against T. b. rhodesiense (which causes East African sleeping sickness) and mammalian cancer cells (rat bone myoblast L6 cells). It was found that the α-methylene-γ-lactone moiety is necessary for both antitrypanosomal effects and cytotoxicity. Antitrypanosomal selectivity is facilitated by 2-(hydroxymethyl)acrylate or 3,4-dihydroxy-2-methylenebutylate side chains, and by the presence of cyclopentenone rings. Semi-synthetic STL amines with morpholino and dimethylamino groups showed improved in vitro activity over the native STLs. The dimethylamino derivative of cynaropicrin was prepared and tested orally in the T. b. rhodesiense acute mouse model, where it showed reduced toxicity over cynaropicrin, but also lost antitrypanosomal activity.
倍半萜内酯(STL)是一种天然产品,在体外具有强大的抗锥虫活性,在犬鞭毛虫素的情况下,还能降低锥虫病小鼠模型中的寄生虫血症。为了探索它们的结构与抗锥虫活性之间的关系,我们对 34 种天然和半合成的 STL 和
氨基 STL 进行了体外测试,以检测它们对罗得西亚锥虫(导致东非昏睡病)和哺乳动物癌细胞(大鼠骨肌母细胞 L6 细胞)的抗锥虫活性。结果发现,α-亚甲基-γ-内酯分子对于抗盘虫作用和细胞毒性都是必需的。2-(羟甲基)
丙烯酸酯或 3,4-二羟基-2-亚甲基
丁酸侧链以及
环戊烯酮环的存在有助于提高抗盘虫选择性。与原生 STL 相比,带有吗啉基和二甲基
氨基基团的半合成 STL
氨基化合物显示出更强的体外活性。我们制备了卡诺匹克林的二甲基
氨基衍
生物,并在罗得西亚锥虫病急性小鼠模型中进行了口服测试,结果表明该衍
生物的毒性比卡诺匹克林低,但也失去了抗锥虫活性。