Pure compound screening has previously identified the indolglyoxy lamidospermidine ascidian metabolites didemnidine A and B (2 and 3) to be weak growth inhibitors of Trypanosoma brucei rhodesiense (IC50 59 and 44 μM, respectively) and Plasmodium falciparum (K1 dual drug resistant strain) (IC50 41 and 15 μM, respectively), but lacking in selectivity (L6 rat myoblast, IC50 24 μM and 25 μM, respectively). To expand the structure–activity relationship of this compound class towards both parasites, we have prepared and biologically tested a library of analogues that includes indoleglyoxyl and indoleacetic “capping acids”, and polyamines including spermine (PA3-4-3) and extended analogues PA3-8-3 and PA3-12-3. 7-Methoxy substituted indoleglyoxylamides were typically found to exhibit the most potent antimalarial activity (IC50 10–92 nM) but with varying degrees of selectivity versus the L6 rat myoblast cell line. A 6-methoxyindolglyoxylamide analogue was the most potent growth inhibitor of T. brucei (IC50 0.18 μM) identified in the study: it, however, also exhibited poor selectivity (L6 IC50 6.0 μM). There was no apparent correlation between antimalarial and anti-T. brucei activity in the series. In vivo evaluation of one analogue against Plasmodium berghei was undertaken, demonstrating a modest 20.9% reduction in parasitaemia.
纯化合物筛选之前已确定,indolglyoxy lamidospermidine海鞘代谢物didemnidine A和B(2和3)对锥虫(Trypanosoma brucei rhodesiense)的生长抑制作用较弱(IC50分别为59和44 μM),以及对抗疟原虫(Plasmodium falciparum K1双重耐药株)(IC50分别为41和15 μM),但缺乏选择性(L6大鼠肌母细胞,IC50分别为24 μM和25 μM)。为了扩展这种化合物类别的结构-活性关系,针对这两种寄生虫,我们准备并进行了包括indoleglyoxyl和indoleacetic“封端酸”的类似物库,以及
多胺如
精胺(PA3-4-3)及其扩展的类似物PA3-8-3和PA3-12-3的
生物测试。7-甲氧基取代的indoleglyoxylamides通常表现出最强的抗疟活动(IC50 10–92 nM),但与L6大鼠肌母
细胞系相比,选择性程度各异。6-甲氧基indolglyoxylamide类似物是本研究中发现的对T. brucei的最强生长
抑制剂(IC50 0.18 μM);然而,它的选择性也较差(L6 IC50 6.0 μM)。在系列化合物中,抗疟活动与抗T. brucei活动之间没有明显相关性。对一种类似物进行抗Plasmodium berghei的体内评估,显示出寄生血症减少20.9%的适度效果。