ABSTRACT
Aromatic dicationic molecules possess impressive activity against a broad spectrum of microbial pathogens, including
Pneumocystis carinii
,
Cryptosporidium parvum
, and
Candida albicans
. In this work, 58 aromatic cations were examined for inhibitory activity against axenic amastigote-like
Leishmania donovani
parasites. In general, the most potent of the compounds were substituted diphenyl furan and thiophene dications. 2,5-Bis-(4-amidinophenyl)thiophene was the most active compound. This agent displayed a 50% inhibitory concentration (IC
50
) of 0.42 ± 0.08 μM against
L. donovani
and an in vitro antileishmanial potency 6.2-fold greater than that of the clinical antileishmanial dication pentamidine and was 155-fold more toxic to the parasites than to a mouse macrophage cell line. 2,4-Bis-(4-amidinopheny)furan was twice as active as pentamidine (IC
50
, 1.30 ± 0.21 μM), while 2,5-bis-(4-amidinopheny)furan and pentamidine were essentially equipotent in our in vitro antileishmanial assay. Carbazoles, dibenzofurans, dibenzothiophenes, and benzimidazoles containing amidine or substituted amidine groups were generally less active than the diphenyl furans and thiophenes. In all cases, aromatic dications possessing strong antileishmanial activity were severalfold more toxic to the parasites than to a cultured mouse macrophage cell line. These structure-activity relationships demonstrate the potent antileishmanial activity of several aromatic dications and provide valuable information for the future design and synthesis of more potent antiparasitic agents.
摘要
芳香族二阳离子分子对多种微生物病原体具有令人印象深刻的活性,包括
卡氏肺囊虫
,
副猪隐孢子虫
和
白色念珠菌
.在这项工作中,研究了 58 种芳香族阳离子对轴突吸虫类
利什曼原虫
寄生虫的抑制活性。一般来说,最有效的化合物是取代的二苯基呋喃和噻吩二阳离子。2,5-双(4-脒基苯基)噻吩是活性最强的化合物。这种药剂显示出 50%的抑制浓度(IC
50
)为 0.42 ± 0.08 μM
多诺万
体外抗利什曼药效是临床抗利什曼药喷他脒的 6.2 倍,对寄生虫的毒性是小鼠巨噬细胞系的 155 倍。2,4-双(4-脒苯基)呋喃的活性是喷他脒的两倍(IC
50
1.30 ± 0.21 μM),而在体外抗利什曼病试验中,2,5-双(4-脒苯基)呋喃和喷他脒的活性基本相当。含有脒基或取代脒基的咔唑、二苯并呋喃、二苯并噻吩和苯并咪唑的活性通常低于二苯基呋喃和噻吩。在所有情况下,具有较强抗利什曼活性的芳香族二元酸盐对寄生虫的毒性比对培养的小鼠巨噬细胞系的毒性高出数倍。这些结构-活性关系证明了几种芳香族配位化合物具有很强的抗利什曼病活性,并为今后设计和合成更强的抗寄生虫药物提供了宝贵的信息。