Background: The World Health Organization catalogues illnesses such as Leishmaniasis as neglected diseases, due to low investment in new drugs to fight them. The search of novel and non-side effects anti-parasitic compounds is one of the urgent needs for the Third World. The use of triazolopyrimidines and their metallic complexes has demonstrated hopeful results in this field.

Objective: This work studies the antiparasitic efficacy of a series of 5,7-dimethyl-1,2,4- triazolo[1,5-a]pyrimidine first row transition metal complexes against three leishmania spp. strains.

Methods: The in vitro antiproliferation of promastigote forms of different strains of leishmania spp. (L. infantum, L. braziliensis and L donovani) and the cytotoxicity in macrophage host cells are reported here. The antiparasitic assays have been complemented with enzymatic tests to elucidate the mechanisms of action. New crystal structure description, thermal analysis, magnetic susceptibility and magnetization experiments have also been carried out in order to present a whole characterization of the studied compounds and interesting physical properties besides the biological tests.

Results: The results of antiproliferation screening and cytotoxicity show great antiparasitic efficacy in the studied complexes. The superoxide dismutase enzymatic assays exhibit a different behaviour according to the thermochromic triazolopyrimidine form tested.

Conclusion: Antiproliferative assays and enzymatic tests corroborate the synergetic leishmanicidal effect present in coordination triazolopyrimidine complexes. The changes in coordination sphere derived from thermochromism affect the physical properties as well as the biological efficacy.

背景：世界卫生组织将诸如利什曼病等疾病归类为被忽视的疾病，原因是对新药的投入很少，以抗击这些疾病。寻找新颖且无副作用的抗寄生虫化合物是第三世界的迫切需求之一。三唑并嘧啶及其金属配合物的使用在该领域显示出希望的结果。

目的：这项工作研究了一系列5,7-二甲基-1,2,4-三唑并[1,5-a]嘧啶第一排过渡金属配合物对三种利什曼原虫的抗寄生虫功效。株。

方法：不同菌株利什曼原虫的前鞭毛体形式的体外抗增殖。（婴儿乳杆菌，巴西乳杆菌和多诺尼乳）和巨噬细胞宿主细胞的细胞毒性在这里有报道。抗寄生虫检测已辅以酶促检测，以阐明其作用机理。还进行了新的晶体结构描述，热分析，磁化率和磁化实验，以提供所研究化合物的整体表征以及除生物学测试之外的有趣物理性质。

结果：抗增殖筛选和细胞毒性的结果表明，在所研究的复合物中具有很好的抗寄生虫功效。根据所测试的热变色三唑并嘧啶形式，超氧化物歧化酶的酶促测定显示出不同的行为。

结论：抗增殖试验和酶促试验证实了配位三唑并嘧啶复合物中存在的协同利什曼杀菌作用。由热致变色引起的配位球的变化影响物理性质以及生物学功效。