Characterization of 2,4-Diamino-6-oxo-1,6-dihydropyrimidin-5-yl Ureido Based Inhibitors of Trypanosoma brucei FolD and Testing for Antiparasitic Activity

Abstract

The bifunctional enzyme N5,N10-methylenetetrahydrofolate dehydrogenase/cyclo hydrolase (FolD) is essential for growth in Trypanosomatidae. We sought to develop inhibitors of Trypanosoma brucei FolD (TbFolD) as potential antiparasitic agents. Compound 2 was synthesized, and the molecular structure was unequivocally assigned through X-ray crystallography of the intermediate compound 3. Compound 2 showed an IC50 of 2.2 μM, against TbFolD and displayed antiparasitic activity against T. brucei (IC50 49 μM). Using compound 2, we were able to obtain the first X-ray structure of TbFolD in the presence of NADP+ and the inhibitor, which then guided the rational design of a new series of potent TbFolD inhibitors.

Folates in Trypanosoma brucei: Achievements and Opportunities

“…In the first step (dehydrogenase, DH, EC 1.5.1.5) a NADP + ‐dependent oxidation takes place, then N 5 , N 10 ‐CH + ‐THF is hydrolyzed by an activated water molecule thanks to cyclohydrolase activity (CH, EC 3.5.4.9). The enzyme has been described as essential for Pseudomonas aeruginosa , L. major , and we recently assessed the T. brucei ortholog as a potential antiparasitic target . We have described a series of compounds derived from compound 41 ( K i 1.1 μ m ) in which we studied the effect of substitution of the amino acid tail (Figure ).…”

“…The enzymeh as been described as essential for Pseudomonas aeruginosa, [35] L. major, [34b] and we recently assessedt he T. brucei ortholog as ap otential antiparasitic target. [36] We have describedas eries of compounds derived from compound 41 (K i 1.1 mm)i nw hichw es tudied the effect of substitution of the amino acid tail (Figure 8). Compound 41 (EC 50 49 mm)s howed betteri nv itro selectivity than compound 42 (EC 50 53 mm), ak nown inhibitor of DHCH, [37] and allowed us to solve the structure of the ternary crystal 41-NADP + -TbDHCH.…”

An assessment of three human methylenetetrahydrofolate dehydrogenase/cyclohydrolase–ligand complexes following further refinement

“…The structure of the human DHCH domain has been reported in complex with three inhibitors (Schmidt et al, 2000), with the coordinates and structure factors available in the Protein Data Bank (PDB). The structures of homologues, together with information on inhibitors, have been exploited to inform early-stage drug discovery targeting primitive eukaryotic parasites and bacteria Eadsforth et al, 2015). During this assessment we noted in the publication (Schmidt et al, 2000) and in the database entries relating to the inhibitors that we sought to understand and/or address.…”

Estudos estruturais e funcionais da enzima N⁵, N¹⁰ - metilenotetrahidrofolato-desidrogenase-ciclohidrolase de <i>Xanthomonas albilineans</i> aplicados à descoberta de candidatos a inibidores para o tratamento da escaldadura das folhas

“…Eadsforth e colaboradores 87 demonstraram, através da síntese de análogos e avaliação da atividade inibitória contra a TbFolD, que o aumento da complementariedade estérica dos inibidores na região da cauda glutamilada aumenta a potência.…”

“…nitrogênio da adenina. [70][71][72][73][74][75][76][77][78][79][80][81][82][83][84][85][86][87][88] A interação com a nicotinamida do NADP + é mantida pela T279 na TbFolD, e pela T278 na…”