Deoxyuridine triphosphate nucleotidohydrolase as a potential antiparasitic drug target.

This paper describes a structure−activity study to identify novel, small-molecule inhibitors of the enzyme deoxyuridine 5‘-triphosphate nucleotidohydrolase (dUTPase) from parasitic protozoa. The successful synthesis of a variety of analogues of dUMP is described in which the substituents are introduced at the 3‘- and 5‘-positions, together with variation in the heteroatom at the 5‘-position. The compounds were assayed against recombinant Plasmodium falciparum and Leishmania major enzymes and the human enzyme to give a measure of selectivity. The compounds were also tested in vitro against the intact parasites P. falciparum and L. donovani. A number of potent and selective inhibitors of the P. falciparum dUTPase that show drug-like properties and represent good leads for future development were identified. The best inhibitors included the compounds 5‘-tritylamino-2‘,5‘-dideoxyuridine (2j) (Ki = 0.2 μM) and 5‘-O-triphenylsilyl-2‘,3‘-didehydro-2‘,3‘-dideoxyuridine (5h) (Ki = 1.3 μM), with selectivity greater...