Antimalarial activity of prodrugs of N-branched acyclic nucleoside phosphonate inhibitors of 6-oxopurine phosphoribosyltransferases.
Acyclic nucleoside phosphonates (ANPs) that contain a 6-oxopurine base are good inhibitors of the human and Plasmodium falciparum 6-oxopurine phosphoribosyltransferases (PRTs), key enzymes of the purine salvage pathway. Chemical modifications, based on the crystal structures of several inhibitors in complex with the human PRTase, led to the design of a new class of inhibitors--the aza-ANPs. Because of the negative charges of the phosphonic acid moiety, their ability to cross cell membranes is, however, limited. Thus, phosphoramidate prodrugs of the aza-ANPs were prepared to improve permeability. These prodrugs arrest parasitemia with IC50 values in the micromolar range against Plasmodium falciparum-infected erythrocyte cultures (both chloroquine-sensitive and chloroquine-resistant Pf strains). The prodrugs exhibit low cytotoxicity in several human cell lines. Thus, they fulfill two essential criteria to qualify them as promising antimalarial drug leads.
Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i. Flemingovo nám. 2, CZ-166 10 Prague 6, Czech Republic. Electronic address: lasice@uochb.cas.cz.
Dana
D
Hocková
Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i. Flemingovo nám. 2, CZ-166 10 Prague 6, Czech Republic.
Zlatko
Z
Janeba
Rega Institute for Medical Research, KU Leuven-University of Leuven, Minderbroedersstraat 10, B-3000 Leuven, Belgium.
Lieve
L
Naesens
Department of Drug Evaluation, Australian Army Malaria Institute, Enoggera, Brisbane, QLD 4051, Australia.
Michael D
MD
Edstein
Department of Drug Evaluation, Australian Army Malaria Institute, Enoggera, Brisbane, QLD 4051, Australia.
Marina
M
Chavchich
The School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane 4072, QLD, Australia.
Dianne T
DT
Keough
The School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane 4072, QLD, Australia. Electronic address: luke.guddat@uq.edu.au.
Luke W
LW
Guddat
D000962:Antimalarials / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000378:metabolism*; D006801:Humans; D007041:Hypoxanthine Phosphoribosyltransferase / Q000037:antagonists & inhibitors*; D008288:Malaria / Q000188:drug therapy*; D008958:Models, Molecular; D009711:Nucleotides / Q000378:metabolism*; D063065:Organophosphonates / Q000737:chemistry*; D011355:Prodrugs
D000962:Antimalarials; D004791:Enzyme Inhibitors; D009711:Nucleotides; D063065:Organophosphonates; D011355:Prodrugs; D007041:Hypoxanthine Phosphoribosyltransferase
ANP; Enzyme inhibitors; HG(X)PRT; Malaria; Nucleotide analogues