J Med Chem. 2007 Feb 2; [Epub ahead of print]
Highly Efficient Ligands for Dihydrofolate Reductase from Cryptosporidium hominis and Toxoplasma gondii Inspired by Structural Analysis.
Pelphrey PM, Popov VM, Joska TM, Beierlein JM, Bolstad ES, Fillingham YA, Wright DL, Anderson AC.
Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755, Department of Biochemistry, Dartmouth Medical School, Hanover, New Hampshire 03755, Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, and Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut 06269.
The search for effective therapeutics for cryptosporidiosis and toxoplasmosis has led to the discovery of novel inhibitors of dihydrofolate reductase (DHFR) that possess high ligand efficiency: compounds with high potency and low molecular weight. Detailed analysis of the crystal structure of dihydrofolate reductase-thymidylate synthase from Cryptosporidium hominis and a homology model of DHFR from Toxoplasma gondii inspired the synthesis of a new series of compounds with a propargyl-based linker between a substituted 2,4-diaminopyrimidine and a trimethoxyphenyl ring. An enantiomerically pure compound in this series exhibits IC50 values of 38 and 1 nM against C. hominis and T. gondii DHFR, respectively. Improvements of 368-fold or 5714-fold (C. hominis and T. gondii) relative to trimethoprim were generated by synthesizing just 14 new analogues and by adding only a total of 52 Da to the mass of the parent compound, creating an efficient ligand as an excellent candidate for further study.
PMID: 17269758 [PubMed - as supplied by publisher]