Highly efficient ligands for dihydrofolate reductase from Cryptosporidium hominis and Toxoplasma gondii inspired by structural analysis.
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.
Pelphrey
Phillip M
PM
Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755, USA.
Popov
Veljko M
VM
Joska
Tammy M
TM
Beierlein
Jennifer M
JM
Bolstad
Erin S D
ES
Fillingham
Yale A
YA
Wright
Dennis L
DL
Anderson
Amy C
AC
D000480:Alkynes / Q000138:chemical synthesis / Q000737:chemistry; D000595:Amino Acid Sequence; D000818:Animals; D000981:Antiprotozoal Agents / Q000138:chemical synthesis* / Q000737:chemistry; D001555:Benzene Derivatives / Q000138:chemical synthesis / Q000737:chemistry; D003458:Cryptosporidium / Q000201:enzymology*; D005493:Folic Acid Antagonists / Q000138:chemical synthesis* / Q000737:chemistry; D008024:Ligands; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D023303:Oxazolidinones / Q000138:chemical synthesis* / Q000737:chemistry; D011743:Pyrimidines / Q000138:chemical synthesis* / Q000737:chemistry; D017386:Sequence Homology, Amino Acid; D013237:Stereoisomerism; D013762:Tetrahydrofolate Dehydrogenase / Q000737:chemistry*; D014122:Toxoplasma / Q000201:enzymology*
D000480:Alkynes; D000981:Antiprotozoal Agents; D001555:Benzene Derivatives; D005493:Folic Acid Antagonists; D008024:Ligands; D023303:Oxazolidinones; D011743:Pyrimidines; D013762:Tetrahydrofolate Dehydrogenase