Dual inhibitors of thymidylate synthase and dihydrofolate reductase as antitumor agents: design, synthesis, and biological evaluation of classical and nonclassical pyrrolo[2,3-d]pyrimidine antifolates(1)

J Med Chem. 2006 Feb 9;49(3):1055-65. doi: 10.1021/jm058276a.

Abstract

We designed and synthesized a classical analogue N-[4-[(2-amino-6-ethyl-3,4-dihydro-4-oxo-7H-pyrrolo[2,3-d]pyrimidin-5-yl)thio]benzoyl]-L-glutamic acid (4) and thirteen nonclassical analogues 5-17 as potential dual thymidylate synthase (TS) and dihydrofolate reductase (DHFR) inhibitors and as antitumor agents. The key intermediate in their synthesis was 2-amino-6-ethyl-3,4-dihydro-4-oxo-7H-pyrrolo[2,3-d]pyrimidine, 22, to which various aryl thiols were conveniently attached at the 5-position via an oxidative addition reaction using iodine. For the classical analogue 4, the ester obtained from the reaction was deprotected and coupled with diethyl L-glutamate followed by saponification. Compound 4 was a potent dual inhibitor of human TS (IC(50) = 90 nM) and human DHFR (IC(50) = 420 nM). Compound 4 was not a substrate for human FPGS. Metabolite protection studies established TS as its principal target. Most of the nonclassical analogues were only inhibitors of human TS with IC(50) values of 0.23-26 microM.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Antineoplastic Agents / chemical synthesis*
  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / pharmacology
  • Binding Sites
  • Cell Line, Tumor
  • Drug Screening Assays, Antitumor
  • Escherichia coli / enzymology
  • Folic Acid Antagonists / chemical synthesis*
  • Folic Acid Antagonists / chemistry
  • Folic Acid Antagonists / pharmacology
  • Glutamates / chemical synthesis*
  • Glutamates / chemistry
  • Glutamates / pharmacology
  • Humans
  • Models, Molecular
  • Pyrimidines / chemical synthesis*
  • Pyrimidines / chemistry
  • Pyrimidines / pharmacology
  • Pyrimidinones / chemical synthesis*
  • Pyrimidinones / chemistry
  • Pyrimidinones / pharmacology
  • Pyrroles / chemical synthesis*
  • Pyrroles / chemistry
  • Pyrroles / pharmacology
  • Structure-Activity Relationship
  • Tetrahydrofolate Dehydrogenase / chemistry*
  • Thermodynamics
  • Thymidylate Synthase / antagonists & inhibitors*
  • Thymidylate Synthase / chemistry*

Substances

  • Antineoplastic Agents
  • Folic Acid Antagonists
  • Glutamates
  • N-(4-((2-amino-6-ethyl-3,4-dihydro-4-oxo-7H-pyrrolo(2,3-d)pyrimidin-5-yl)thio)benzoyl)glutamic acid
  • Pyrimidines
  • Pyrimidinones
  • Pyrroles
  • Tetrahydrofolate Dehydrogenase
  • Thymidylate Synthase