Synthesis and biological activity of 6-substituted pyrrolo[2,3-d]pyrimidine thienoyl regioisomers as inhibitors of de novo purine biosynthesis with selectivity for cellular uptake by high affinity folate receptors and the proton-coupled folate transporter over the reduced folate carrier

J Med Chem. 2012 Feb 23;55(4):1758-70. doi: 10.1021/jm201688n. Epub 2012 Feb 3.

Abstract

We previously reported the selective transport of classical 2-amino-4-oxo-6-substituted pyrrolo[2,3-d]pyrimidines with a thienoyl-for-benzoyl-substituted side chain and a three- (3a) and four-carbon (3b) bridge. Compound 3a was more potent than 3b against tumor cells. While 3b was completely selective for transport by folate receptors (FRs) and the proton-coupled folate transporter (PCFT) over the reduced folate carrier (RFC), 3a was not. To determine if decreasing the distance between the bicyclic scaffold and l-glutamate in 3b would preserve transport selectivity and potency against human tumor cells, 3b regioisomers with [1,3] (7 and 8) and [1,2] (4, 5, and 6) substitutions on the thienoyl ring and with acetylenic insertions in the four-atom bridge were synthesized and evaluated. Compounds 7 and 8 were potent nanomolar inhibitors of KB and IGROV1 human tumor cells with complete selectivity for FRα and PCFT over RFC.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkynes / chemistry
  • Animals
  • Antineoplastic Agents / chemical synthesis*
  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / pharmacology
  • CHO Cells
  • Cell Line, Tumor
  • Cricetinae
  • Cricetulus
  • Drug Screening Assays, Antitumor
  • Folate Receptor 1 / metabolism*
  • Humans
  • Proton-Coupled Folate Transporter / metabolism*
  • Purines / antagonists & inhibitors*
  • Purines / biosynthesis
  • Pyrimidines / chemical synthesis*
  • Pyrimidines / chemistry
  • Pyrimidines / pharmacology
  • Pyrroles / chemical synthesis*
  • Pyrroles / chemistry
  • Pyrroles / pharmacology
  • Reduced Folate Carrier Protein / metabolism*
  • Stereoisomerism
  • Structure-Activity Relationship
  • Thiophenes / chemical synthesis*
  • Thiophenes / chemistry
  • Thiophenes / pharmacology

Substances

  • Alkynes
  • Antineoplastic Agents
  • Folate Receptor 1
  • Proton-Coupled Folate Transporter
  • Purines
  • Pyrimidines
  • Pyrroles
  • Reduced Folate Carrier Protein
  • Thiophenes
  • purine