Synthesis, biological, and antitumor activity of a highly potent 6-substituted pyrrolo[2,3-d]pyrimidine thienoyl antifolate inhibitor with proton-coupled folate transporter and folate receptor selectivity over the reduced folate carrier that inhibits β-glycinamide ribonucleotide formyltransferase.

Abstract

2-Amino-4-oxo-6-substituted pyrrolo[2,3-d]pyrimidine antifolates with a thienoyl side chain (compounds 1-3, respectively) were synthesized for comparison with compound 4, the previous lead compound of this series. Conversion of hydroxyl acetylen-thiophene carboxylic esters to thiophenyl-α-bromomethylketones and condensation with 2,4-diamino-6-hydroxypyrimidine afforded the 6-substituted pyrrolo[2,3-d]pyrimidine compounds of type 18 and 19. Coupling with l-glutamate diethyl ester, followed by saponification, afforded 1-3. Compound 3 selectively inhibited the proliferation of cells expressing folate receptors (FRs) α or β, or the proton-coupled folate transporter (PCFT), including KB and IGROV1 human tumor cells, much more potently than 4. Compound 3 was more inhibitory than 4 toward β-glycinamide ribonucleotide formyltransferase (GARFTase). Both 3 and 4 depleted cellular ATP pools. In SCID mice with IGROV1 tumors, 3 was more efficacious than 4. Collectively, our results show potent antitumor activity for 3 in vitro and in vivo, associated with its selective membrane transport by FRs and PCFT over RFC and inhibition of GARFTase, clearly establishing the 3-atom bridge as superior to the 1-, 2-, and 4-atom bridge lengths for the activity of this series.

• Authors: Lei Wang, Sita Kugel Desmoulin, Christina Cherian, Lisa Polin, Kathryn White, Juiwanna Kushner, Andreas Fulterer, Min-Hwang Chang, Shermaine Mitchell-Ryan, Mark Stout, Michael F Romero, Zhanjun Hou, Larry H Matherly, Aleem Gangjee
• Journal: Journal of medicinal chemistry (J Med Chem) Vol. 54 Issue 20 Pg. 7150-64 (Oct 27 2011) ISSN: 1520-4804 [Electronic] United States
• PMID: 21879757 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Antineoplastic Agents
• Folate Receptor 1
• Folate Receptor 2
• Folic Acid Antagonists
• Glutamates
• N-((5-((2-amino-4-oxo-4,7-dihydro-3H-pyrrolo(2,3-d)pyrimidin-6-yl)propyl)thiophen-2-yl)carbonyl)glutamic acid
• Proton-Coupled Folate Transporter
• Pyrimidines
• Pyrimidinones
• Reduced Folate Carrier Protein
• Adenosine Triphosphate
• Phosphoribosylglycinamide Formyltransferase

Topics

• Adenosine Triphosphate (metabolism)
• Animals
• Antineoplastic Agents (chemical synthesis, chemistry, pharmacology)
• Cell Line, Tumor
• Drug Screening Assays, Antitumor
• Female
• Folate Receptor 1 (metabolism)
• Folate Receptor 2 (metabolism)
• Folic Acid Antagonists (chemical synthesis, chemistry, pharmacology)
• Glutamates (chemical synthesis, chemistry, pharmacology)
• Humans
• Mice
• Mice, SCID
• Neoplasm Transplantation
• Oocytes (drug effects, physiology)
• Patch-Clamp Techniques
• Phosphoribosylglycinamide Formyltransferase (antagonists & inhibitors)
• Proton-Coupled Folate Transporter (metabolism)
• Pyrimidines (chemical synthesis, chemistry, pharmacology)
• Pyrimidinones (chemical synthesis, chemistry, pharmacology)
• Reduced Folate Carrier Protein (metabolism)
• Stereoisomerism
• Structure-Activity Relationship
• Transplantation, Heterologous
• Xenopus