Synthesis and biological activity of an acyclic analogue of 5,6,7,8-tetrahydrofolic acid, N-[4-[[3-(2,4-diamino-1,6-dihydro-6-oxo-5- pyrimidinyl)propyl]amino]-benzoyl]-L-glutamic acid

J Med Chem. 1990 Feb;33(2):561-7. doi: 10.1021/jm00164a014.


The synthesis and biological evaluation of N-[4-[[3-(2,4-diamino-1,6-dihydro-6-oxo-5-pyrimidinyl)propyl]amino]- benzoyl]-L-glutamic acid (1) (5-DACTHF, 543U76), an acyclic analogue of 5,6,7,8-tetrahydrofolic acid (THFA), are described. The key intermediate, hemiaminal 8, was prepared in four stages from 3-chloropropionaldehyde diethyl acetal. Reaction of 8 with dimethyl N-(4-aminobenzoyl)-L-glutamate gave the 2,4-bis(acetylamino) derivative 11, which was hydrolyzed with 1 N sodium hydroxide to give 1; the glycine analogue 16 was prepared in a similar manner. The N-methyl analogue 2 and N-formyl analogue 3 were prepared from 11 and 1, respectively. Compounds 1-3 inhibited growth of Detroit 98 and L cells in cell culture, with IC50s ranging from 2 to 0.018 microM. Cell culture toxicity reversal studies and enzyme inhibition tests showed that 1 was cytotoxic but not by the mechanism of the dihydrofolate reductase inhibitor aminopterin. Compound 1 and its polyglutamylated homologues inhibited glycinamide ribonucleotide transformylase (GAR-TFase) and aminoimidazole ribonucleotide transformylase (AICAR-TFase), the folate-dependent enzymes in de novo purine biosynthesis; and 1 was an effective substrate for mammalian folyl-polyglutamate synthetase. The compound inhibited (IC50 = 20 nM) the conversion of [14C]formate to [14C]-formylglycinamide ribonucleotide by MOLT-4 cells in culture. These data suggest that the site of action of 1 is inhibition of purine de novo biosynthesis. Moderate activity was observed against P388 leukemia in vivo.

MeSH terms

  • Acyltransferases / antagonists & inhibitors
  • Animals
  • Antimetabolites, Antineoplastic / chemical synthesis*
  • Antimetabolites, Antineoplastic / pharmacology
  • Cell Line
  • Chemical Phenomena
  • Chemistry
  • Folic Acid Antagonists / chemical synthesis*
  • Folic Acid Antagonists / pharmacology
  • Hydroxymethyl and Formyl Transferases*
  • Leukemia, Experimental / drug therapy
  • Mice
  • Peptide Synthases / metabolism
  • Phosphoribosylaminoimidazolecarboxamide Formyltransferase
  • Phosphoribosylglycinamide Formyltransferase
  • Purines / metabolism
  • Structure-Activity Relationship
  • Tetrahydrofolates / chemical synthesis*
  • Tetrahydrofolates / pharmacology


  • Antimetabolites, Antineoplastic
  • Folic Acid Antagonists
  • Purines
  • Tetrahydrofolates
  • N-(4-((3-(2,4-diamino-1,6-dihydro-6-oxo-5-pyrimidinyl)propyl)amino)benzoyl)glutamic acid
  • Hydroxymethyl and Formyl Transferases
  • Phosphoribosylglycinamide Formyltransferase
  • Phosphoribosylaminoimidazolecarboxamide Formyltransferase
  • Acyltransferases
  • Peptide Synthases
  • folylpolyglutamate synthetase