Amides of substituted 3-(pteridin-6-yl)propanoic acids: synthesis, spectral characteristics, and cytotoxic activity

A heterocyclization reaction of 5,6-diamino-1-methyluracil and 2-oxopentanedioic acid was used in this study to synthesize 3-(1-methyl-2,4,7-trioxo-1,2,3,4,7,8-hexahydropteridin-6-yl)propanoic acid, intramolecular cyclization of which led to the formation of a tricyclic lactone, namely, 1-methyl-6,7-dihydro-2 H -pyrano[3,2 -g ]pteridine-2,4,8-(1 H ,3 H )-trione. Reactions of the latter with N- nucleophiles gave a series of amides – structural analogs of antifolates. The structure and identity of the synthesized compounds were confirmed by IR spectroscopy, 1 H and 13 C NMR spectroscopy, LC-MS analysis, and mass spectrometry. It was established that the synthesized compounds showed cytotoxic effects against human hepatocellular carcinoma (HepG2) cells and may be of interest for further studies of their antitumor activity against other cell lines.