3GHC

Design, Synthesis, and X-ray Crystal Structure of Classical and Nonclassical 2-amino-4-oxo-5-substituted-6-thieno[2,3-d]pyrimidines as dual thymidylate synthase and dihydrofolate reductase inhibitors and as potential antitumor agenst

Summary for 3GHC

• Entry DOI: 10.2210/pdb3ghc/pdb
• Related: 3f84 3GHV 3GHW
• Descriptor: Dihydrofolate reductase, N-({4-[(2-amino-6-ethyl-4-oxo-3,4-dihydrothieno[2,3-d]pyrimidin-5-yl)sulfanyl]phenyl}carbonyl)-L-glutamic acid, NADPH DIHYDRO-NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE, ... (5 entities in total)
• Functional Keywords: protein inhibitor complex folate analogues, nadp, one-carbon metabolism, oxidoreductase
• Biological source: Homo sapiens (human)
• Total number of polymer chains: 1
• Total formula weight: 22791.58

Authors

Cody, V. (deposition date: 2009-03-03, release date: 2009-09-22, Last modification date: 2023-09-06)

Primary citation

Gangjee, A.,Li, W.,Kisliuk, R.L.,Cody, V.,Pace, J.,Piraino, J.,Makin, J.
Design, synthesis, and X-ray crystal structure of classical and nonclassical 2-amino-4-oxo-5-substituted-6-ethylthieno[2,3-d]pyrimidines as dual thymidylate synthase and dihydrofolate reductase inhibitors and as potential antitumor agents
J.Med.Chem., 52:4892-4902, 2009

PubMed Abstract: N-{4-[(2-Amino-6-ethyl-4-oxo-3,4-dihydrothieno[2,3-d]pyrimidin-5-yl)thio]benzoyl}-L-glutamic acid 2 and 13 nonclassical analogues 2a-2m were synthesized as potential dual thymidylate synthase (TS) and dihydrofolate reductase (DHFR) inhibitors and as antitumor agents. The key intermediate in the synthesis was 2-amino-6-ethyl-5-iodothieno[2,3-d]pyrimidin-4(3H)-one, 7, to which various arylthiols were attached at the 5-position. Coupling 8 with L-glutamic acid diethyl ester and saponification afforded 2. X-ray crystal structures of 2 and 1 (the 6-methyl analogue of 2), DHFR, and NADPH showed for the first time that the thieno[2,3-d]pyrimidine ring binds in a "folate" mode. Compound 2 was an excellent dual inhibitor of human TS (IC50 = 54 nM) and human DHFR (IC50 = 19 nM) and afforded nanomolar GI50 values against tumor cells in culture. The 6-ethyl substitution in 2 increases both the potency (by 2-3 orders of magnitude) as well as the spectrum of tumor inhibition in vitro compared to the 6-methyl analogue 1. Some of the nonclassical analogues were potent and selective inhibitors of DHFR from Toxoplasma gondii.

PubMed: 19719239
DOI: 10.1021/jm900490a

Experimental method

X-RAY DIFFRACTION (1.3 Å)