Irreversible Inhibition of Epidermal Growth Factor Receptor Activity by 3-Aminopropanamides

Abstract

Irreversible epidermal growth factor receptor (EGFR) inhibitors contain a reactive warhead which covalently interacts with a conserved cysteine residue in the kinase domain. The acrylamide fragment, a commonly employed warhead, effectively alkylates Cys797 of EGFR, but its reactivity can cause rapid metabolic deactivation or nonspecific reactions with offtargets. We describe here a new series of irreversible inhibitors containing a 3-aminopropanamide linked in position 6 to 4-anilinoquinazoline or 4-anilinoquinoline-3-carbonitrile driving portions. Some of these compounds proved to be as efficient as their acrylamide analogues in inhibiting EGFR-TK (TK = tyrosine kinase) autophosphorylation in A549 lung cancer cells. Moreover, several 3-aminopropanamides suppressed proliferation of gefitinib-resistant H1975 cells, harboring the T790M mutation in EGFR, at significantly lower concentrations than did gefitinib. A prototypical compound, N-(4-(3-bromoanilino)quinazolin-6-yl)-3-(dimethylamino)propanamide (5), did not show covalent binding to cell-free EGFR-TK in a fluorescence assay, while it underwent selective activation in the intracellular environment, releasing an acrylamide derivative which can react with thiol groups.

Heat Shock Protein 70 Inhibitors. 2. 2,5′-Thiodipyrimidines, 5-(Phenylthio)pyrimidines, 2-(Pyridin-3-ylthio)pyrimidines, and 3-(Phenylthio)pyridines as Reversible Binders to an Allosteric Site on Heat Shock Protein 70

“…Positioning the amine one carbon away, such as in 9 (R = 2-(dimethylamino)ethyl, Table 1), resulted in activity comparable to that of 7f in the growth inhibition and caspase-3,7 activation assays. In this case, 9 has the potential to undergo bioconversion in cells via β-elimination to the corresponding alkene, 31 and therefore, in addition to possible interactions described above, it may also interact with Cys267 covalently.…”

Optimization of Substituted 6-Salicyl-4-Anilinoquinazoline Derivatives as Dual EGFR/HER2 Tyrosine Kinase Inhibitors

“…Much of structural alterations of these compounds presented mostly exist at the 4-, 6-, and 7-positons of the basic quinazoline scaffold. Accordingly, a huge volume of researches on the synthesis, structure-activity relationships, and antiproliferative activities of the quinazoline-containing derivatives have been reported over the past ten years [18]–[21]. To our knowledge, the nitrogen at position 3 is important to EGFR inhibitory potency, but the nitrogen at position 1 is an even more important contributor [18].…”

Reversible Michael Additions: Covalent Inhibitors and Prodrugs

“…Two major strategies can be defined to develop safe and efficient covalently acting drugs. In another strategy to modify the reactivity of the cysteine reactive warhead functionality of irreversible kinase inhibitors, 3-aminopropanamides that can be converted intracellularly to acrylamides have been prepared [18]. Here focus is on designing molecules that have a tight optimized binding to the target through reversible interactions and only when the electrophilic moiety is in close proximity to a nucleophilic residue in the targetbinding pocket will a covalent bond be formed.…”