We present and thoroughly characterize
a large collection of 3,4-dihydropyrimidin-2(1H)-ones
as A2BAR antagonists, an emerging strategy
in cancer (immuno) therapy. Most compounds selectively bind A2BAR, with a number of potent and selective antagonists further
confirmed by functional cyclic adenosine monophosphate experiments.
The series was analyzed with one of the most exhaustive free energy
perturbation studies on a GPCR, obtaining an accurate model of the
structure–activity relationship of this chemotype. The stereospecific
binding modeled for this scaffold was confirmed by resolving the two
most potent ligands [(±)-47, and (±)-38
K
i = 10.20 and 23.6 nM, respectively]
into their two enantiomers, isolating the affinity on the corresponding
(S)-eutomers (K
i = 6.30
and 11.10 nM, respectively). The assessment of the effect in representative
cytochromes (CYP3A4 and CYP2D6) demonstrated insignificant inhibitory
activity, while in vitro experiments in three prostate cancer cells
demonstrated that this pair of compounds exhibits a pronounced antimetastatic
effect.