Two series of novel alkoxylated 2-oxo(imino)-3-pyridinecarbonitriles (structurally-relevant to some reported anticancer pyridines with phosphodiesterase 3A (PDE3A) inhibitory activity) were synthesized and evaluated for their in vitro differential tumor cell growth inhibitory potential against the breast MCF7, hepatocellular Hep-G2, colon CACO-2 cell lines, and a normal human foreskin fibroblast Hs27 cell line. Compounds 8, 16 and 19 displayed recognizable growth inhibitory ability and selectivity towards the breast MCF7 (LC50 19.15, 17.34 and 14.70 µM, respectively) as compared with doxorubicin (LC50 3.94 µM). Meanwhile, compounds 8, 15, 16, and 19 revealed a marginal inhibitory effect on the growth of the normal human foreskin fibroblast Hs27 cell line, beside a distinctive antioxidant potential in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. These four compounds were further assessed for their in vitro inhibition of PDE3A (a current antitumor therapeutic target), where 16 and 19 showed moderate to weak PDE3A inhibitory as compared with milrinone, the positive control. No clear straightforward liaison between the anticancer potential and PDE3A inhibitory activity could be deduced. Computations of the predicted pharmacokinetic properties, toxicity effects (ADME-T), drug-likeness and drug scores for the newly developed compounds showed non-violations of Lipinski's RO5 and Veber's criteria for good bioavailability, with a predicted high safety profile.
Keywords: anticancer; antioxidant; pharmacokinetic property and effect (ADME-T); phosphodiesterase-3A (PDE3A); pyridine.