Four series of phenylpicolinamide derivatives bearing 1H-pyrrolo[2,3-b]pyridine moiety (12a-e, 13a-f, 14a-f and 15a-i) were designed, synthesized and evaluated for the IC50 values against three cancer cell lines (A549, PC-3 and MCF-7) and c-Met kinase. Five selected compounds (13b, 15b, 15d, 15e and 15f) were further evaluated for the activity against HepG2 and Hela cell lines. Eighteen of the compounds showed excellent cytotoxicity activity and selectivity with the IC50 valuables in single-digit μM to nanomole range. Seven of them are equal to more active than positive control Foretinib against one or more cell lines. The most promising compound 15f showed superior activity to Foretinib, with the IC50 values of 1.04±0.11μM, 0.02±0.01μM and 9.11±0.55μM against A549, PC-3 and MCF-7 cell lines, which were 0.62 to 19.5 times more active than Foretinib (IC50 values: 0.64±0.26μM, 0.39±0.11μM, 9.47±0.22μM), respectively. Structure-activity relationships (SARs) and docking studies indicated that replacement of quinoline nucleus of the previous active compounds with 1H-pyrrolo[2,3-b]pyridine moiety maintained even improved the potent cytotoxic activity. The results suggested that the introduction of fluoro atoms to the aminophenoxy part of target compounds or the phenyl group of pyrimidine substituted on C-4 position was benefit for the activity.
Keywords: 1H-Pyrrolo[2,3-b]pyridine; Antitumor activity; Docking; Phenylpicolinamide; Synthesis; c-Met inhibitors.
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