Bioisosteric replacement of an acylureido moiety attached to an indolin-2-one scaffold with a malonamido or a 2/4-pyridinoylamido moiety produces a selectively potent Aurora-B inhibitor.

Abstract Bioisosteric replacement of acylureido moiety in 6-acylureido-3-pyrrolylmethylidene-2-oxoindoline derivatives resulted in a series of malonamido derivatives with indolin-2-one scaffold ( 11 – 14 ). Further conformational restrictions of the malonamido moiety led to 2-oxo-1,2-dihydropyridine ( 21 – 25 ) or a 4-oxo-1,4-dihydropyridine derivatives ( 31 – 36 ). 4-Oxo-1,4-dihydropyridine derivatives were more potent Aurora B inhibitors than their 2-oxo-1,2-dihydropyridine counterparts and demonstrated cytotoxicities against A549 and HepG2 cells in the submicromolar range. In A549 cells, 31h decreased phosphorylation of histone H3, triggered polyploidy, induced expression of pro-apoptotic Fas and FasL with subsequent activation of caspase 8, resulting into apoptosis. In a Huh7-xenograft mouse model, 31h demonstrated potent in vivo efficacy with a daily dose of 5 mg/kg.