Novel malonamide derivatives as αvβ3 antagonists. Syntheses and evaluation of 3-(3-indolin-1-yl-3-oxopropanoyl)aminopropanoic acids on vitronectin interaction with αvβ3

Abstract

In attempt to find novel integrin of αvβ3 antagonists, we selected SC65811 and its guanidine analogue (1) as lead compounds. Modification of the glycine part of SC65811 led to a new series of malonamide derivatives that exhibited αvβ3 inhibitory activity. Among them, (R,S)-3-{3-[6-(3-benzylureido)indolin-1-yl]-3-oxopropanoylamino}-3- (pyridin-3-yl)propanoic acid (43a) showed not only potent activity with an IC50 value of 3.0 nM but also good selectivity for αvβ3 relative to αIIbβ3, α5β1, and αvβ5 with IC50 values of 19000, 11000, and 14 nM, respectively. Furthermore, optimization of 43a led to the most potent αvβ3 antagonist, (R,S)-3-(3-{6-[(4,5-dihydro-1H-imidazol-2-yl)aminoindolin-1-yl}- 3-oxopropanoylamino)-3-(quinolin-3-yl)propanoic acid (431) with an IC50 value of 0.42 nM. The synthesis and the structure-activity relationships of these malonamide derivatives are presented.