Synthesis and cytotoxicity of novel indirubin-5-carboxamides

Indirubins have been reported to act as potent inhibitors of protein kinases relevant to tumorigenesis and of tumor cell growth, but their development to antitumor drugs suffer from their poor water solubility. We synthesized a novel class of indirubin derivatives, indirubin-5-carboxamides, carrying amide substituents with basic centers. Quaternization or protonation of these alkylamino substituents provided indirubins with significantly improved solubility without loss of bioactivity.

A series of indirubin-5-carboxamides was synthesized and evaluated for tumor cell growth inhibitory activity and solubility. Indirubins carrying amide substituents with basic centers show significantly enhanced solubility without loss of bioactivity.Figure optionsDownload as PowerPoint slide