Introduction of the α-ketoamide structure: en route to develop hydrogen peroxide responsive prodrugs

Leveraging the elevated levels of hydrogen peroxide (H(2)O(2)) in cancer, inflammatory diseases and cardiovascular disorders, H(2)O(2)-activated promoieties have been widely used in drugs and biomaterials design. However, the overwhelming majority of the promoieties only share the common structure of a H(2)O(2)-responsive arylboronic acid/ester moiety with low diversity. We report here an unprecedented strategy to construct novel H(2)O(2)-responsive prodrugs based on an α-ketoamide structure. As a proof of concept, we designed and synthesized a panel of α-ketoamide based nitrogen mustard prodrugs, among which KAM-2 showed potent growth inhibitory activity and high selectivity toward cancer cells. The H(2)O(2)-trigged decomposition of KAM-2 was validated, and the DNA damaging and apoptosis promoting activity attributed to the released nitrogen mustard were demonstrated. Our work unveils α-ketoamide as a new scaffold for prodrug design and may quickly inspire future developments.