Cysteine-Directed Bioconjugation of a Platinum(II)–Acridine Anticancer Agent

Classical maleimide Michael addition chemistry in conjunction with copper-free click chemistry was investigated as a synthetic strategy to attach cytotoxic platinum–acridine hybrid agents to carrier proteins. The structural integrity and selectivity of the model payloads, which were validated in human serum albumin (HSA) using mass spectrometric analysis and heteronuclear 2D 1H–15N HSQC NMR experiments, may have broad utility for the targeted delivery of highly cytotoxic platinum acridines and other nonclassical platinum containing anticancer agents.