Quinone Methides and Their Biopolymer Conjugates as Reversible DNA Alkylating Agents

In this review, we discuss the advances in understanding the reactivity of quinone methide (QM) intermediates and the reversibility of DNA alkylation by QMs in the past two decades. QMs react with strong nucleophiles of DNA under kinetic control but reversibly. The effective lifetime of QMs can be extended through repeated capture and release from DNA adducts. A QM-acridine conjugate DNA cross-linking agent remains dynamic and “migrates” among DNA strands through multiple strand exchange reactions until forming stable adducts irreversibly. Self-adducts of QM-biopolymer conjugates exhibit strong capability to alkylate complementary DNA strands in a sequence specific manner.