– Amustaline (S-303) dihydrochloride is a nucleic acid-targeted alkylator recognized for its efficacy as a pathogen inactivation agent in blood components containing red blood cells. This compound comprises three key elements: an acridine anchor (a non-covalently bonding intercalator targeting nucleic acids), an effector (a bis-alkylator group that interacts with nucleophiles), and a linker (a flexible carbon chain with a labile ester bond, hydrolyzing at neutral pH to non-reactive products).