units. The type of heterocyclic part influenced their cytotoxic and anti-proliferative properties. Coupling of MPA 1 with 9-(ω-aminoalkyl)amino-1-nitroacridines 2 and 1-[(ω-aminoalkyl)-4-nitro-9(10H)]-acridones 3 was tested. Although all tested conjugates were active, compounds 4a–e exhibited the highest potency. Preliminary experiments with GMP suggested that the tested compounds acted as IMPDH inhibitors