Fluorescent 7-diethylaminocoumarin pyrrolobenzodiazepine conjugates: synthesis, DNA interaction, cytotoxicity and differential cellular localization.

The pyrrolo[2,1-c][1,4]benzodiazepines (PBDs) are a class of DNA minor groove binding agents that react covalently with guanine bases, preferably at Pu-G-Pu sites. A series of three fluorescent PBD-coumarin conjugates with different linker architectures has been synthesized to probe correlations between DNA binding affinity, cellular localization and cytotoxicity. The results show that the linker structure plays a critical role for all three parameters.