CC-1065 and the duocarmycins are highly potent anticancer agents, exerting their biological activity through covalently reacting with adenine-N3 in the minor groove of AT-rich sequences. The alkylation properties and cytotoxicity of a series of novel chiral analogues are reported in this thesis. Structural modifications of established pharmacophores resulting in novel alkylating functionalities as well as variations of the DNA binding domain were introduced in the analogues considered, The sequence specificity of these compounds was assessed by a Taq Polymerase stop assay, identifying the sites of covalent modification on plasmid DNA and the purine-N3 adducts probed by a thermally-induced strand cleavage assay. The cytotoxic potency of the analogues was determined against human, chronic myeloid leukemia, K562, cells, using a MTT based growth inhibition assay. The importance of the chiral centre present in the natural products was subsequently investigated with a series of achiral analogues. The studies established that the chiral centre is not absolutely required for DNA interaction and cytotoxicity. This finding offers the possibility of a new platform for the design of novel, active CC-1065/duocarmycin analogues. A key chiral and an achiral analogue were selected for DNA repair studies. The sensitivity of yeast mutants deficient in specific DNA repair pathways was assessed in order to delineate the mechanisms involved in the repair of the relevant adenine-N3 adducts. Nucleotide excision repair (NER) and post replication repair mutants were the most sensitive to the two analogues. Single-strand ligation PCR was employed to follow the induction and repair of the lesions at nucleotide resolution. Adduct elimination of both agents was by transcription-coupled NER, and dependent upon functional Radl8. Finally, the involvement of NER as the predominant excision pathway was further confirmed in mammalian DNA repair mutant cells
