Synthesis and preliminary evaluation of novel analogues of quindolines as potential stabilisers of telomeric G-quadruplex DNA

Telomeric DNA is a potential selective target for cancer therapy since the tumour-associated enzyme telomerase regulates telomere maintenance in most cancer cells. The 3′ single-stranded ends of telomeric DNA can be folded into quadruplex structures by appropriate small molecules. We describe the preparation of a new class of 2,7-disubstituted 10H-indolo[3,2-b]quinolines with enhanced selectivity for the stabilisation of quadruplex DNA compared to duplex DNA, and also the preparation of a key intermediate for the synthesis of trisubstituted quindolines.