The recognition of higher-order G-quadruplex by chiral cyclic-helicene molecules.

: The G-quadruplex structures represent a new class of molecular targets for DNA-interactive compounds that might be useful for targeting telomeres. Here we describe a study on the structure-based design of cyclic helicenes displaying chiral and steric selection in binding to higher-order G-quadruplexes. We propose a new ligand-binding site for G-quadruplex-binding compounds. These results provide proof of concept for small molecule inhibitors of telomerase associated with higher-order G-quadruplex structures.