Département de chimie moléculaire

G-quadruplex DNA ligands attract much attention because of their potential use in biol. Indeed they may interfere with G-quadruplex nucleic acid function in cells. Most of the G-quadruplex ligands so far reported (including also metal complexes) are large planar arom. compds. that interact by $π$-$π$ stacking with an external G-quartet of quadruplex. Porphyrins are known G-quadruplex ligands. The authors report herein a new porphyrin scaffold (meso-tetrakis(4-(N-methyl-pyridinium-2-yl)phenyl)porphyrin) able to strongly and selectively bind to G-quadruplex DNA. Even when this porphyrin is metalated with cobalt(III), i.e. it carries two water mols. as axial ligands on the cobalt ion, on each face of the porphyrin, the interaction occurs by a $π$-stacking-like mode with an external G-quartet of quadruplex DNA. [on SciFinder(R)]