DNA Recognition with Polycyclic-Aromatic-Hydrocarbon-Presenting Calixarene Conjugates

New calix[4]arene conjugates that present polycyclic aromatic hydrocarbons (PAHs) at their exo rims have been synthesized by esterification of a cone-shaped calix[4]arenedicarboxylic acid with trans- or cis-pyrenylisoxazolidinyl alcohols prepared by a 1,3-dipolar cycloaddition methodology. The in vitro cytotoxic activities of all compounds were evaluated with three different human tumor cell lines, and the most potent one reached an IC50 of 95 nM. The different biological activities of the synthesized compounds were explained by docking and circular dichroism studies, which evidenced their intercalating abilities from the DNA minor groove.