Antiproliferative properties of iron supramolecular cylinders

The use of metallohelicates as potential antiproliferative agents is mostly exemplified by one sole family of supramolecular compounds that is based on bis-iminopyridine ligands. In the present investigation, two other types of metallocylinders have been selected and their potential DNA-binding and cytotoxic properties have been investigated. Hence, two new neutral iron(III) metallosupramolecular compounds have been prepared from bis-β-diketone ligands, and a known cationic iron(II) helicate from bis-pyrazole ligands has been used for comparison purposes. DNA-interaction experiments and cell studies reveal remarkable biological properties for one of the neutral iron cylinders and the positively charged, pyrazole-based helicate, as illustrated by their antiproliferative behaviours, which are far better than those of two well-known compounds, i.e. the most studied metallohelicate in the field and cisplatin.