In the last few years, our research group has designed a new family of polyamine compounds consisting of a macrocyclic pyridinophane core substituted with side chains containing additional donor atoms. These macrocycles are called scorpiand ligands. We have analysed the in vitro activity of some of these compounds and their derivatives against Trypanosoma cruzi and two species of Leishmania. We also studied their anti-parasitic, anti-inflammatory and anti-tumour activity, both in vitro and in vivo, and by theoretical methods.