Prodigiosin is one of the most potent anion transporters in lipid bilayer membranes reported to date. Inspired by the structure of this natural product, we have recently designed and synthesised a new class of H+/Cl− cotransporters named 'perenosins'. Here we report a new library of indole-based perenosins and their anion transport properties. The new transporters demonstrated superior transmembrane transport efciency when compared to other indole-based transporters, due to favourable encapsulating efects from the substituents on the perenosin backbone. Anion transport assays were used to determine the mechanism of chloride transport revealing that the compounds function as 'strict' HCl cotransporters. Cell viability studies showed that some compounds specifcally trigger lateonset cell death after 72h with a unique correlation to the position of alkyl chains on the perenosins. Further investigations of cell death mechanism showed a mixture of cell cycle arrest and apoptosis was responsible for the observed decrease in cell viability.