Résumé : Inorganic phosphate homeostasis is regulated by the concerted work of different phosphate transport proteins, whose malfunction can lead to a variety of diseases.[1] A potential treatment for such diseases could be the use of small synthetic molecules that mimic the behaviour of transport proteins.[2] Achieving selectivity for oxyanions over more simple spherical anions (e.g. chlorides, fluorides) is yet a challenging task. Because of the strong hydration energies (which makes extraction from the aqueous phase into the apolar interior of the lipid bilayer more difficult) and the speciation of inorganic phosphates with multiple negative charges (H2PO4− and HPO42−), extraction and transport of phosphorylated compounds are particularly difficult. The key to transporting and extracting such highly hydrated anions is the formation of multiple H-bonds to the anion.[3]Here we report the first examples of inorganic phosphate transport based on strapped calix[4]pyrrole supramolecular structure.[4] Volume-specific sites with multivalent interactions allowed the extraction of strongly hydrated H2PO4− into the lipid bilayer while shielding its charges from the lipophilic bilayer interior and transferring them through the membrane. Phosphate transport was monitored by emission spectroscopy using an encapsulated phosphate sensitive europium(III) probe.[5] Furthermore, the 31P-NMR spectroscopy assay was used to confirm and identify the transported phosphate species.