C2-symmetrical sterol–polyether conjugates as highly efficient synthetic ionophores

A new class of artificial ionophores has been rationally designed and synthesized linking to a tetrafunctionalized l -treitol spacer two rigid hydrophobic 3β-hydroxy-5α-23,24-bisnorcholanic units and two flexible hydrophilic oligo(ethylene glycol) chains. Compounds 1a and 1b were incorporated into phospholipid vesicles and shown to facilitate Na+-transport.