Anion-Selective Cholesterol Decorated Macrocyclic Transmembrane Ion Carriers.

Anion transporters play a vital role in cellular processes and their dysregulation leads to a range of diseases such as cystic fibrosis, Bartter's syndrome and epilepsy. Synthetic chloride transporters are known to induce apoptosis in cancer cell lines. Herein, we report triamide macrocycles that are easily synthesized and externally functionalized by pendant membrane-permeable groups. Among a variety of chains appended onto the macrocycle scaffold, cholesterol is found to be the best with an EC50 value of 0.44 μM. The macrocycle is highly anion-selective and transports ions via an OH- /X- antiport mechanism. The macrocycle is an interesting scaffold for ion-transport as it is able to discriminate between various anions and shows a preference for SCN- and Cl- . Such anion-selective transporters are highly attractive model systems to study ion-transport mechanisms and could potentially be of high therapeutic value.