2.B.83.  The Cyclic Peptide Carrier (CPC) Family 

 Davis et al. 2020 have reported a new family of cyclic peptides (27, 28 – see the figure below).  These systems are proposed to dimerize through hydrogen-bonding interactions between the two cyclic peptides, with the pendant pyridines at each end of the dimer forming either anion or metal-ion binding sites. Behra and Madhavan have also used cyclic peptides, in their case decorated with cholesterol moieties as transmembrane anion carriers.

Transmembrane ion-pair co-transport can use synthetic transporters. Cyclic dipeptide ion-carriers with dangling ester motifs to bind cations and amide-NH to bind anions are amoung them. The pendant lipophilic norbornene units aid in membrane insertion to achieve MCl co-transport with this simple design (Hale and Madhavan 2023).

 

Cyclic peptide-based transporters 27 and 28.

 

References:

Davis, J.T., P.A. Gale, and R. Quesada. (2020). Advances in anion transport and supramolecular medicinal chemistry. Chem Soc Rev. [Epub: Ahead of Print]

Hale, U.A. and N. Madhavan. (2023). Hydrophobic cyclic dipeptides as M/Cl carriers. Chem Commun (Camb). [Epub: Ahead of Print]