Cyclic Octa‐ and Decapeptides as Ionophores for Magnesium

Abstract

Cyclic octa-and decapeptides have been prepared, and their ion selectivity in solvent polymeric membranes was studied. Cyclo(-LPro-DLeu-)5 behaves as an ionophore which selects Mg2+ over CaZ+ by a factor of 100.Cyclo(LPro-LLeu), induces selectivity in membranes for Mg2+ over Li+, Na+ and K' by a factor of 400,200 and 10, respectively, while selectivity of Mg2+ over Ca2+ is poor. Some evidence is presented which indicates that certain ionophores exhibit high selectivity for monovalent magnesium complexes.

Macrocyclic oxamides as ionophores for lead‐selective membrane electrodes

“…The influence of the concentration of KTpClPB (0-100 mol %) on the properties of the membranes was also investigated. It was found that in the absence of KTpCIPB, ionophores 1 and 7 show no activity in the membrane The fact that certain ligands behave as carriers only if lipophilic anionic sites are simultaneously present in the membrane phase has been observed earlier [9]. Also, the presence of KTpClPB exerts a decisive effect on the electrode response ( Figure 5).…”

History of the development of magnesium—selective ionophores and magnesium—selective electrodes

“…Alternatively, with cyclo(LPro-DLeu-), (Figure l(4)) and cyclo(LPro-DLeu-LPro-LLeu-LPro-Leu-DPro-LLeu-LPro-Leu-), the logarithmic selectivity coefficient over calcium ions was <-2 while the required selectivity over monovalent ions was lost (Behm et al: cyclic octa-and decapeptides as ionophores for magnesium) [16]. The influence of the concentration of anionic sites (KTpClPB, potassium-tetrakis-(4-~hlorophenyl)-borate) within the membrane on the selectivity scale of these carriers was tested.…”

Calorimetric Measurements of the Complexation of Cyclosporin A, Ascomycin, Fujimycin, and Rapamycin with Lithium Chloride and with an Immunophilin

“…I401 and the measurements of Simon and coworkers [41] with peptides for ion-selective membranes). We also plan to investigate the possible transport of ions through liposomes by these compounds.…”