BIOMIMETIC MEMBRANE-TRANSPORT - INTERESTING IONOPHORE FUNCTIONS OF NATURALLY-OCCURRING POLYETHER ANTIBIOTICS TOWARD UNUSUAL METAL-CATIONS AND AMINO-ACID ESTER SALTS

In an effort to develop new functionalities of naturally occurring ion ophores, we designed a new ''biomimetic membrane transport'' system me diated by monensin, lasalocid, and salinomycin. Under nonbiological co nditions, these ionophores specifically transported unnatural guest sp ecies such as amino acid ester salts and heavy and transition metal ca tions. Liquid-liquid extraction and C-13-NMR binding experiments clear ly demonstrated that these biological ionophores accommodated various guest cations in their pseudocavities and that the overall transport r ate was significantly determined by a combination of rates of guest bi nding and releasing processes. Several biomimetic applications can be envisaged using these ionophores in the border regions between synthet ic and biological supramolecular chemistry.