The dependence of the distribution of ionophoric macrotetrolide antibiotics on the composition of their immiscible phases

Influence of various solvents on the content of macrotetrolides during their prolonged storage in solution was shown. Under the conditions of room temperature 90 per cent acetone induced hydrolysis of polyether antibiotics. 90 per cent ethanol and dry chloroform induced respectively slight and intensive cyclization of linear precursors (oxyacids). The study on distribution of macrotetrolides between immiscible phases of various composition revealed that addition of ethanol or acetone to the water-chloroform system of organic solvents induced the antibiotic liberation into the water phase which increased with increasing concentration of the substances being added. Inorganic cations intensified the process during either the oxyacid cyclization or the antibiotic hydrolysis and liberated the reaction products from the equilibrium mixture. Under such conditions the value of the ion radius or selectivity of the macrotetrolides to definite cations was in principle of no importance.