[Biological action and complex-forming properties of a macrotetrolide antibiotic complex].

Macrotetrolide antibiotic complexes containing 60-80 per cent of nonactin were studied and their high antibacterial activity was shown. The macrotetrolides had a disintegrating effect on the bacterial membrane, which was evident from induction of the protoplast lysis and release of low-molecular compounds from the bacterial cells. The complex-forming properties of nonactin with respect to the ammonium, potassium and sodium ions were investigated in vitro. The selectivity level with respect to the ammonium ions was higher. Nonactin incorporated into an artificial membrane provided a linear dependence of the delta mV on the ammonium chloride concentration within the ranges of 10(-1)-10(-5) M.