[UV-spectroscopic study of complex formation between nonactin and picrates of monovalent cations].

A macrotetrolide preparation including nonactin (about 75 per cent), monactin (about 23 pr cent) and traces of dinactin and trinactin was analyzed with the method of UV spectroscopy. It was shown to form hydrophobic complexes in organic solvents with picrates of univalent cations of ammonium, potassium and sodium. The complex strength depended not only on the cation nature, but also on the solvent and pH of the picrate aqueous solutions. The comparison of methylene chloride used for tetrananactin with chloroform demonstrated that nonactin formed stable complexes in chloroform at neutral pH of the aqueous phase, a solution of picric acid and ammonium chloride.