[Polyene antibiotic solubilization by bile acid salts in aqueous solutions]. / Soliubilizatsiia polienovykh antibiotikov soliami zhelchnykh kislot v vodnykh rastvorakh.

The process of solubilization of polyenic antibiotics, such as amphotericin B, mycoheptin, levorin and nystatin in aqueous solutions of sodium salts of bile acids: desoxycholic, cholic and dehydrocholic was studied. It was shown that amphotericin B and mycoheptin had the highest capacity for solubilization. No solubilization of the antibiotics was observed in the solutions of sodium dehydrocholate. Thermodynamic estimation of the solubilization process with sodium desoxycholate is presented.

[Surface activity of polyene antibiotics]. / O poverkhnostnoi aktivnosti polienovykh antibiotikov.

The surface activity properties of polyenic antibiotics, such as amphotericin B, mycoheptin, levorin and nystatin were studied. The critical concentrations for the mycella formation were determined and the values of the polyenic antibiotic surface activity at various temperatures were estimated. It was found that the process of the mycella formation of polyenic antibiotics was defined by a positive change in the entropy. A thermodynamic analysis of the process of the mycella formation of the polyenic antibiotics in aqueous solutions was performed.

[Ionization of the acid-base groups of polyene antibiotics in aqueous solutions]. / Ionizatsiia kislotno-osnovnykh grupp polienovykh antibiotikov v vodnykh rastvorakh

The acid-base characteristics of polyenic antibiotics, such as nystatin, mycoheptin and levorin in aqueous solutions were studied. A special procedure provided the use of potentiometric titration for investigation of ionization of the groups of vater-insoluble substances. The ionization constants of the carboxylic and amine groups of the antibiotics at several temperatures were determined. It was found that ionization of the acid group did not practically depend on the temperature. At the same time the heat effect of the amine group ionization was significant and amounted to about 10 kcal/mole. Thermodynamic analysis of the ionization process of the polyenic antibiotics in aqueous solutions was performed. Integral components defining the process energetics were calculated.

[Acid-base properties and the thermodynamics of amphotericin B ionization in aqeous solutions]. / Kislotno-osnovnye svoistva i termodinamika ionizatsii amforteritsina B v vodnykh rastvorakh

Acid-base properties of amphotericin B, polyenic antibiotic in aqueous solutions was studied. A special procedure provided the use of potentiometric titration for investigation of ionization of the groups of the water-insoluble substance. The ionization constants of the carboxylic and amine groups of the antibiotic were determined at several temperatures. It was found that ionization of the acid group did not depend on the temperature. At the same time the heat effect of the amine group ionization was significant and amounted to about 10 kcal/mole. Thermodynamic analysis of the ionization process of amphotericin B in aqueous solutions was performed. Integral components defining the process energetics were calculated.