[Binding of adenosine analogs with A1-type purine receptors in the guinea pig ileum]. / Izuchenie sviazyvaniia analogov adenozina s purinovymi retseptorami A1-tipa v podvzdoshnoi kishke morskoi svinki.

Several N6-adenosine analogs were synthesized and their A1-purine receptor binding affinities were determined. Our results demonstrate that N6-allyl- and N6-aminopropanol-adenosine increase affinities to A1-purine receptor in guinea pig ileum.

[Inactivation characteristics of polyene macrolide antibiotics]. / Nekotorye osobennosti inaktivatsii polienovykh makrolidnykh antibiotikov.

Roseofungin, a pentaen was used as an example in investigation of certain characteristics of inactivation of polyenic antibiotics. An inactivation product of the antibiotic having no antiviral or antimycotic activity was isolated by TLC and column chromatography on Sefadex LH-20. UV, IR and EPR spectroscopy showed that this product was cys-tetraen without conjugation of the lactone carbonyl to the polyenic system.

[Interaction of the polyene antibiotic nystatin with bivalent copper ions]. / Osobennosti vzaimodeistviia polienovogo antibiotika nistatina s ionami dvukhvalentnoi medi.

Characteristic features of interaction of nystatin with bivalent copper salts in water, methanol and dimethylsulfoxide were studied. It was shown that stable compounds of copper and nystatin at ratios of 1 : 2 and 1 : 4 formed in the above solvents. The antibiotic in these compounds was in an inert, native or activated state. Physicochemical and biological properties of the compounds were investigated.

[Physiochemical characteristics of 3 states of the nystatin molecule]. / Fiziko-khimicheskie osobennosti trekh sostoianii molekuly nistatina.

Conditions for production of nystation in three main states, i.e. inert, native and activated were determined. It was found that nystatin used in medical practice is in the inert state which is most stable for this antibiotic. Under certain conditions this state is transferred into the native or activated state. Solid forms can be prepared. The native and activated states are significantly less stable. The physicochemical characteristics of these nystatin states are presented. The data obtained can be used for the development of effective methods for nystatin production and purification.

[Acid-base properties of the polyene antibiotic nystatin]. / Kislotno-osnovnye svoistva polienovogo antibiotika nistatina.

The acid-base properties and transformation of nystatin in water, methanol, 80 per cent ethanol, 70 per cent propanol and 70 per cent dimethylsulfoxide were studied. The data are indicative of a significant difference in the protolytic properties of the antibiotic in various solutions. Nonreversible conformative conversions of nystatin in water and methanol not connected with the loss of the antibiotic activity were observed. It is suggested that the molecule of nystatin in the above solutions could be in 3 main states, i. e. inert native and activated. The results of the study may be of use in development of the schemes for isolation of nystatin from the mycelium preparation of some of its water soluble forms.