[The role of metabolic and regulatory factors in the mutagenic activity of purine derivatives in microorganisms]. / Rol' metabolicheskikh i reguliatornykh faktorov v proiavlenii mutagennoi aktivnosti purinovykh proizvodnykh u mikroorganizmov.

The results concerning analysis of the mutagenic activity of analogues of nitrogen bases are given for Saccharomyces cerevisiae, Streptomyces antibioticus, Bacillus subtilis. The mutagenic activity of purine derivatives depends on their metabolic transformations in cell and on the activity of enzyme systems, involved in regulation of purine biosynthesis. The criterion of selection of purine analogues with genetic activity is proposed for yeasts, based on retroinhibitory ability of analogues of nitrogen bases.

[Epoxy ring scission in the oleandomycin molecule during aging]. / O raskrytii époksidnogo kol'tsa v molekule oleandomitsina v protsesse stareniia.

Opening of the epoxide ring in the molecule of oleandomycin phosphate in the process of its aging was shown to be possible by the data of the analysis. Certain correlation between the "glycol" content and drug activity was detected.

[Characteristics of the range of mutations in nystatin resistance induced in yeasts by 6-N-hydroxylaminopurine]. / Osobennosti spektra mutatsii nistatinustoichivosti, indutsirovannykh u drozhzhei 6-N-gidroksilaminopurinom.

A simple procedure for induction of nistatin-resistant mutants in yeasts under the action of 6-N-hydroxylaminopurine (HAP) is proposed. Some differences between the spectra of mutations induced by HAP and UV-light are observed: HAP induces dominant and double recessive mutants more frequently.