[Hydration of complementary 9-methyladenine.1-methyluracil pairs at low temperatures according to data from field mass spectrometry].

The hydration of nucleotide bases of m9Ade(A), m1Ura(U) and a complementary pair A.U was studied by field ionization mass-spectrometry at room and low (170 K) temperatures in vacuum. Enthalpies of A.

[Effect of substituents on the heat of sublimation of nucleic acid nitrogenous bases].

Experimental results of the studieds of sublimation heats of some derivatives of nitrous bases of nucleic acids are presented. Effect of some substitutors on sublimation heats of purine and pyrimidine bases has been studie. The problem of the role of different intermolecular interactions in the stabilization of nitrous bases crystal structure is discussed on the basis of the data obtained.