UV spectra of pyrimidine bases and nucleosides in the context of methylsubstitution and interaction with amino acid carboxylic group

UV spectra of pyrimidine nucleotide bases, nucleosides, a number of their derivatives and analogues were investigated in anhydrous DMSO. Effects of interaction with neutral and deprotonated carboxylic group of amino acids on the UV spectra were traced. It was established that methylation of pyrimidine bases at the positions 1 and 5 leads to the 5–12 nm bathochromic shift of the absorption bands. The majority of the Cyt derivatives excluding m