Aim. The pharmacophores based on the combination of mononucleotides with biomolecules are currently being developed. It is therefore important to study both their interaction and mononucleotides themselves. One of the most common approaches is the use of spectroscopic methods, which provide important information such as electronic transition energies. However, the spectroscopic studies of the emission of aqueous solutions of nucleotides are typically carried out at 77,4 K or 4,2 K. This approach does not permit to study the nucleotides in their natural cellular state. Furthermore, the majority of spectroscopic studies of mononucleotides to date have focused on their salts. At the same time, nucleotides in their acidic form can exhibit markedly different properties from their salts. In addition, the preliminary studies in our laboratory have shown that the complexes of nucleotide acids with mannitol have anti-inflammatory, immunomodulatory, and antiviral activity. Therefore, the aim of this work was to analyse and compare their spectral properties in conditions close to biological systems. Conclusions. The obtained spectra permit to reveal the interaction of bases, nucleosides and nucleotides with D-mannitol. In addition, in some cases, the interaction of nucleotides of acidic and salt forms with D-mannitol differed. It was noted that this primarily concerned adenosine monophosphate and guanosine monophosphate, which contain purine bases.