Vitamin B12 and its derivatives are important biomolecules of porphyrin nature that work in supramolecular assemblies as cofactors performing vital functions in living organisms. They catalyze many molecular transformations in the cell metabolism (DNA synthesis and regulation), in carbon-skeleton rearrangements, and migration of functional groups.
We present the first nanostructures of vitamin B12 derivatives. They are nanoparticles of a unique type with strong noncovalent intermolecular interactions, functional properties, and activity that their constituent molecules do not possess. The nanoparticles were prepared by self-assembling of aquacyanocobyrinic acid heptabutyl ester under specially arranged conditions at the air-water interface into two-dimensional nanoaggregates. Characteristics of the structure and properties of nanostructured monolayers at the air-water interface were determined with the method of quantitative analysis of compression isotherms . The obtained data were used to select conditions favorable for the formation thin films on solid supports and to study them. AFM data indicate that the size of the 3D nanoaggregates in the plane of the substrate matches the theoretical estimate for the size of their 2D precursors. Photophysial study of nanoparticles demobstrate that they extend light absorption broadly covering visible and near infrared light, and their Soret and Q bands are strongly blue-shifted relative to the initial monomer solution.
The work was financially supported by the grant of the RSF (20-12-00175, film formation and study), ISUCT, and Ministry of Science and Higher Education of the RF (FZZW-2020-0008, synthesis of compounds).
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The results in this study are of interest because they approved a nanotechnological route for the formation of nanoparticles of biological compounds with novel properties and promising applications.