Advances in Chemistry Research. Volume 57 begins with a focus on structures which core-modified porphyrins and derivatives adopt, as well as a comparison of electronic properties, including aromaticity, of core-modified porphyrins and common tetrapyrroles. Perspectives of studies and applications of core-modified tetrapyrroles are considered as well. Following this, the authors provide a brief introduction to solvation processes in pure solvents, followed by an extension of the topic to mixtures, and a thorough analysis of preferential solvation phenomena. In one study, Rhodobacter sphaeroides cytochrome c oxidase is prepared, in which n terminal histidines 3, 7, and 10 of subunit III have been replaced with glutamine residues and enzymatic activities of the isolated mutant enzyme assessed. Different aspects of the problem of the oxo-atom transfer of organometallic complexes in oxidation reactions of some organic compounds with dioxygen, under UV-irradiation, are discussed. Examples demonstrating the catalytic properties of dioxo-Mo-complexes in oxidation of the chlorinated derivatives of mono- and biphenyl substituted alkanes are presented. The authors also examine plant biomass-based substrates or waste coproducts that have been examined to determine whether they could support pullulan synthesis by the fungus A. pullulans, and identify which show the most promise for commercial pullulan production. In conclusion, clustering in aqueous solutions of H2CO3 and NaHCO3 in the mass range from 100 to 200 thousand Dalton is studied by way of gravitational mass spectroscopy. The formation of ensembles of clusters obeying the first and second Zubov equation was found.