Natalya Sh. Lebedeva

Synthesis and biological evaluation of novel tyrosyl-DNA phosphodiesterase 1 inhibitors with a benzopentathiepine moiety.

Tyrosyl-DNA phosphodiesterase 1 (TDP1) is a promising target for antitumor therapy based on Top1 poison-mediated DNA damage. Several novel benzopentathiepines were synthesized and tested as inhibitors of TDP1 using a new oligonucleotide-based fluorescence assay. The benzopentathiepines have IC₅₀ values in the range of 0.2-6.0 μM. According to the molecular modeling, the conformational flexibility of the dibutylamine group of the most effective inhibitor (3d) allows it to occupy an advantageous position for effective binding compared to its cyclic counterparts. The study of cytotoxicity of these compounds revealed that all compounds cause an apoptotic cell death in MCF-7 and Hep G2 cells. Therefore the new class of very effective inhibitors of TDP1 was elaborated.

Spectral and hydrodynamic studies of complex formation of tetraalkoxy substituted zinc(II)phthalocyanines with defatted and nondefatted bovine serum albumin

Spectral, hydrodynamic and thermochemical studies have been demonstrated that tetraalkoxy substituted zinc(II)phthalocyanines form stable complexes with defatted and nondefatted bovine serum albumin. The phthalocyanines interact with BSA through heteroatoms of their peripheral substitutes. It was found that ZnPc(4-NH-CO-C6H4-OC3H7)4 is located in the protein subdomains IB and IIA whereas ZnPc(4-NHCO-C6H4-OC6H13)4 and ZnPc(4-NH-CO-C6H4-OC8H17)4 are immobilized on surface of the protein globule at a distance of not greater than 10 nm from the tryptophan residues in the positions 135 and 214 of the protein polypeptide chain. Zinc(II)phthalocyanines (ZnPc(4-NH-CO-C6H4-OC6H13)4 and ZnPc(4-NH-CO-C6H4-OC8H17)4) increase thermal stability of BSA.

The interaction of cationic and anionic porphyrins with the bovine serum albumin in borate buffer

The interaction of water-soluble porphyrins with the bovine serum albumin in borate buffer at pH 8.6 has been studied. The localization of porphyrins in the protein globule has been determined. It was established that the native conformation of albumin upon binding with the porphyrins is preserved, however, the anionic porphyrins are exhibit wedging effect on the albumin domains. The binding constants were obtained from fluorescence spectroscopy data.

A new strategy for targeted delivery of non-water-soluble porphyrins in chitosan-albumin capsules

AbstractThis study was focused on obtaining polymer complex of 5-(4′-N-tert-butyloxycarbonylglicinaminophenyl)-10,15,20-triphenylporphine and 5-(4′-amonophenyl)-10,15,20-triphenylporphine with chitosan. The polymer complexes were characterized spectrally and calorimetrically. The existence of a substituent capable of forming hydrogenic complexes with proteins and other biopolymers in porphyrins provides an effective immobilization of a photosensitizer. Binding with porphyrins was found to result in twisting the chitosan globule and encapsulation of porphyrins. Coating of polymer complex with bovine serum albumin promotes neutralization of zeta potential and formation of 180-nm capsules. As the result of the study, a new universal strategy of water insoluble preparation encapsulation in biopolymers for targeted delivery of drugs and their further release was suggested. Graphical abstractᅟ

Thermodynamic aspects of interaction zinc(II)tetraphenylporphyrin with bidentate ligands in dilute solutions

Molecular complex formation of zinc(II)tetraphenylporphyrin with the ligands—diamino compounds in toluene was studied using calorimetric and spectroscopy titration. The structure of the complexes has been confirmed using 1H NMR and fluorescence spectroscopy. Nature of the interaction between the ligand and the solvent was established using TGA of solvates.

Pedagogy and educational democratization: The problem of alienation

Education is viewed as not merely a particular domain of social life. It is more a universal process than a mere learning of sciences and arts; it is richer than an individuals socialization. The educational democratization turns out to be a prerequisite of humanization of the entire social life. The orientation at the supreme humane values as a strategic direction of democratic evolution of education is opposed to the authoritarian tendencies as an “antivalue” of pedagogical relations.Being a significant step towards a genuinely humane society, democratization is unable, however, to resolve the fundamental problem of human formation: that of alienation. The opportunity to resolve it is dependent upon proper conditions for a free self-determination of a personality in culture.