STRUCTURE AND BIOMEDICAL PROPERTIES OF LIGNINS (REVIEW)

The proposed literature review is in line with current trends in the development of nature-like technologies and is devoted to the analysis of the chemical structure and the search for new ways to use lignins for biomedical applications. Lignins are unique biopolymers of plant origin, the structural organization of which is multivariate and largely depends on the biological species of the plant. Fundamental structural and chemical studies are increasingly clarifying our understanding of the macromolecules structure of this key plant biopolymer, and the study of various taxonomic origins lignins shows to what extent evolution and natural variability have led to a complication of the chemical structure of macromolecules, including through the inclusion of "unconventional" phenolic monomers. This suggests that lignins contain much more structural units than the three monolignol variants described in lignin chemistry textbooks. As a result, as the analysis of the literature data shows, the very definition of lignin continues to expand and refine. Currently, there is a dramatic increase in interest in lignin-based materials, mainly due to their diverse beneficial properties, such as biodegradability, reactivity, biocompatibility, low toxicity and a wide range of biological activity. One of the main objectives of this article is to identify and discuss the mechanisms of biological action of lignins on living organisms to assess the biomedical potential and substantiate the possibility of their use as innovative drugs of antioxidant, radioprotective and geroprotective action. Finding new ways to use lignins is necessary to meet the challenges of maintaining health and improving the quality and duration of people's lives.