POLYPHENOLS OF ARCTIC BROWN ALGAE: EXTRACTION, POLYMOLECULAR COMPOSITION

Abstract

Arctic brown algae of the species Fucus vesiculosus are characterized by a high content of polyphenolic compounds - phlorotannins, exhibiting high biological activity. The aim of this study is to develop a methodology for the isolation and analysis of biologically active polyphenolic compounds from arctic brown algae. The proposed scheme for the isolation of polyphenols from Fucus vesiculosus brown algae is based on the principles of "green chemistry" and is carried out by sequential disassembly of the biomass of the plant object with the release of associated components (lipid-pigment complex, polysaccharides, mannitol) and maximum yield of polyphenol fraction. As a result of the experimental work, the optimal parameters for carrying out each stage of the proposed scheme were determined and a stepwise assessment of its effectiveness was carried out. The extractable fraction of polyphenols contains up to 67% of polyphenols relative to their content in the initial biomass, and the proportion of polyphenols in the fraction is up to 83%. A study of the phlorotannins fraction showed that its antioxidant activity is meaningful and it was 553±24 (mg of ascorbic acid/g extract). The polymolecular composition of the target fraction was investigated by the method of exclusion gel filtration chromatography, which showed the polymodal distribution, indicating the presence of several groups of components - low molecular weight and high molecular weight phlorotannins with masses ranging from thousands to hundreds of thousands of Daltons. The data obtained using chromatography-mass spectrometry and MALDI mass spectrometry make it possible to identify the presence of low molecular weight phlorotannins in the polyphenol fraction with masses from 250 to 1638 Da, which are close analogues in structure.