ISOLATION OF BIOLOGICALLY ACTIVE SUBSTANCES OF PHENOLIC NATURE FROM THE LICHEN HYPOGYMNIA PHYSODES

Abstract

A comparative analysis of the efficiency of extraction of phenolic compounds (low molecular weight phenols, flavonoids, atranorin) from the lichen thallus of the species Hypogymnia physodes using various extraction methods was carried out: maceration, exhaustive extraction in a Soxhlet apparatus, extraction under the action of a microwave field, and supercritical fluid extraction. It has been established that during extraction in the Soxhlet apparatus, among the studied extractants (ethanol, acetone, chloroform, water), ethanol allows extracting the largest amount of low molecular weight phenols and flavonoids from the lichen thallus: up to 8.4% of the absolutely dry weight of the lichen, while the highest degree of extraction atranorine is achieved by extraction with acetone: up to 4.1% of the absolutely dry weight of the lichen. The method of maceration with 96% ethanol makes it possible to extract up to 3.8% of phenolic compounds from the absolutely dry mass of lichen, while it was found that the optimal duration of the process for the isolation of low molecular weight phenols and atranorine is 60 minutes, and for flavonoids - 120 minutes. It has been shown that the use of microwave treatment during maceration with 96% ethanol does not lead to an increase in the yield of phenolic compounds, which is commensurate with that during maceration without additional treatment. It has been established that during supercritical fluid extraction, there is a high selectivity to the group of compounds of a phenolic nature: their content in the extract reaches 90.8% of the total yield of dry substances, but their yield only slightly increases (up to 8.9% of the absolutely dry mass of lichen) in compared with Soxhlet extraction.