Key words: lichen, Usnea subfloridana, usnic acid, supercritical fluid extraction, rotable compositional uniform plan
The process of SCF-extraction of usnic acid from Usnea subfloridana has been optimized using a rotatable compositional uniform plan of the 2nd order. The effect of pressure, temperature and the duration of the process on the yield of the extract is evaluated. According to the model used, the optimal conditions for the extraction process are proposed: duration 80 minutes, temperature 85 °C and pressure 150 atm. The predicted yield of the extract (1.19 %) under these conditions is experimentally confirmed (1.11 %). Antibacterial activity against Escherichia coli bacteria and microorganisms of the species Staphylococcus aureus and Bacillus subtilis was revealed.
doi:10.34984/SCFTP.2019.14.4.002