Usnic acid (UA) was extracted from Usnea longissima (L.) Ach. in supercritical carbon dioxide (SC-CO2 ) medium. The selected process parameters were extraction temperature (35–45 °C), amount of co-solvent (0%–5%) and extraction time (5–9 h). These parameters were applied to Box-Behnken design (BBD) belonging to response surface methodology (RSM) to determine optimum process parameters for the highest amount of UA in the extract. g UA/100g lichen, extraction yield % and UA content values were calculated in the range of –, – and 71%–82% in different experimental conditions, respectively. The optimum conditions were predicted as 42 °C, (ethanol) and h. It was determined that the predicted and experimental values of g UA/100g lichen were compatible, and the suggested model was valid. |
