Olive leaves (fruits) were placed into a three-neck flask
for ultrasonic and reduced-pressure extraction (URPE) under
the following conditions: 75% ethanol, extraction temperature
of 50 °C, ultrasonic power of 600W, extraction time of 3 min,
liquid-to-solid ratio of 30:1 (v/w), and systemic pressure of
25 kPa. After extraction, the extract was filtered. The ethanol
phase was then evaporated at 45 °C, and the water residue was
lyophilized for 48 h at −70 °C and 0.013 mbar using a vacuum
freeze drier (VirTisWizard 2.0, Gardiner, NY, USA). The extraction
was performed in triplicate.