Effect of different factors to the extraction yield of paclitaxel in the single factor experiments. (a) the IL amount (0.5 g T. x media leaves powder, 60 vol % methanol, 1:10 solid–liquid ratio, 40 °C extraction temperature, and 30 min extraction time); (b) Methanol concentration (0.5 g T. x media leaves powder, 1.0 wt % IL, 1:10 solid–liquid ratio, 40 °C extraction temperature, and 30 min ultrasonic irradiation time); (c) Solid–liquid ratio (0.5 g T. x media leaves powder, 60 vol % methanol, 1.0 wt % IL, 40 °C extraction temperature, and 30 min ultrasonic irradiation time); (d) Extraction temperature (0.5 g T. x media leaves powder, 60 vol % methanol, 1.0 wt % IL, 1:10 solid–liquid ratio, and 30 min ultrasonic irradiation time); (e) Ultrasonic irradiation time (T. x media leaves powder, 60 vol % methanol, 1.0 wt % IL, 1:10 solid–liquid ratio, and 40 °C extraction temperature). Different letters in the same series indicate significant difference at p < 0.05 level.