Supercritical fluid extraction of dandelion leaves

β-Amyrin and β-sitosterol were extracted from dandelion in preparative scale using supercritical carbon dioxide. A 32 full-factorial design was carried out to map the effects of extraction pressure and temperature (over the ranges 150–450 bar and 35–65 °C, respectively) on the yields and recoveries of the active components. The supercritical fluid extraction (SFE) was compared to Soxhlet extraction with n-hexane and ethyl alcohol. The triterpene components were quantified by TLC-densitometry. The results demonstrated that SFE is an effective and selective method for recovery of β-amyrin and β-sitosterol. Soxhlet extraction with n-hexane gave yield and recoveries of the active components similar to the SFE. Among the investigated methods extraction with ethyl alcohol resulted the highest extraction yield and yields of β-amyrin and β-sitosterol. However, alcohol extracted unwanted components too, hence the concentrations of the triterpene compounds in the extract were very low.