Optimizing the extraction process, analyzing the composition and biological activity of essential oil from Artemisia scoparia using enzyme-assisted steam distillation

Artemisia scoparia is widely used in traditional Chinese medicine, and its essential oil (EO) is used as antioxidant, antibacterial agent and herbicide. However, the EO extraction efficiency is low, and the yield was only 0.0517% by steam distillation. The aim of study was to improve the EO extraction efficiency and analyze the EO composition and biological activity using enzyme-assisted steam distillation (ESD). The results of the response surface methodology (Box-Behnken test) showed that the following factors were significant in this order: enzymatic hydrolysis temperature > liquid-solid ratio > pH. The yield of A. scoparia EO was 0.0880% under the optimal conditions of ESD (liquid-solid ratio = 5.2:1, enzymatic hydrolysis temperature = 44.2 degrees C, pH = 7.0, enzyme addition = 3%, enzymatic hydrolysis time = 5 h, distillation time = 3 h), which was 1.7 times higher than that of steamdistillation, and the greenness of extraction (complete E-factor, cEF) results showed that ESD (cEF = 7007) was lower than steam distillation method (cEF = 11,604). The results of GC-MS showed that A. scoparia EO contained a large amount of terpenoids compositions, including sesquiterpenes (64.36%), monoterpenes (5.76%), and diterpenes (15.69%). More importantly, in addition to antibacterial and antioxidant activities, A. scoparia EO has hypoglycemic and lipid lowering activities. This study demonstrated that ESD is an efficient and environmentally friendly method for EO extraction, and A. scoparia EO has strong biological activity with great potential in biomedicine.