Ionic liquids as green solvent and their applications in bioactive compounds extraction from plants

Abstract

The unfavourable impacts of organic solvents on the environmental and human health have increasingly drawn the attention of scientists and technologists for a long run solution. Recently, ionic liquids (ILs) have emerged as an environmentally friendly alternative of choice to reduce the use of organic solvents. This review covers the data of literature published from 2011 to 2021. Literature search was performed for the relevant journal articles including books, and book chapters using the keywords of ‘ionic liquid’, ‘extraction’, ‘medicinal plants’, ‘essential oil’, ‘waste water treatment’, ‘green extraction technology’ and combination of them. ILs are designer solvents due to their modifiable properties according to the application conditions. Therefore, this review highlights the application of ILs in the extraction and purification of bioactive compounds (glycosides, phenolic compounds, flavonoids, alkaloids and others) and essential oils from plant materials. This includes the use of ILs in the microwave and ultrasound assisted extractions, as well as solid phase extraction. Previous studies reported about 20–35 % of increment in the yield of bioactive compounds with the use of ILs.