Rotenone, is a biopesticide which can be isolated from Derris species roots. However, procuring significant amount of rotenone using green alternative solvent rather than harmful organic solvents for commercialization is a challenge to be faced. Therefore, an approach using imidazolium-based ionic liquids (ILs) as an extraction medium was employed in this study. Five different types of binary solvent systems comprising a combination of acetone and five respective ionic liquids (ILs) of (1) [BMIM] Cl; (2) [BMIM] OAc; (3) [BMIM] NTf2; (4) [BMIM] OTf; and (5) [BMPy] Cl were used in the normal soaking extraction (NSE) of rotenone for a 24-hour extraction. The yield of the rotenone, % (w/w), and its concentration (mg/mL) in the dried roots was quantitatively determined by means of the reversed-phase high-performance liquid chromatography (RP-HPLC) and thin-layer chromatography (TLC). The results showed that a binary solvent system of [BMIM] OTf:acetone was the best solvent system combination compared to other solvent systems (p < 0.05). It contributed to the highest rotenone content of 2.69 ± 0.21% (w/w) (4.04 ± 0.34 mg/ml) at the 14th hour of the exhaustive extraction time. In conclusion, a combination of certain ILs with a selective organic solvent has been proven to be able to increase a significant amount of bioactive constituents in the phytochemical extraction process.
Part of the book: Ionic Liquids