Ionic liquid technologies for valuable ingredient isolation from biomass

Abstract

The present work focuses on alternative extraction or isolation processes of valuable ingredients from biomaterials using novel ionic liquid-based technologies. In the first part of this thesis a set of ionic liquids, including protic, hydrophilic, biodegradable and surface-active species was successfully synthesized and characterized. Tailor-made ionic liquids were further applied for different extraction/isolation problems by dissolution of various kinds of biomass. The valuable ingredient piperine that was extracted from black pepper using aqueous solutions of surface-active ionic liquids. Compared to pure water extraction yields were tremendously increased. A simple scale-up strategy was developed allowing the recovery of the ionic liquid solution for several times without any loss of efficiency. The use of ionic liquid-based micellar solutions was expanded to the isolation of eugenol from cloves. Again, those systems were suitable for the enhanced extraction of the active ingredient compared to aqueous systems. However the combination of extraction and an in situ derivatization towards isoeugenol in micellar systems was not possible so far. For the isolation of betulin birch bark was dissolved in hydrophilic ionic liquids. After the formation of a two-phase system via the addition of water and an environmentally benign organic solvent betulin was successfully isolated in enhanced yields in short time at room temperature. In this case, the in situ functionalization of the crude extract was possible, allowing to directly convert betulin to the value-added betulinic acid in high yields. Ionic liquids were also investigated for the in situ extraction and biocatalytic transformation of limonene from orange peels towards a valuable chiral polymer building block. Some ionic liquids were compatible with two different bacterial strains and biocatalysis was successfully performed in the presence of ionic liquids. However the combined extraction and conversion is still under investigations. In the last part of this thesis a simple, fast and efficient strategy based on an ionic liquid/buffer system was developed for a rapid determination of genetically modified maize via the extraction of DNA and analysis with qPCR. The developed method was superior to conventional systems, since not only time, but also costs were saved by reducing heating and centrifugation steps while isolating a comparable amount of DNA. The versatility of this method was further demonstrated by expanding ionic liquid/buffer systems to different meats. In summary a suitable ionic liquid was found for every extraction or isolation problem for valuable ingredients derived from a variety of different types of biomass.