“Green” Alternatives to Conventional Organic Solvent: A Closer Look at the Screening of Room Temperature Ionic Liquids (RTILs) for the Biosynthesis of Lipophilic Flavonoid Esters
Special Symposium - Innovations in Food Technology (LMC Congress)
Innovations in Food Technology - Poster Session (LMC/Food - P1)
Keywords: room temperature ionic liquids (RTILs), flavonoids, screening, lipase, biocatalysis
Room temperature ionic liquids (RTILs) are often referred to as solvents of the future and are regarded as promising replacements for traditional organic solvents due largely to their lack of vapour pressure. Besides not releasing organic volatiles into the air, they are regarded as possible substitutes in enzyme biocatalysis for many other reasons, including their high thermal stability, wide liquid range and their potential for solubility modifications (i.e. through appropriate cation & anion selection).
The modification of flavonoids into their fatty acid esters alters physico-chemical properties and increases their potential in human nutrition. Due to differences in solubilities of flavonoids and fatty acids, the development of an efficient enzymatic system for the acylation of flavonoids in organic solvent media is problematic. Butanol, pentanol & acetone remain among the more efficient conventional solvents used to date for these reactions. In this work, a range of ionic liquids (ILs) were screened for use in the biosynthesis of fatty acid esters of the flavonoids rutin and esculin.
The ILs investigated were composed of a range of cation moieties such as imidazolium, pyridinium and tetraammonium while common anion moieties included structures such as Cl-, BF4-, PF6-, trifluoroacetate, alkylsulfates and sulfonates. ILs were screened in order to determine which structures maintained maximal lipase activity in the reaction system of interest. Overall, it was apparent that not all ILs were appropriate for this type of reaction system. However, based on this screening, it was possible to elucidate further as to the type of structure compatible with the maintenance of enzymatic activity. Lastly, experimental results could also be compared with initial predictions made using the COSMO-RS (Conductor-like Screening Model for Real Solvents) quantum chemical model.
Presented Wednesday 19, 13:30 to 15:00, in session Innovations in Food Technology - Poster Session (LMC/Food - P1).
