Enzymatic hydrolysis of penicillin and in situ product separation in thermally induced reversible phase-separation of ionic liquids/water mixture

Ionic Liquid Aqueous Two-Phase Systems From a Pharmaceutical Perspective

Aqueous Two-Phase Systems (ATPSs) have been extensively studied for their ability to simultaneously separate and purify active pharmaceutical ingredients (APIs) and key intermediates with high yields and high purity. Depending on the ATPS composition, it can be adapted for the separation and purification of cells, nucleic acids, proteins, antibodies, and small molecules. This method has been shown to be scalable, allowing it to be used in the milliliter scale for early drug development to thousands of liters in manufacture for commercial supply. The benefits of ATPS in pharmaceutical separations is increasingly being recognized and investigated by larger pharmaceutical companies. ATPSs use identical instrumentation and similar methodology, therefore a change from traditional methods has a theoretical low barrier of adoption. The cost of typical components used to form an ATPS at large scale, particularly that of polymer-polymer systems, is the primary challenge to widespread use across industry. However, there are a few polymer-salt examples where the increase in yield at commercial scale justifies the cost of using ATPSs for macromolecule purification. More recently, Ionic Liquids (ILs) have been used for ATPS separations that is more sustainable as a solvent, and more economical than polymers often used in ATPSs for small molecule applications. Such IL-ATPSs still retain much of the attractive characteristics such as customizable chemical and physical properties, stability, safety, and most importantly, can provide higher yield separations of organic compounds, and efficient solvent recycling to lower financial and environmental costs of large scale manufacturing.

Recent developments in biocatalysis in multiphasic ionic liquid reaction systems

Ionic liquids are well known and frequently used 'designer solvents' for biocatalytic reactions. This review highlights recent achievements in the field of multiphasic ionic liquid-based reaction concepts. It covers classical biphasic systems including supported ionic liquid phases, thermo-regulated multi-component solvent systems (TMS) and polymerized ionic liquids. These powerful concepts combine unique reaction conditions with a high potential for future applications on a laboratory and industrial scale. The presence of a multiphasic system simplifies downstream processing due to the distribution of the catalyst and reactants in different phases.

Crystallographic Investigation of Imidazolium Ionic Liquid Effects on Enzyme Structure

We present the first crystallographic insight into the interactions of an ionic liquid (IL) with an enzyme, which has widespread implications for stabilizing enzymes in IL media for biocatalysis. Structures of Bacillus subtilis lipase A (lipA) and an IL-stable variant (QM-lipA) were obtained in the presence of increasing concentrations of 1-butyl-3-methylimidazolium chloride ([BMIM][Cl]). These studies revealed that the [BMIM] cation interacts with surface residues through hydrophobic and cation-π interactions. Of specific interest was the disruption of internal stacking interactions of aromatic side chains by [BMIM], which provides structural evidence for the mechanism of enzyme denaturation by ILs. The interaction of [BMIM] and Cl ions with lipA was reduced by the stabilizing mutations Y49E and G158E in QM-lipA. Ultimately, these findings present the molecular basis for stabilizing enzymes from IL-induced inactivation, as well as the selection of ILs that are less denaturing.

Thermoresponsive polyelectrolytes derived from ionic liquids

In this review we summarise recent progress on the design, properties, and potential applications of ionic liquid-derived polyelectrolytes showing thermoresponsive phase behaviour after mixing with water or other organic solvents.