Influence of ionic liquid on Novozym 435-catalyzed the transesterification of castor oil and ethyl caffeate

Ionic Liquids in Metal, Photo-, Electro-, and (Bio) Catalysis

Ionic liquids (ILs) have unique physicochemical properties that make them advantageous for catalysis, such as low vapor pressure, non-flammability, high thermal and chemical stabilities, and the ability to enhance the activity and stability of (bio)catalysts. ILs can improve the efficiency, selectivity, and sustainability of bio(transformations) by acting as activators of enzymes, selectively dissolving substrates and products, and reducing toxicity. They can also be recycled and reused multiple times without losing their effectiveness. ILs based on imidazolium cation are preferred for structural organization aspects, with a semiorganized layer surrounding the catalyst. ILs act as a container, providing a confined space that allows modulation of electronic and geometric effects, miscibility of reactants and products, and residence time of species. ILs can stabilize ionic and radical species and control the catalytic activity of dynamic processes. Supported IL phase (SILP) derivatives and polymeric ILs (PILs) are good options for molecular engineering of greener catalytic processes. The major factors governing metal, photo-, electro-, and biocatalysts in ILs are discussed in detail based on the vast literature available over the past two and a half decades. Catalytic reactions, ranging from hydrogenation and cross-coupling to oxidations, promoted by homogeneous and heterogeneous catalysts in both single and multiphase conditions, are extensively reviewed and discussed considering the knowledge accumulated until now.

Enhancement of the hydrophilic feruloyl glycerol synthesis using A-35 as a catalyst and its functional characteristics

Feruloyl glycerol (FG) is the hydrophilic ester of ferulic acid (FA), which has a high solubility in water and a strong ability to resist ultraviolet (UV) radiation. In this work, several solid acids were used as novel economical catalysts and FA was used as a cheap substrate for FG preparation. The effects of reaction variables on the esterification of FA with glycerol were investigated and optimized by response surface methodology (RSM). Results showed that a cheap solid acid cation exchange resin A-35 showed the best performance for esterification. The reaction conditions were optimized by RSM as follows: 15 : 1 (glycerol/FA) substrate molar ratio and 14% catalyst loading at 90 °C for 7 h. The maximum FG yield (98.50 ± 0.58%) was achieved under the optimized conditions. The activation energy of the esterification was 53.71 kJ mol^-1. The results of UV absorbance showed that FG had good anti-UV activity and photostability, which can be used as a potential antioxidant and UV absorber in food and sunscreen products.

Green Technologies for the Production of Modified Lipids

In recent years, the use of green solvents in enzyme catalysis of lipophilic compounds is achieving increasing interest from different perspectives. Conducting reactions under supercritical fluids, ionic liquids, deep eutectic solvents, and other green solvents affords opportunities to overcome problems associated with the lack of solubility of lipids in conventional solvents and the poor miscibility of substrates. Research on the biocatalytic production of modified lipids in the framework of green chemistry is conducted to improve the efficiency of obtaining the desired products as well as the selectivity, stability, and activity of the enzymatic systems. This overview describes the fundamentals and characteristics of several types of green solvents, the main variables involved in enzymatic processes, and examples and applications in the field of lipid modification.