Modulating Biocatalytic Activity toward Sterically Bulky Substrates in CO₂-Expanded Biobased Liquids by Tuning the Physicochemical Properties

Abstract

The study of CO 2-expanded liquids using a green component such as a biobased solvent has been recently raised as a new concept for an alternative solvent and yet been largely unexplored in the literature for neither fundamental nor application studies. On the other hand, structural bulkiness of substrates remains one of the main limitations to promote enzymes as an efficient versatile catalytic tool for organic synthesis, especially biocatalysis in nonconventional solvents. Herein, we report a detailed investigation of CO 2-expanded biobased liquids as reaction media for improved biocatalysis of sterically hindered compounds. We found that CO 2 acts as a crucial trigger for various lipases to catalyze transesterification of challenging bulky alcohols in CO 2-expanded 2-methyltetrahydrofuran (MeTHF). Furthermore, this study determines the physicochemical and transport properties of CO 2-expanded MeTHF for the first time, which were then utilized for modulating biocatalytic activity. It was found that lipase activity increased with the accordingly decrease of the dipolarity of CO 2-expanded MeTHF, which is tunable by altering the concentration of CO 2 in the solvent system.

CO2-Expanded Alkyl Acetates: Physicochemical and Molecular Modeling Study and Applications in Chemical Processes

“…The phase equilibria and polarity measurements were performed by using the experimental equipment used in our previous studies. 21 Briefly, a high-pressure variable-volume view cell (9.6-31.3 cm 3 , Top Industrie, France) equipped with three sapphire windows and a magnetic stirrer ( Figure 1) and a 260D high-pressure Teledyne Isco syringe pump (the precision of the injected volume is ±1 cm 3 ). The temperature of the cell was kept at the desired value by a thermostatic bath and measured by a thermocouple (J type, precision of ±0.1 K) placed inside of the cell.…”

Ternary System CO2/2-MTHF/Water—Experimental Study and Thermodynamic Modeling

“…The higher solubility of CO 2 in 2-MTHF relative to that in water can be explained by a comparison of the Kamlet−Taft values (π*) for both solvents. 55 Hoang et al 54 With a consideration of the quadrupole moment in P4/P6, the binary subsystem CO 2 /2-MTHF can be described solely on the basis of pure chemical species parameters within our reported uncertainty. We attempted to model binary system CO 2 /2-MTHF with Aspen PC-SAFT based on pure chemical species parameters only.…”

“…Solubility data for CO 2 in the liquid phase of binary system CO 2 /2-MTHF at 293 K. Experimental data from the present work (▲) and from ref (△). Calculated values from the P4/P6 model () and with adjusted value for k ij in the A6 model (blue −–−).…”

“…A linear trend for the mole fraction of CO 2 in 2-MTHF as the pressure increases is shown in Figure 4 for the evaluated pressure range. Hoang et al measured the solubility of CO 2 in 2-MTHF using a visual method 54 and found a linear pressure dependency. Their data is in good agreement with the data measured in this work (Figure 4).…”

Integrated and Metal Free Synthesis of Dimethyl Carbonate and Glycidol from Glycerol Derived 1,3-Dichloro-2-propanol via CO2 Capture

“…Hence, the use of 2-Me-THF in the synthesis not only facilitated the sepa- reported that 2-Me-THF has a higher CO 2 solubility in the reaction system than water under identical experimental conditions [23]. Jessop and Matsuda et al showed that 2-Me-THF has lower values of Kamlet-Taft parameters such as polarizability, π* (0.5-1.1), which further allowed for the higher solubility of hydrophobic CO 2 in 2-Me-THF than water [24,25]. Matsuda et al also further reported that CO 2 expanded 2-Me-THF, and other bio-based solvents turned out to be an excellent solvent media for biotransformation.…”