Biocatalysis supercritical carbon dioxide

Another environmental issue is the use of organic solvents. The use of chlorinated hydrocarbons, for example, has been severely curtailed. In fact, so many of the solvents favored by organic chemists are now on the black list that the whole question of solvents requires rethinking. The best solvent is no solvent, and if a solvent (diluent) is needed, then water has a lot to recommend it. This provides a golden opportunity for biocatalysis, since the replacement of classic chemical methods in organic solvents by enzymatic procedures in water at ambient temperature and pressure can provide substantial environmental and economic benefits. Similarly, there is a marked trend toward the application of organometal-lic catalysis in aqueous biphasic systems and other nonconventional media, such as fluorous biphasic, supercritical carbon dioxide and ionic liquids. ... 

Knez, Z. Habulin, M. Lipase Catalyzed Esterification in Supercritical Carbon Dioxide. In Biocatalysis in Non-Conventional Media Tramper, J., Vermiie, M. H., Beeftink, H. H., Eds. Elsevier Science Amsterdam, 1992, pp. 401-406. Knez, Z. Habulin, M. Krmelj, V. Enzyme Catalyzed Reactions in Dense Gases. J. Supercrit. Fluids 1998, 14, 17-29. 

Supercritical fluids (SCFs) and in particular supercritical carbon dioxide (scC02) have also been shown to provide a unique medium in which to perform biocatalytic transformations. The ability to perform biocatalysis in a supercritical fluid was first demonstrated in 1985 by several groups. There are several advantages to the use of SCFs, as well as some drawbacks that need to be addressed if large-scale processes are to be developed. 

Reetz, M.T., Wiesenhoefer, W., Francio, G., and Leitner, W., Biocatalysis in ionic liquids batchwise and continuous flow processes using supercritical carbon dioxide as the mobile phase, Chem. Commun. 992-993 (2002). 

Many enzymatic processes can be of practical value, if they are carried out in anhydrous media instead of water. While biocatalysis in organic solvents is well established, the use of supercritical fluids, in particular supercritical carbon dioxide (SC-CO2), is still restricted to research on laboratory scale. 

D. Combes, Enzymatic Reactions in Supercritical Carbon Dioxide, in R. N Patel (Ed.), Stereoselective Biocatalysis, Marcel Dekker, New York, Basel,... 

Knez, Z., and Habulin, M. (1992) Lipase-catalyzed esterification in supercritical carbon dioxide. Prog. Biotechnol., 8, (Biocatalysis in Non-Conventional Media), 401-406. 

A biocatalytic carbon dioxide fixation reaction was conducted in supercritical carbon dioxide for the first time. It will play a significant role both in identifying enzyme species suitable for biocatalysis in supercritical carbon dioxide and in developing synthetic methods using carbon dioxide. 

Gremos S,Kekos D,Kolisis F. Supercritical carbon dioxide biocatalysis as a novel and green methodology for the enzymatic acylation of fibrous cellulose in one step. BioresourTechnol 2012 115 96-101. 

H.R. Hobbs, H.M. Kirke, M. Poliakoff, N.R. Thomas, Homogeneous biocatalysis in both fluorous biphasic and supercritical carbon dioxide systems, Angew. Chem. Int. Ed. 46 (2007) 7860-7863. 

Very recently, CPO was assessed in an enantioselective cascade oxidation using a biphasic media composed of supercritical carbon dioxide/water." Herein, the enzymatic sulfoxidation was carried out by generating hydrogen peroxide via Pd(0)-catalyzed formation from hydrogen and oxygen (in SCCO2) (Scheme 36.30). Overall, this example represents an outstanding case on how biocatalysis can be applied under different nonconventional reaction media, as... 

A Marty, JS Gondoret, D Combes. Fatty acid esterification in supercritical carbon dioxide. In Tramper et al., eds. Biocatalysis in Nonconventional Media, Vol. 8. New York, Elsevier, 1992, pp 425-432. 

Chapters are also included on yeast-mediated stereoselective biocatalysis, stereoselective synthesis of steroids, chemo-enzymatic synthesis of enantiopure arylpropionic acids, supercritical carbon dioxide as a solvent in enzyme catalysis, state-of-the-art techniques in enzyme immobilization, biocatalysis by polyethylene glycol-modified enzymes, and enzymatic deprotection techniques in organic synthesis. 

Lamare S, Legoy M (1993) Biocatalysis in the gas phase. TIBTECH 11 413 18 Laudani CG, Habulin M, Knez 2 et al. (2007) Lipase-catalyzed long chtiin fatty ester synthesis in dense carbon dioxide kinetics and thermodynamics. J Supercritical Fluids 41 92-101 Lauwers A, Scharpe S (1997) Pharmaceutical enzymes. Marcel Dekker, New York, 401 pp Laval JM, Thomas D, Mazeran PE (2000) Nanobiotechnology and its role in the development of new analytical devices. Analyst 125 29-3... 

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