Lipase green solvent

M. Onaka, Efficient lipase-catalyzed enantioselective acylation in an ionic liquid solvent system. In Ionic Liquids as Green Solvents, R. D. Rogers, K. R. Seddon, Eds., ACS Symposium Series Vol. 856, ACS Washington D.C., 2003, p 251. 

In biodiesel production, methanol and lipid reaction products are immiscible and form two phases at room conditions. This results in low reaction effidency and lipase deactivation. Hydrophobic solvents can minimize this effect, however, they are toxic and require a separation unit, which further increases the overall production cost Supercritical carbon dioxide (SC-COj) has frequently been used to replace organic solvents in various chemical processes. Due to its properties— including the easy and complete removal of the solvent, an ability to manipulate the physical properties of the solvent by simply changing the pressure or tanperature, nontoxidty, nonflammability, and enhancement of substrate mass transfer properties— it was suggested as a green solvent in biocatalyst reactions. A chemical feature of SC-COj is its low critical temperature (below the denaturation temperature of lipase). This feature combines the good solubility of nonpolar compounds, such as lipids, and makes SC-CO2 the perfect medium for biodiesel production. 

Lipase-catalysed ROP is usually carried out in bulk or in organic solvents like heptane, toluene, diisopropyl ether and 1,4-dioxane. Due to the growing awareness for environmental protection, researchers are paying increasing attention to green solvents , working with water, SCCO2 and ionic liquids. 

Green Solvent for Lipase-Catalyzed Polymerization and Degradation. .. 127... 

Lipase-Catalyzed Polyester Synthesis and Degradation in OthCT Green Solvents. 161... 

Room-temperature ionic liquids have received much attention as green designer solvents. We first demonstrated that ionic liquids acted as good medium for lipase-catalyzed production of polyesters. The polycondensation of diethyl adipate and 1,4-butanediol using lipase CA as catalyst efficiently proceeded in l-butyl-3-methylimidazolinium tetrafluoroborate or hexafluorophosphate under reduced pressure. The polymerization of diethyl sebacate and 1,4-butanediol in l-butyl-3-methylimidazolinium hexafluorophosphate took place even at room temperature in the presence of lipase BC. ... 

Fatty acids of sugars are potentially useful and fully green nonionic surfactants, but the lipase-mediated esterification of carbohydrates is hampered by the low solubility of carbohydrates in reaction media that support lipase catalysis in general. Because the monoacylated product (Figure 10.8) is more soluble in traditional solvents than is the starting compound, the former tends to undergo further acylation into a diester. In contrast, the CaLB-catalyzed esterification of glucose with vinyl acetate in the ionic liquid [EMIm][BF4] was completely selective. The reaction became much faster and somewhat less selective when conducted in... 

Kara P, Hanefeld U, Kanerva LT (2009) Immobilised burkholderia cepacia lipase in dry organic solvents and ionic liquids a comparison. Green Chem 11 250-256... 

Lozano P, Piamtongkam R, Kohns K, de Diego T, Vaultier M, Iborra JL (2007) Ionic liquids improve dtroneUyl ester synthesis catalyzed by immobilized Candida antarctica lipase B in solvent-free media. Green Chem 9 780-784... 

Fresh green vegetables should first be homogenized in 2-propanol to deactivate lipases, which otherwise might be activated by some organic solvents. The solids are further extracted with chloroform/2-prop-anol. The lipids in both extracts are combined. 

Reacting lipophilic substrates with hydrophilic compounds, as in the case of most transesteriflcation reactions, is one of the major difficulties in lipase-catalyzed reactions. Several parameters need to be considered to overcome this immiscibility problem. One commonly proposed strategy is the use of a nonaqueous medium. In this chapter, the advantages of using nonaqueous media in biochemical synthesis reactions, over aqueous and solvent-free systems, are discussed. The use of hydrophobic solvents is also discussed, followed by a presentation of the alternatives that can overcome the limitations of solvents. The focus of this chapter is mainly on the use of supercritical fluids (SCFs) as a green alternative reaction medium. The chapter also discusses ionic liquids (ILs) as another alternative. These solvents and the factors affecting their physical properties and their effect on the activity and stability of lipase are also discussed. 

Ionic liquids are often used as reaction solvent for the synthesis and modification of polymers due to their green character [76]. The first paper on ionic liquids as solvent for enzymatic polymerization appeared in 2002. Lipase-catalyzed ROP of e-CL and the polycondensation between diethyl adipate or sebacate and 1,4-butane diol were achieved in an ionic liquid such as l-butyl-3-methyl-imidazolium salts ([bmim] [PFs]). The ROP gave rise to PCL with of4,200 MJMn = 2.7) in 97% yields at 60°C after 7 days [77]. Lipase CA-catalyzed ROP of e-CL in three ionic liquids, [bmimliBFJ, [bmim][PF6], and [bmim][(CF3S02)2N], at 60°C for 24 h produced PCL with a higher of 7,000-9,500 2.4) in good yields. In... 

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