Ionic liquid-coated immobilized lipase for the synthesis of methylglucose fatty acid esters

Abstract

A homologous series of biosurfactants has been synthesized by a novel sustainable biotransformation technique and compared with three other enzymatic processes. 6-O-Alkanoyl-methyl-a-D-glucopyranosides were obtained by lipase mediated esterification of methyl-a-D-glucopyranoside with capric acid C 10:0 , lauric acid C 12:0 , myristic acid C 14:0 , palmitic acid C 16:0 , and oleic acid C 18:1 . Solvent free transformations were compared with the use of ionic liquids and organic solvents. The lipase from Candida antarctica B, immobilized on macroporous acrylic acid beads (Novozyme 435), was employed either untreated or coated with small amounts of ionic liquids. This resulted in superior efficiencies (80%) with 1-butyl-4-methylpyridine hexafluorophosphate [4bmpy][PF 6 ] and broader substrate tolerance in comparison to solvent free transformation. The results show a positive correlation with increasing polarity of the ionic liquids used as liquid film-coating, which was in opposition to the use of the same ionic liquid as solvent. The analysis of the ionic liquid film coated catalyst carriers was performed by optical and scanning electron microscopy (SEM).

How ionic liquids can help to stabilize native proteins

“…Some studies have yielded reasonable correlations, 71,72 but in view of the multi-facetted molecular interactions it is fair to say that a general correlation cannot be expected.…”

Enzyme catalysis with small ionic liquid quantities

“…The esterification of a-methylglucoside with the fatty acids mediated by ionic liquid coated Novozyme 435 was *4.5 times more efficient than solvent-free transformations (Scheme 3). The C 10 and C 18:1 fatty acids were also converted, which was not the case with untreated Novozyme 435 under solvent-free conditions [22]. The most interesting observation was that the higher the polarity of the ionic liquid used as coating, the more productive the transformations (Fig.…”

“…After the process the scCO 2 is easily removed from reaction 6 ], match closely the capacity of the best organic solvents. This was shown in a solvent polarity trend study with myristic acid [22]. The ionic liquid coating leads to a pseudo-solvent-free reaction [2].…”

“…This process is actually a multiphase transformation and the mixture has typically a sludge-like appearance (Scheme 3, Fig. 3) [22]. In this transformation the condensing water was removed by molecular sieves.…”

Enzymatic Hydrolytic Resolution of Racemic Ibuprofen Ethyl Ester Using an Ionic Liquid as Cosolvent

“…Besides acting as a reaction media, ILs can also be used to pre-treat enzyme. There are many literature data on enhanced the activity and stability of enzyme by coating it with ILs which had been used for transesterification, esterification and hydrolysis reaction with higher enantioselecticity and yields [12,18].…”