Increased Enantioselectivity and Remarkable Acceleration of Lipase‐Catalyzed Transesterification by Using an Imidazolium PEG—Alkyl Sulfate Ionic Liquid.

Abstract

Biochemical syntheses O 0035Increased Enantioselectivity and Remarkable Acceleration of Lipase-Catalyzed Transesterification by Using an Imidazolium PEG-Alkyl Sulfate Ionic Liquid.-A remarkable acceleration concerning the transesterification reaction of a variety of alcohols with vinyl acetate is accomplished by use of ionic liquid-coated lipase PS compared to the pure enzyme. It reaches approximately 500-to 1000-fold acceleration for some substrates with excellent enantioselectivities. The reaction of alcohol (IVc) in ionic liquid FIL can be performed 4 times by use of recycled IL-coated lipase PS with excellent enantioselectivity and without significant decrease of the reaction rate. Both enantioselectivity and reaction rate of the esterification of acid (VI) with butanol in the presence of IL-coated lipase (Candida rugosa) are also improved in comparison to the pure enzyme. -(ITOH*, T.; MATSUSHITA, Y.; ABE, Y.; HAN, S.-H.; WADA, S.; HAYASE, S.; KAWATSURA, M.; TAKAI, S.; MORIMOTO, M.; HIROSE, Y.; Chem. Eur. J. 12 (2006) 36, 9228-9237; Dep. Mater. Sci., Fac. Eng., Tottori Univ.,

On the nature of ionic liquids and their effects on lipases that catalyze ester synthesis

“…triolein) towards the enzyme, while the strong polar anion ([MS]) and the polyetoxy and free hydroxyl groups in the cation part dictate the selectivity of the enzyme. In the same way, Itoh et al (2006) described how the activity and enantioselectivity of immobilized Burkholderia cepacia lipase was greatly enhanced by coating the catalyst with ILs based on poly(oxyethylene)alkyl sulphate, a structure similar to the moiety of the [CPMA] cation.…”

“…In this context, lipases are the class of enzymes that have been most widely studied, because of the high level of activity and stereoselectivity displayed in synthesizing many different compounds, e.g. aspartame (Erbeldinger et al, 2000), aliphatic and aminoacid esters (Lozano et al, 2003), chiral esters by kinetic resolution of sec-alcohols (Schöfer et al, 2001;Itoh et al, 2003Itoh et al, , 2006Lozano et al, 2004;Abe et al, 2008), flavonoid derivatives (Katsoura et al, 2006), polymers (Kaar et al, 2003;Gorke et al, 2007), etc. Furthermore, water-immiscible ILs also have an important stabilizing effect on hydrolases (lipases, esterases, proteases, etc.)…”

Recyclable Stereoselective Catalysts

“…It was disclosed that this material accelerated the enzymatic resolution of about 500 -to 1000 -fold, maintaining excellent levels of enantioselectivity (up to 99% ee). Both stabilized enzymes were reused four times without loss of activity [167] .…”

Significance of anionic functional group in betaine-type metabolite analogs on the facilitation of enzyme reactions

“…As additives, polyols [4][5][6][7], amino acids [8][9][10], proteins [11], polymers [11] and ionic liquids [12][13][14][15] are shown to be of benefit. While at the same time, since those additives mutually interact, each concentration and composition of additives [12] or pre-organized operation between additives and enzymes [16] are sometimes obstacles in the use.…”