Lipase-catalyzed esterification of conjugated linoleic acid with l-carnitine in solvent-free system and acetonitrile

Abstract

Lipase-catalyzed esterification of conjugated linoleic acid (CLA) with L-carnitine in solvent-free system and acetonitrile was studied. Three lipases (Novzym 435, Amamo AY30 and Amano AYS) have been assayed as suitable biocatalysts in the reaction. It was found that Amano AY30 was the most effective biocatalyst in both solvent-free system and acetonitrile. The conversion rate varied from 8.05 to 60.9% in terms of reaction conditions such as the amount of lipase, the presence of water, the amount of molecular sieves and reaction time. The conversions of substrate in solvent-free system were higher than that in acetonitrile. When the substrates were 1 mmol CLA and 1 mmol L-carnitine, the maximum conversion (60.9%) was obtained in solvent-free system with 150 mg lipase AY30, 50% water content and 150 mg molecular sieves at the reaction time of 24 h. A novel CLA ester product was successfully isolated and characterized by ESI-MS and (1)H NMR.

Lipase-Catalyzed Esterification of Phloridzin: Acyl Donor Effect on Enzymatic Affinity and Antioxidant Properties of Esters

“…Acylation reactions can be performed in the presence of inorganic catalysts, but several studies reported that chemical esterification is not regioselective and results in unwanted functionalization of phenolic hydroxyl groups, which are responsible for antioxidant activity. On the other hand, lipases are widely recognized as suitable catalysts for obtaining various products due to their chemo-, regio-, and enantioselectivities, as well as low prices and availability. − In accordance with this, enzymatic acylation of flavonoids catalyzed by lipases (triacylglycerol acylhydrolase, EC 3.1.1.3) is an attractive alternative, since it is more regioselective than chemical acylation and may improve not only their solubility in various media, but also their stability and their antioxidant activity. , Also, using lipase as a catalyst allows the use of much milder reaction conditions and gives higher yields, better product quality, and lower downstream processing costs.…”

“…6−10 In accordance with this, enzymatic acylation of flavonoids catalyzed by lipases (triacylglycerol acylhydrolase, EC 3.1.1.3) is an attractive alternative, since it is more regioselective than chemical acylation and may improve not only their solubility in various media, but also their stability and their antioxidant activity. 5,11 Also, using lipase as a catalyst allows the use of much milder reaction conditions and gives higher yields, better product quality, and lower downstream processing costs. So far, to the authors' best knowledge, publications referring to phloridzil ester synthesis have been very rare.…”

Synthesis and Characterization of Phenolic Lipids

“…Li et al [111] reported that the addition of molecular sieves increased the rate and conversion yield; this is due to the efect of the molecular sieves to sequester the water layer from the enzyme molecule which is essential for the water-enzyme interaction. Mellou et al [112] found that the conversion yield of rutin during esteriication reaction with oleic acid catalyzed by immobilized C. antarctica lipase B in diferent solvents was varied from 37 to 71% under the use of molecular sieves (100 mg/ ml).…”