Synthesis of CLA-Rich Lysophosphatidylcholine by Immobilized MAS1-H108A-Catalyzed Esterification: Effects of the Parameters and Monitoring of the Reaction Process

Preparation of vacuum-assisted conjugated linoleic acid phospholipids under nitrogen: Mechanism of acyl migration of lysophospholipids

Sn-Glycerol-3-phosphatidylcholine (GPC) was prepared by hydrolysis of phosphatidylcholine (PC) catalyzed by phospholipase A1 (PLA1). Nitrogen flow assisted the esterification of conjugated linoleic acid (CLA) and GPC to produce conjugated linoleic acid lysophosphatidylcholine (LPC - CLA). The effects of different reaction conditions on the PC conversion and acyl migration rates were investigated, and the acyl migration mechanism under acidic and alkaline conditions was studied. In addition, the optimum conditions for the esterification of CLA and GPC were selected. The optimal condition for the hydrolysis of PC was an enzyme loading of 5 %, pH of 5, reaction temperature of 50 ℃, and reaction time of 3 h. The results also showed that the maximum esterification rate reached 82.37 % at an enzyme loading of 15 %, CLA/GPC molar ratio of 50:1, and vacuum pressure of 13.3 kPa. This study not only improved the bioavailability of PC but also effectively increased the content of LPC - CLA.

Properties of immobilized MAS1-H108A lipase and its application in the efficient synthesis of n-3 PUFA-rich triacylglycerols

This study reports the properties of immobilized MAS1-H108A lipase from marine Streptomyces sp. strain W007 on XAD1180 resin and its application in the synthesis of n-3 polyunsaturated fatty acids (PUFA)-rich triacylglycerols (TAG) for the first time. It was found that the optimal temperature and pH for both immobilized MAS1-H108A lipase and free lipase MAS1-H108A were 70 °C and 7.0, respectively. However, immobilized MAS1-H108A lipase exhibited higher thermostability when compared with free lipase MAS1-H108A. It was also interesting that both immobilized MAS1-H108A lipase and free lipase MAS1-H108A showed no regiospecificity in the hydrolysis of triolein. Subsequently, immobilized MAS1-H108A lipase and free lipase MAS1-H108A were employed to catalyze glycerolysis of n-3 PUFA-rich ethyl esters (EE) and esterification of n-3 PUFA with glycerol under vacuum in the solvent-free system. The results showed that n-3 PUFA-rich TAG were synthesized efficiently by non-regiospecific immobilized MAS1-H108A lipase and TAG contents separately reached 92.07% and 76.13% during the esterification and glycerolysis reactions, which were significantly higher than those (71.82% and 39.62%, respectively) obtained by free lipase MAS1-H108A. Besides, TAG exhibited similar n-3 PUFA composition to the substrate. These findings indicated that non-regiospecific immobilized MAS1-H108A lipase is a promising and efficient biocatalyst for the industrial synthesis of n-3 PUFA-rich TAG.

An Efficient Synthesis of Lysophosphatidylcholine Enriched with n-3 Polyunsaturated Fatty Acids by Immobilized MAS1 Lipase

n-3 polyunsaturated fatty acid (PUFA)-rich lysophosphatidylcholine (LPC) with many beneficial effects was effectively synthesized by immobilized MAS1 lipase-catalyzed esterification of n-3 PUFA with sn-glycero-3-phosphatidylcholine (GPC) under vacuum in a solvent-free system. Immobilized MAS1 lipase was found to be a more suitable catalyst for the production of n-3 PUFA-rich LPC when compared with Novozym 435. The maximal GPC conversion and LPC content (93.12% and 90.77 mol %) were obtained under the optimized conditions (enzyme loading of 300 U/g substrate, temperature of 55 °C, and n-3 PUFA/GPC molar ratio of 20:1). Moreover, it was observed that 1-acyl-sn-glycero-3-lysophosphatidylcholine (sn-1 acyl LPC) was the main reaction product, as demonstrated by molecular docking. These results showed that immobilized MAS1 lipase had high phospholipase activity with a predominant specificity for the sn-1 hydroxyl position of GPC to efficiently synthesize highly pure n-3 PUFA-rich LPC from GPC for industrial application.

Lipase Catalyzed Acidolysis for Efficient Synthesis of Phospholipids Enriched with Isomerically Pure cis-9,trans-11 and trans-10,cis-12 Conjugated Linoleic Acid

The production of phospholipid (PL) conjugates with biologically active compounds is nowadays an extensively employed approach. This type of phospholipids conjugates could improve bioavailability of many poorly absorbed active compounds such as isomers of conjugated linoleic acid (CLA), which exhibit versatile biological effects. The studies were carried out to elaborate an efficient enzymatic method for the synthesis of phospholipids with pure (>90%) cis-9,trans-11 and trans-10,cis-12 CLA isomers. For this purpose, three commercially available immobilized lipases were examined in respect to specificity towards CLA isomers in acidolysis of egg-yolk phosphatidylcholine (PC). Different incorporation rates were observed for the individual CLA isomers. Under optimal conditions: PC/CLA molar ratio 1:6; Rhizomucor miehei lipase loading 24% wt. based on substrates; heptane; DMF, 5% (v/v); water activity (aw), 0.11; 45 °C; magnetic stirring, 300 rpm; 48 h., effective incorporation (EINC) of CLA isomers into PC reached ca. 50%. The EINC of CLA isomers was elevated for 25–30% only by adding a water mimic (DMF) and reducing aw to 0.11 comparing to the reaction system performed at aw = 0.23. The developed method of phosphatidylcholine acidolysis is the first described in the literature dealing with isometrically pure CLA and allow to obtain very high effective incorporation.

Novozym 435: the “perfect” lipase immobilized biocatalyst?

Novozym 435 (N435) is a commercially available immobilized lipase produced by Novozymes with its advantages and drawbacks.