Enzymatic esterification of glycerol II. Lipase‐catalyzed synthesis of regioisomerically pure 1(3)‐rac‐monoacylglycerols

Abstract

Regioisomerically pure 1(3)‐rac‐monoacylglycerols are conveniently prepared in high yields (>75%) and in multigram quantities by enzymatic esterification of glycerol in the presence of various lipases(Chromobacterium viscosum, Rhizopus delemar, Rhizomucor miehei) with a variety of different acyl donors, such as free fatty acids, fatty acid alkyl esters, vinyl esters and triacylglycerols, as well as natural fats and oils. All reactions are carried out in aprotic organic solvents with low water content, namelyn‐hexane, diethyl ether, tBuOMe or mixtures of these solvents. Essential for the success of these transformations were the following two factors. First, the creation of an artificial interphase between the solvent‐immiscible hydrophilic glycerol and the hydrophobic reaction medium by its adsorption onto a solid support. Second, a facile system for the separation of the desired monoacylglycerol from the reaction mixture, coupled with the continuous recycling of acyl donor and undesirable by‐products.

Synthesis of Either Mono-or Diacylglycerol from High-Oleic Sunflower Oil by Lipase-Catalyzed Glycerolysis.

“…To prevent the generation of dark-colored by-products with undesirable fiavors, Iow-temperature MAG synthesis using lipase has been attempted by many researchers. There are two main enzymatic pathways to yield MAG; ester synthesis from free fatty acid and glycerol (Tsujisaka et al, 1977;Hoq et al, 1984;Schuch & Mukherjee, 1989;Akoh et al, 1992;van der Padt et al, 1992;Berger & Schneider, 1992b;Li & Ward, 1993), and glycerolysis ofedible fats and oils (Yamane et al, 1986~, b;Holmberg et al, 1989;Yang et al, 1994a, b).…”

¹⁹F NMR method for the determination of quality of virgin olive oil

“…The deriving reagent (4-fluorobenzoyl chloride) (98%) and 4-tert-butylphenol were purchased from SigmaAldrich (SHH, CHN). 1,3-Stearin (DG) was synthesized from glycerol and stearic acid catalyzed by Lipozyme RM IM in the laboratory according to the method used by Berger et al (1992). 1,2-Stearin was made available from the partial hydrolysis of triglycerides through pancreatic lipase and separation of the formed mono-and diglycerides using thin-layer chromatography (IUPAC, 1987).…”

Monoglicerídeos: produção por via enzimática e algumas aplicações

“…Por outro lado, lipases de Geotrichum candidum e Penicillium cyclopium esterificaram somente ácidos graxos de cadeia longa e a esterificação ocorreu randomicamente. 60 Janssen et al 60 34 Desta forma, para obter rendimentos mais elevados, os autores desenvolveram um sistema de separação contínua constituída de 2 etapas: síntese e isolamento. Substratos não reagidos e subprodutos indesejados, tais como 2-MAG, DAG e TAG, foram completamente reciclados e 1(3) MAG foi congelado a baixas temperaturas.…”

“…Lipases não específicas também foram utilizadas com sucesso neste procedimento. 34 Berger e Schneider 34 demonstraram ainda que este método teve aplicabilidade para diferentes sistemas de esterificação usando vários doadores do grupo acila, tais como, ácidos graxos livres (C 5 a C 18 saturados ou insaturados), ésteres metílicos de ácidos graxos, ésteres vinílicos, triacilgliceróis sintéticos e óleos e gorduras naturais. Vários MAGs foram produzidos com elevado rendimento e pureza isomérica sem a necessidade de etapas posteriores de purificação.…”