Enzymatic synthesis of glyceride esters in solvent-free system: influence of the molar ratio, lipase source and functional activating agent of the support

Abstract

Este trabalho avaliou a influência de fatores que afetam a síntese de ésteres glicéricos, tais como: razão molar entre os reagentes, fonte de lipase e tipo de agente de ativação do suporte obtido pela técnica sol-gel. Foram empregadas preparações comerciais de lipases imobilizadas em partículas de polissiloxano-álcool polivinílico (POS-PVA) previamente ativadas com diferentes agentes (glutaraldeído, metaperiodato de sódio e carbonildiimidazol). Esses resultados foram comparados com aqueles obtidos por preparações de lipase imobilizada disponíveis comercialmente (Lipozyme IM 20 , Novozym 435, Lipozyme RM IM e Lipozyme TL IM). O meio reacional contendo excesso de glicerol favoreceu a síntese de ésteres glicéricos e a Lipozyme IM 20 foi a preparação de lipase imobilizada mais adequada para a síntese, atingindo conversões molares maiores que 94%. O uso da lipase CALB L imobilizada em POS-PVA também alcançou resultados satisfatórios (cerca de 80% de conversão) possibilitando a formação de 36% de 2,3-diidroxipropil dodecanoato (monolaurina).This work assessed the influence of important factors that affect the synthesis of glyceride esters in solvent-free systems, such as: glycerol/fatty acid molar ratio, lipase source and activating agent of the support obtained by the sol-gel technique. Commercial lipase preparations were immobilized on polysiloxane-polyvinyl alcohol particles (POS-PVA) previously activated with different agents (glutaraldehyde, sodium metaperiodate and carbonyldiimidazole) and their performance on the esterification reaction was compared with commercial preparations of immobilized lipase (Lipozyme IM 20 , Novozym 435, Lipozyme RM IM and Lipozyme TL IM). The reaction medium containing excess glycerol favored the glyceride ester synthesis and the Lipozyme IM 20 was found to be the most suitable immobilized lipase preparation, attaining molar conversions higher than 94%. The use of CAL B Lipase immobilized on POS-PVA also provided satisfactory performance (conversion of about 80%) and allowed the formation of 36% wt of 2,3-dihydroxypropyl dodecanoate (monolaurin).Keywords: glycerides, lipase, esterification, hybrid support, immobilization IntroductionThe demand of the industries to operate their processes under sustained conditions such as green chemistry or clean technology systems is becoming an important issue nowadays and thus requests the availability of tailored biocatalysts to operate under these conditions. 1 Therefore, the need for developing active and stable immobilized biocatalysts for subsequent use in biotransformations has been highlighted. 2 Among the most important biocatalysts carrying out novel reactions in both aqueous and non aqueous media, lipases stand out due to their ability to utilize a wide spectrum of substrates, high stability towards extremes of temperature, pH and organic solvents, and chemo-, regio-and enantioselectivity. [3][4][5] Although most enzymatic syntheses are performed in presence of organic non-polar solvents, 6 the elimination of these compounds is technicall...

Optimization of oligoglycerol fatty acid esters preparation catalyzed by Lipozyme 435

“…However, as Lipozyme 435 is a type of immobilized lipase that already has a certain content of water, and it can maintain activity without the addition of extra water (Zhong et al, 2013). On the contrary, the addition of extra water reduced the enzyme concentration and affected the hydration of the enzyme directly, or indirectly, by changing the nature of lipase support materials (Freitas et al, 2007), which resulted in a decrease in enzyme activity. On the other hand, esterification is the reverse reaction of hydrolysis.…”

Progress in Synthesis of Monoglycerides for Use in Food and Pharmaceuticals

“…When the production of a high degree pure monoglyceride is desired, lipase-catalyzed esterification is the appropriate route. Lipase-catalyzed synthesis of these partial glycerols by the direct esterification of glycerol with fatty acids in different reaction media have been studied and concluded that aqueous-organic two-phase systems [25], microemulsions [26,27] and anhydrous organic solvents [27] as well as the use of solvent-free systems are the best selections [28,29]. Apart from solvent system, proper selection of lipase also contributes to success of the method.…”

Otimização da esterificação de ácido hexanóico com n-butanol empregando lipase (Termomyces lanuginosus) imobilizada em gelatina

“…3.1.1.3) provenientes do fungo Thermomyces lanuginosus, comercializadas sob a denominação de Lipozyme TL, tem sido citada em diversos trabalhos relacionados à obtenção de ésteres. 1,2,[6][7][8][9][10][11][12][13] Na sua forma imobilizada, estas enzimas são mais estáveis no meio orgânico, facilitando sua recuperação e posterior reutilização. 8 Dessa forma, ainda existe um grande campo de estudos a ser explorado, relacionado à síntese enzimática de ésteres em sistemas que empreguem materiais de baixo custo como suportes, gerando resultados que permitam avaliar a viabilidade técnica econômica da produção desses compostos.…”