70916-53-9Relevant academic research and scientific papers
Biobased catalyst in biorefinery processes: Sulphonated hydrothermal carbon for glycerol esterification
De La Calle, Carlos,Fraile, José M.,García-Bordejé, Enrique,Pires, Elísabet,Roldán, Laura
, p. 2897 - 2903 (2015/05/13)
Sulphonated hydrothermal carbon (SHTC), obtained from d-glucose by mild hydrothermal carbonisation and subsequent sulphonation with sulphuric acid, is able to catalyse the esterification of glycerol with different carboxylic acids, namely, acetic, butyric and caprylic acids. Product selectivity can be tuned by simply controlling the reaction conditions. On the one hand, SHTC provides one of the best selectivity towards monoacetins described up to now without the need for an excess of glycerol. On the other hand, excellent selectivity towards triacylglycerides (TAG) can be obtained, beyond those described with other solid catalysts, including well-known sulphonic resins. Recovery of the catalyst showed partial deactivation of the solid. The formation of sulphonate esters on the surface, confirmed by solid state NMR, was the cause of this behaviour. Acid treatment of the used catalyst, with subsequent hydrolysis of the surface sulphonate esters, allows SHTC to recover its activity. The higher selectivity towards mono- and triesters and its renewable origin makes SHTC an attractive catalyst in biorefinery processes.
Optical control of enzyme enantioselectivity in solid phase
Bautista-Barrufet, Antoni,Lopez-Gallego, Fernando,Rojas-Cervellera, Victor,Rovira, Carme,Pericas, Miquel A.,Guisan, Jose M.,Gorostiza, Pau
, p. 1004 - 1009 (2014/04/03)
A lipase was immobilized on transparent agarose microspheres and genetically engineered to specifically anchor photochromic molecules into its catalytic site. Several combinations of azobenzene and spiropyran groups were conjugated to cysteines introduced at different positions near the active center. Light modulated the catalytic properties of the resulting solid bioconjugates, and such modulation depended on both the nature of the photochromic compound and the anchoring position. Covalent anchoring of azobenzene derivatives to the residue 295 of the lipase 2 from Bacillus thermocathenolatus triggered lipase preference for the S isomer under UV light, whereas visible light promoted preference for the R isomer. Molecular dynamics simulations indicate that conjugating photochromic compounds into the catalytic cavity allows manipulating the steric hindrance and binding energy of the substrates, leading to an enantioselective molecular fit in certain cases. Using this approach, we report for the first time the control of enzyme properties using light in the solid phase.
A kinetic study of the lipase-catalyzed ethanolysis of two short-chain triradylglycerols: Alkylglycerols vs. triacylglycerols
Vazquez, Luis,Fernandez, Oscar,Blanco, Rosa M.,Senorans, F. Javier,Reglero, Guillermo,Torres, Carlos F.
experimental part, p. 101 - 106 (2010/11/04)
Lipase-catalyzed ethanolysis of two short-chain triradylglycerols, namely tributyrin and 2,3-dibutyroil-1-O-alkylglycerols, have been studied. Much faster rate of reaction for the ethanolysis of tributyrin than that of 2,3-dibutyroil-1-O-alkylglycerols was attained. A kinetic model for the rate of release of ethyl butyrate and for the inactivation of the lipase has been also studied. The parameter corresponding to the release of ethyl butyrate was one order of magnitude higher for ethanolysis of tributyrin than the corresponding of 2,3-dibutyroil-1-O-alkylglycerols.On the contrary, the stability of Novozym 435 during ethanolysis of 2,3-dibutyroil-1-O-alkylglycerols was higher than the corresponding of tributyrin.At the reaction conditions under study, both ethanolysis reactions take place with high selectivity and yield monoesterified alkylglycerols and sn-2 monobutyrin as the main acylglycerols in the reaction mixtures.
