Diacylglycerol(DAG)is a functional oil that can reduce body fat accumulation and postprandial triglycerides.In this study,lipase-catalyzed esterification of oleic acid with glycerol was investigated to elucidate the k...Diacylglycerol(DAG)is a functional oil that can reduce body fat accumulation and postprandial triglycerides.In this study,lipase-catalyzed esterification of oleic acid with glycerol was investigated to elucidate the kinetics and selectivity of each reaction step.1H NMR monitoring revealed equilibrated positional isomerization among acylglycerols:sn-1 monoolein comprised 97.3%of total monoacylglycerols,and sn-1,3 diolein comprised 73.3%of total diacylglycerols.Acyl migration(isomer equilibration)occurred faster than overall esterification.The observed rate constants for successive esterification steps(glycerol→monoacylglycerol,monoacylglycerol→diacylglycerol,diacylglycerol→triacylglycerol)were 0.01068,0.00615,and 0.00304 min^(-1),respectively,indicating progressively slower reaction rates for larger acylglycerol species.Furthermore,molecular distillation at 200–220℃ purified the DAG without altering its fatty acid profile.These findings establish a kinetic model of the three-step esterification and highlight the importance of acyl migration in enzymatic DAG synthesis.展开更多
The optically active R-4-phenyl-2-hydroxy butyrates were prepared by esterification of the racemic acid or transesterification of the racemic ester catalyzed by lipase from Candida cyclindra (CCL) in organic media.
基金Bureau of Science and Information of Guangzhou under grant 2024A04J3254the National Key Research and Development Program of China under grant 2024YFE0214900+2 种基金the National Natural Science Foundation of China under grant 32272341,he National Key Research and Development Program of China under grant 2023YFD2100401the Opening Project of Hubei Key Laboratory of Lipid Chemistry and Nutrition under grant 202401,are gratefully acknowledged.
文摘Diacylglycerol(DAG)is a functional oil that can reduce body fat accumulation and postprandial triglycerides.In this study,lipase-catalyzed esterification of oleic acid with glycerol was investigated to elucidate the kinetics and selectivity of each reaction step.1H NMR monitoring revealed equilibrated positional isomerization among acylglycerols:sn-1 monoolein comprised 97.3%of total monoacylglycerols,and sn-1,3 diolein comprised 73.3%of total diacylglycerols.Acyl migration(isomer equilibration)occurred faster than overall esterification.The observed rate constants for successive esterification steps(glycerol→monoacylglycerol,monoacylglycerol→diacylglycerol,diacylglycerol→triacylglycerol)were 0.01068,0.00615,and 0.00304 min^(-1),respectively,indicating progressively slower reaction rates for larger acylglycerol species.Furthermore,molecular distillation at 200–220℃ purified the DAG without altering its fatty acid profile.These findings establish a kinetic model of the three-step esterification and highlight the importance of acyl migration in enzymatic DAG synthesis.
文摘The optically active R-4-phenyl-2-hydroxy butyrates were prepared by esterification of the racemic acid or transesterification of the racemic ester catalyzed by lipase from Candida cyclindra (CCL) in organic media.
