24529-88-2Relevant articles and documents
Stereospecific synthesis of phosphatidylglycerol using a cyanoethyl phosphoramidite precursor
Storch, Judith,Struzik, Zachary J.,Thompson, David H.,Weerts, Ashley N.
, (2020/07/03)
Phosphatidylglycerols (PG) are a family of naturally occurring phospholipids that are responsible for critical operations within cells. PG are characterized by an (R) configuration in the diacyl glycerol backbone and an (S) configuration in the phosphoglycerol head group. Herein, we report a synthetic route to provide control over the PG stereocenters as well as control of the acyl chain identity.
Glycerolysis of methyl oleate on MgO: Experimental and theoretical study of the reaction selectivity
Belelli,Ferretti,Apesteguía,Ferullo,Di Cosimo
, p. 132 - 144 (2015/09/28)
The liquid-phase MgO-promoted glycerolysis of methyl oleate, a fatty acid methyl ester (FAME), to give acylglycerol products was studied both, experimentally and by density functional theory (DFT). Catalytic results showed that strongly basic low coordination O2- surface sites participate in kinetically relevant steps of the glycerolysis reaction. Changes in the selectivity toward the different mono- and diglyceride isomers were investigated by varying the reaction conditions. The main product was always α-glyceryl monooleate (α-MG), a monoglyceride with the ester fragment at one of the terminal positions of the glycerol molecule; the β-MG isomer, with the ester substituted at position 2 was obtained in much lower amounts. The molecular modeling of glycerol (Gly) and FAME adsorptions as well as of the glycerolysis reaction was carried out using periodic DFT calculations and a model of stepped MgO surface. Results indicated that FAME was more weakly adsorbed than Gly; the latter adsorbs on a coordinatively unsaturated surface O2- site with O-H bond breaking at position 2 of the Gly molecule, giving therefore a surface β-glyceroxide species. Calculations explained the apparent contradiction between the preferential formation of the α-MG isomer and the energetically favored dissociation of the secondary OH group of Gly that leads to the β-glyceroxide species. They predict that the β-glyceroxide species participates in the pathways conducting to both, α- and β-MG isomers. Synthesis of α-MG occurs by C-O coupling of β-glyceroxide with FAME at one of the two primary OH groups of the β-glyceroxide species. Two transition states (TS) and a tetrahedral intermediate (TI) are involved in both, α-MG and β-MG isomer formation. However, the pathway toward β-MG is limited by the large sterical effects associated to the TI formation. Contrarily, the TI leading to α-MG is relatively easy to form.
An insight into the solvent effect on the positional selectivity of the immobilized lipase from Burkholderia cepacia in 1,3-diolein synthesis
Bi, Yan-Hong,Wang, Zhao-Yu,Duan, Zhang-Qun,Zhao, Xiang-Jie,Chen, Xiao-Ming,Nie, Ling-Hong
, p. 23122 - 23124 (2015/06/02)
The solvent effect on the positional selectivity of the immobilized lipase from Burkholderia cepacia in 1,3-diolein synthesis was investigated for the first time. The results indicated that the preferential selectivity to sn-1 hydroxyl of the glycerol molecule over sn-2 hydroxyl was weaker in solvents with higher logP values.
Highly efficient solvent-free synthesis of 1,3-diacylglycerols by lipase immobilised on nano-sized magnetite particles
Meng, Xiao,Xu, Gang,Zhou, Qin-Li,Wu, Jian-Ping,Yang, Li-Rong
, p. 319 - 324 (2013/10/08)
Recently, 1,3-DAGs (1,3-diacylglycerols) have attracted considerable attention as healthy components of food, oil and pharmaceutical intermediates. Generally, 1,3-DAG is prepared by lipase-mediated catalysis in a solvent free system. However, the system's high reaction temperature (required to reach the reactants' melting point), high substrate concentration and high viscosity severely reduce the lipase's activity, selectivity and recycling efficiency. In this report, MjL (Mucor javanicus lipase) was found to have the best performance in the solvent-free synthesis of 1,3-DAGs of several common commercial lipases. By covalent binding to amino-group-activated NSM (nano-sized magnetite) particles and cross-linking to form an enzyme aggregate coat, MjL's specific activity increased 10-fold, and was able to be reused for 10 cycles with 90% residual activity at 55 °C. 1,3-DAGs of lauric, myristic, palmitic, stearic, oleic and linoleic acid were prepared using the resulting immobilised enzyme, all with yields greater than 90%, and the reaction time was also greatly reduced.
1-O-Alkyl (di)glycerol ethers synthesis from methyl esters and triglycerides by two pathways: Catalytic reductive alkylation and transesterification/reduction
Sutter, Marc,Dayoub, Wissam,Metay, Estelle,Raoul, Yann,Lemaire, Marc
supporting information, p. 786 - 797 (2013/04/24)
From available and bio-sourced methyl esters, monoglycerides or oleic sunflower refined oil, the corresponding 1-O-alkyl (di)glycerol ethers were obtained in both high yields and selectivity by two different pathways. With methyl esters, a reductive alkylation with (di)glycerol was realized under 50 bar hydrogen pressure in the presence of 1 mol% of Pd/C and an acid co-catalyst. A second two step procedure was evaluated from methyl esters or triolein and consisted of a first transesterification to the corresponding monoglyceride with a BaO/Al2O3 catalyst, then its reduction to the desired glycerol monoether with a recyclable heterogeneous catalytic system Pd/C and Amberlyst 35 under H2 pressure. In addition, a mechanism for the reaction was also proposed.
Zirconium phenyl phosphonate phosphite as a highly active, reusable, solid acid catalyst for producing fatty acid polyol esters
Varhadi, Poonam,Kotwal, Mehejabeen,Srinivas
, p. 129 - 136 (2013/07/26)
The application of zirconium phenyl phosphonate phosphite (ZrPP) as a solid acid catalyst for producing polyol esters by esterification of glycerol or trimethylolpropane with a fatty acid (C8-C18.1) is reported for the first time. ZrPP exhibits high catalytic activity and in particular, (di + tri) esters selectivity (92.3 mol%). These esters of polyols are known for their application as biolubricants. The catalyst prepared using phosphorous acid to phenyl phosphonic acid molar ratio of 3:1 was found superior. The influence of process parameters on activity and selectivity of the catalyst was investigated. ZrPP was reusable in at least three recycling experiments. Hydrophobicity due to exposed phenyl groups on the surface is the possible cause for superior esterification activity of this novel, solid catalyst.
Evaluation of Rhizopus oryzae lipase for the determination of regiodistribution in triacylglycerols with medium chain fatty acids
Perignon, Marlene,Lecomte, Jerome,Pina, Michel,Renault, Anne,Simonneau-Deve, Camille,Villeneuve, Pierre
experimental part, p. 89 - 96 (2012/04/04)
The nutritional profile and rheological behaviors of lipids is both due to fatty acid composition and regiodistribution on external and internal positions of triacylglycerol. Actual methods for regiodistribution analysis having some restrictions, there is still a need for investigating a safe, simple and environmentally friendly method for the sn-2 position analysis that could especially be used for the analysis of fats containing medium and short chain fatty acids. The objective of this study was to evaluate the 1,3-selectivity and typoselectivity of Rhizopus oryzae lipase in the presence of short/medium chain fatty acids in partial hydrolysis conditions used for regiodistribution analysis. Structured triacylglycerols containing eight-carbon-chain length fatty acids in the sn -2 position were chemically synthesized using DCC/DMAP coupling agent and purification steps by flash-chromatography. The final product showed very high purity and was used as the substrate for 1,3-selectivity evaluation. Typoselectivity was assessed by investigating partial hydrolysis of equimolar blends of homogeneous TAG. This study confirmed the 1,3-selectivity of Rhizopus oryzae lipase in the hydrolysis conditions used, and revealed that this lipase was less influenced by fatty acids chain length than pancreatic lipase. Considering this, Rhizopus oryzae lipase appeared to be a good candidate for regiodistribution analysis of fats containing medium and short chain fatty acids.
Optimization of Candida sp. 99-125 lipase catalyzed esterification for synthesis of monoglyceride and diglyceride in solvent-free system
Zhao, Yanjun,Liu, Junfeng,Deng, Li,Wang, Fang,Tan, Tianwei
body text, p. 157 - 162 (2012/07/01)
Esterification of glycerol and oleic acid catalyzed by lipase Candida sp. 99-125 was carried out to synthesize monoglyceride (MAG) and diglyceride (DAG) in solvent-free system. Beta-cyclodextrin as an assistant was mixed with the lipase powder. Six reaction variables, initial water content (0-14 wt% of the substrate mass), the glycerol/oleic acid molar ratio (1:1-6:1), catalyst load (3-15 wt% of the substrate mass), reaction temperature (30-60 °C), agitator speed (130-250 r/min) and beta-cyclodextrin/lipase mass ratio (0-2) were optimized. The optimal conditions to the synthesis of MAG and DAG were different: the optimal glycerol/oleic acid molar ratio, beta-cyclodextrin/lipase mass ratio, catalyst load and reaction temperature were 6:1, 0, 5%, 50 °C for MAG, and 5:1, 1.5, 10%, 40 °C for DAG, respectively. The optimal water content and agitator speed for both MAG and DAG were 10% and 190 r/min, respectively. Under the optimal conditions, 49.6% MAG and 54.3% DAG were obtained after 8 h and 4 h, respectively, and the maximum of 81.4% MAG plus DAG (28.1% MAG and 53.3% DAG) was obtained after 2 h under the DAG optimal condition. Above 90% purity of MAG and DAG can be obtained by silica column separation.
MgO-based catalysts for monoglyceride synthesis from methyl oleate and glycerol: Effect of Li promotion
Ferretti,Apesteguía,Di Cosimo
experimental part, p. 146 - 153 (2012/02/01)
The synthesis of monoglycerides (glyceryl monooleates) by heterogeneously catalyzed glycerolysis of an unsaturated fatty acid methyl ester (methyl oleate) was studied on MgO and Li-promoted MgO catalysts. Several MgO-based catalysts with different Li loadings were prepared by incipient wetness impregnation and characterized by XRD, N2 physisorption, and FTIR and TPD of CO 2 among other techniques. Promotion of MgO with lithium, a basic promoter, affected the textural and structural properties of the resulting oxides so that more crystalline MgO phases with decreased surface area were obtained at increasing Li contents. Furthermore, the addition of Li generated new strong base sites because of formation of dispersed surface Li2O species, and thereby increased the total base site density of parent MgO. Li-containing MgO catalysts efficiently promoted the glycerolysis reaction, achieving high monoglyceride yields (70-73%) at 493 K. The initial monoglyceride formation rate increased linearly with the Li content on the sample following the enhanced overall catalyst base strength. Although conversions at the end of the run were ≈100% for all the catalysts, the monoglyceride selectivity slightly decreased with the Li loading, probably as a consequence of the less surface affinity for glycerol adsorption that facilitates competing monoglyceride re-adsorption and transformation to diglycerides by consecutive glycerolysis or disproportionation reactions.
Synthesis and properties of ascorbyl esters catalyzed by lipozyme TL im using triglycerides as acyl donors
Reyes-Duarte,Lopez-Cortes,Torres,Comelles,Parra,Pena,Ugidos,Ballesteros,Plou
scheme or table, p. 57 - 64 (2011/10/04)
Esters of l-ascorbic acid with long-chain fatty acids (E-304) are employed as antioxidants in foods rich in lipids. Although their enzymatic synthesis offers some advantages compared with the current chemical processes, most of the reported methods employ the immobilized lipase from Candida antarctica as biocatalyst and free fatty acids or activated esters as acyl donors. In order to diminish the cost of the process, we have investigated the synthesis of ascorbyl oleate and ascorbyl palmitate esters with the immobilized Thermomyces lanuginosus lipase Lipozyme TL IM-which is significantly less expensive than Novozym 435-and triglycerides as source of fatty acids. Lipozyme TL IM gave rise to a lower yield of 6-O-ascorbyl oleate than Novozym 435 when using triolein (64 vs. 84%) and olive oil (27 vs. 33%) as acyl donors. Both 6-O-ascorbyl oleate and 6-O-ascorbyl palmitate displayed excellent surfactant and antioxidant properties. The Trolox Equivalent Antioxidant Capability values for the oleate and palmitate were 71 and 84%, respectively, of those obtained with l-ascorbic acid; however, both derivatives were able to stabilize soybean oil towards peroxide formation.
