certified reference material, 5000 μg/mL in pyridine
111-03-5Relevant articles and documents
Improved enzymatic synthesis route for highly purified diacid 1,3-diacylglycerols
Wang, Xingguo,Wang, Xiaosan,Xiao, Jianhui,Zou, Wanzhen,Han, Zhengyang,Jin, Qingzhe
, p. 388 - 394 (2015)
The nutritional benefits and biological functions of diacylglycerols (DAGs) have attracted much attention regarding their synthesis. In this study, we improved the synthesis of diacid 1,3-DAGs by the enzymatic transesterification of 1-monoolein with a fatty acid vinyl ester as an acyl donor. First, 1-monoolein was prepared in 95% ethanol with Amberlyst resin as a catalyst by the cleavage of 1,2-acetonide-3-oleoylglycerol, which had been synthesized by enzymatic esterification of 1,2-acetonide glycerol with oleic acid. Second, purified 1-monoolein was reacted with vinyl palmitate in the presence of a lipase to obtain 1-oleoyl-3-palmitoylglycerol. Subsequently, the reaction conditions for the synthesis of diacid 1,3-DAGs were evaluated. Under the selected conditions, the crude mixture contained 90.6% pure 1-oleoyl-3-palmitoylglycerol. After purification by two-step crystallization, pure 1-oleoyl-3-palmitoylglycerol was obtained with a yield of 83.6%. The main innovations were the use of enzymatic transesterification to obtain highly purified diacid 1,3-DAGs instead of using chemical synthesis and the use of an irreversible reaction with a fatty acid vinyl ester as acyl donor rather than reversible reactions.
MgO-based catalysts for monoglyceride synthesis from methyl oleate and glycerol: Effect of Li promotion
Ferretti,Apesteguía,Di Cosimo
, p. 146 - 153 (2011)
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.
Study on acyl migration kinetics of partial glycerides: Dependence on temperature and water activity
Li, Wei,Du, Wei,Li, Qiang,Sun, Ting,Liu, Dehua
, p. 17 - 22 (2010)
Acyl migration phenomenon was often observed during 1,3-positional specificity lipase-catalyzed reactions from triglycerides and partial glycerides, including acyl migration of 1,2-diglyceride (1,2-DG) to 1,3-diglyceride (1,3-DG) and 2-monoglyceride (2-MG) to 1-monoglyceride (1-MG). However, the acyl migration mechanism and kinetics were seldom studied despite of numerous researches on process optimization of 1,3-positional specificity lipase-catalyzed reaction. In this paper, the influence of related factors on acyl migration process as well as their influencing mechanism was further studied. It was found that temperature and water activity were two crucial factors that would influence acyl migration kinetics. Determination of the kinetic parameters under different temperatures revealed that the acyl migration reaction rates were greatly promoted by the increasing of temperature. The acyl migration rates of 1,2-diglyceride and 2-monoglyceride were quite different from each other, which was found to be due to the different activation energies. Further study of how would water influence the acyl migration process showed that water activity rather than water content was a key factor that influenced acyl migration and the acyl migration rate would decrease with the increase of water activity. It was further revealed that water activity influenced the charge dispersion of the transition state, which ultimately influenced the reaction activation energy and then influenced the acyl migration rate.
Enzyme, medium, and reaction engineering to design a low-cost, selective production method for mono- and dioleoylglycerols
Arcos,Otero
, p. 673 - 682 (1996)
The selective enzymic production of mono- and diolein (MO, DO) was optimized at high yields. A comparative study of the following distinct enzymic reactions was conducted: ethyl oleate glycerolysis, triolein (TO) glycerolysis, and direct esterification. Solvent-free systems were compared with media that contained different solvents. Native, modified (with polyethylene glycol), and immobilized lipases were used. Mechanical resistance, the support effect on enzyme and glycerol dispersion and on process reproducibility, and hydrophilicity of the support were considered in the process optimization. We report the use of an immobilized lipase on an inorganic support (Celite), which has high activities in both solid-phase glycerolysis (99% reaction conversion) and esterification (100% conversion). The optimum conditions for the distinct reactions were compared by considering their selectivities, conversions, yields, and cost of the substrates. We found less costly and more selective processes in the absence of solvents for glycerolysis of triolein and direct esterification. Although glycerolysis was the most interesting process to produce diolein, esterification was better for monoolein preparation with this biocatalyst. The esterification reaction yielded 93 wt% of MO, in the absence of either TO or oleic acid (OA), at low cost because of the 100% reaction conversion. Similar costs of the substrates (10.6 and 10.1 $/g) were necessary to obtain 67 and 80 wt% of DO in esterification and glycerolysis, respectively. The glycerolysis conversion was 96%. In esterification, the product mixture was impure, with a high amount of residual OA due to the low conversion (59%). The high activity of PSL-Celite in these solid-phase reactions has an advantage over the reactions with nonimmobilized lipases due to the ease of enzyme recovery. The absence of organic solvents reduces the need for solvent removal from the reaction mixtures.
Synthesis of monoglycerides by esterification of oleic acid with glycerol in heterogeneous catalytic process using tin-organic framework catalyst
Wee, Lik H.,Lescouet, Tristan,Fritsch, Julia,Bonino, Francesca,Rose, Marcus,Sui, Zhijun,Garrier, Eva,Packet, Dirk,Bordiga, Silvia,Kaskel, Stefan,Herskowitz, Moti,Farrusseng, David,Martens, Johan A.
, p. 356 - 363 (2013)
Selective synthesis of monoglycerides by esterification of glycerol with fatty acids is a difficult reaction because of immiscibility of reagents and the formation of di- and tri-glyceride by-products. In this work a heterogeneous catalytic process was conceived in which the reactant mixture was homogenized using tert-butanol solvent. Candidate catalysts were screened in the reaction of oleic acid with glycerol. While under such reaction conditions zeolites were rather inactive, metal-organic frameworks and, especially, tin-organic frameworks were found promising. A tin-organic framework (Sn-EOF) was most active and achieved ≥98 % monoglyceride selectivity at 40 % conversion in catalyzing esterification of oleic acid with glycerol at a low reaction temperature of 150 C. Leaching of tin from Sn-EOF catalyst was suppressed by limiting the amount of oleic acid in the starting mixture. Characterization of the acid sites of Sn-EOF by pyridine-chemisorption and FTIR revealed Lewis acidity to be responsible for the catalytic activity.
High-selectivity synthesis method of long-chain fatty acid monoglyceride
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Paragraph 0047; 0050, (2019/02/27)
The invention belongs to the field of fatty acid and synthetic fatty acid glycerides and relates to a high-selectivity synthesis method of long-chain fatty acid monoglyceride, in particular to a high-selectivity synthesis method of long-chain fatty acid and synthetic fatty acid glycerides. The method comprises the steps that tetraethyl silicate and glycerin are subjected to alcoholysis reaction, and part of glycerin is esterified to generate glyceryl silicate; then the glyceryl silicate is subjected to esterification reaction with fatty acid to generate fatty acid glyceride; finally the high activity (instability) of silicate ester is utilized to achieve hydrolysis under mild conditions to synthesize the synthetic fatty acid glyceride at high selectivity. A by-product is safe and harmlessSiO2. Accordingly, the product with high monoglyceride content is obtained by using a simple process under mild conditions.
Method for synthesizing high content of fatty acid monoglyceride production of nano TiO2 The method of (by machine translation)
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Paragraph 0049; 0052; 0053, (2019/03/28)
The invention belongs to the fatty acid glyceride synthesis and nano powder preparation field. In particular to fatty acid and glycerin synthesis of fatty acid monoglyceride, and cogeneration nano TiO2 Method. Method of this invention is: for the reaction of titanium tetrachloride and glycerin, glycerol partial esterification, generating titanate glycerides. Then with the fatty acid esterification reaction, to generate fatty acid glyceride titanate. Finally the use of a titanate high activity (instability), hydrolysis under mild conditions, synthesizing high-content fatty acid monoglyceride, the pressure of the by-product TiO2 Powder. Thus a simple process, under mild conditions, a high content of fatty acid monoglyceride product, production of nano TiO2 Powder. (by machine translation)
