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.
An isozyme of earthworm serine proteases acts on hydrolysis of triacylglycerol
Nakajima, Nobuyoshi,Sugimoto, Manabu,Tsuboi, Sadao,Tsuji, Hideaki,Ishihara, Kohji
, p. 2009 - 2011 (2005)
An enzyme catalyzing the hydrolysis of triacylglycerol was purified from an earthworm. The N-terminal amino acid sequence and the catalytic function of the purified enzyme were identical to those of Isozyme C, an isozyme of the earthworm-serine proteases. No other lipase proteins were found in the earthworm cells. The isozyme might act on the hydrolysis of triacylglycerol as well as the protein decomposition.
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.
Efficient synthesis of α-monoglycerides via solventless condensation of fatty acids with glycerol carbonate
Ghandi, Mehdi,Mostashari, Abdoljalil,Karegar, Mojgan,Barzegar, Mina
, p. 681 - 685 (2007)
Highly pure α-monoglycerides (5a-e) were successfully prepared in high yields by the condensation of fatty acids such as lauric, myristic, palmitic, stearic and oleic (2a-e) with glycerol carbonate (4-hydroxymethyl-1,3- dioxolan-2-one) (1) in the presence
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.
Non-ionic self-assembling amphiphilic polyester dendrimers as new drug delivery excipients
Sikwal, Dhiraj R.,Kalhapure, Rahul S.,Jadhav, Mahantesh,Rambharose, Sanjeev,Mocktar, Chunderika,Govender, Thirumala
, p. 14233 - 14246 (2017)
Solubility enhancement of poorly soluble antibiotics via self-assembling nano systems could be a promising approach to effectively treat bacterial infections in the current scenario of evolving resistant species. The study in this paper reports the synthesis of novel biocompatible G2 and G3 polyester amphiphilic dendrimers (ADs) (GMOA-G2-OH, GMOA-G3-OH, GMS-G2-OH and GMS-G3-OH) and their application as: (i) solubility enhancers for fusidic acid (FSD) as a model antibiotic with poor aqueous solubility and (ii) as stearic stabilizers in the preparation of solid lipid nanoparticles (SLNs). Two different series of ADs from glycerol monostearate (GMS) and glycerol monooleate (GMOA) were synthesized and their structures were confirmed employing FT-IR, NMR (1H and 13C) and HR-MS. The MTT assay confirmed their non-toxicity to mammalian cells. The critical aggregation concentration value order for ADs was GMS-G3-OH (5 × 10?6 mol l?1) ?6 mol l?1) ?5 mol l?1). All ADs formed micelles in the size range of 6.48 ± 0.04 nm to 12.38 ± 0.36 nm. At 1% w/w concentration FSD solubility enhancement in GMOA-G2-OH, GMOA-G3-OH, GMS-G2-OH and GMS-G3-OH was 43, 11, 9.1 and 6.8-fold respectively compared to water. As GMOA-G2-OH enabled the highest solubility of FSD, it was further evaluated for its antibacterial activity against Staphylococcus aureus and methicillin-resistant S. aureus (MRSA). The minimum inhibitory concentration values for FSD with and without GMOA-G2-OH against S. aureus were 0.23 μg ml?1 and 0.53 μg ml?1 respectively whereas the values were 0.23 μg ml?1 and 0.39 μg ml?1 against MRSA respectively. These results suggested that GM-OA-G2 not only enhanced the solubility but also enhanced antibacterial potency of FSD. Furthermore, these ADs showed their potential as promising pharmaceutical excipients as they acted as stearic stabilizers in the preparation of SLNs. Using these ADs stable SLNs with zeta potential value in the range of ?15.30 ± 1.44 to ?38.46 ± 3.04 were formed.
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.
Highly selective biocatalytic synthesis of monoacylglycerides in sponge-like ionic liquids
Lozano, Pedro,Gomez, Celia,Nieto, Susana,Sanchez-Gomez, Gregorio,García-Verdugo, Eduardo,Luis, Santiago V.
, p. 390 - 396 (2017)
The biocatalytic synthesis of monoacylglycerides (MAGs) was carried out by the direct esterification of fatty acids (i.e. capric, lauric, myristic, palmitic and oleic acids, respectively) with glycerol in different ionic liquids (ILs) based on cations with long alkyl side-chains (e.g. 1-hexadecyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [C16mim][NTf2], 1-dodecyl-3-methylimidazolium tetrafluoroborate [C12mim][BF4], etc.). Although all ILs have been shown as suitable reaction media for Novozym 435-catalyzed esterification of glycerol with free fatty acids, a high selectivity of MAGs was only observed in the [C12mim][BF4] case (e.g. up to 100% selectivity and 100% yield for monolaurin). Furthermore, as these ILs are temperature switchable ionic liquid/solid phases that behave as sponge-like systems, a straightforward protocol for IL-free MAG recovery, based on iterative centrifugations at controlled temperature, has been developed.
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.
