Enzymatic Chemoselective Synthesis of Secondary-Amide Surfactant From N-Methylethanol Amine (original) (raw)
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Journal of Molecular Catalysis B: Enzymatic, 1998
Glucamide surfactants can be obtained by reacting amino-sugar derivatives with fatty acids in the presence of lipase enzymes in organic media. Reactions are catalyzed with Lipozyme in hexane or with Novozym in 2-methyl-2-butanol as solvents. In hexane, the formation of a salt complex between the fatty acid and N-methyl-glucamine allows the efficient acylation of the amine. Fatty acid conversion is limited to 50% due to salt formation. In 2-methyl-2-butanol, conversion yield of the fatty acid up to 100% can be obtained by removing the water coproduct under reduced pressure. Acido-basic conditions allow the control of the reaction chemoselectivity. This reaction can also be completed using various amines and acyl donors. q
Enzymatic synthesis of amide surfactants from ethanolamine
Enzyme and Microbial Technology, 2001
The condensation of a primary amine with fatty acids has been studied to determine optimum conditions for selective formation of amide surfactants via enzymatic amidification. Monoacylated ethanolamide and the diacylated amide-ester can be isolated from the reaction mixture, but the monoacylated ester cannot be isolated. The selectivity of the reaction depends on the solubility of the intermediate amide. Continuous precipitation of this product decreases the amount of amide-ester produced. Solubility values of the desired product (amide) are reported for different conditions. In acetonitrile, the ethyl ester of the corresponding fatty acid has been used successfully to avoid formation/precipitation of the ion-pair of the precursor reagents. In this medium, use of the transacylation reaction permits one to accelerate the reaction without producing a significant change in the selectivity toward the intermediate amide. This strategy is not successful in n-hexane where the solubilities of both ethanolamine and its ion-pair with lauric acid are similar. Results obtained for high loadings of substrates have been analyzed. In n-hexane and acetonitrile, the kinetics of the direct acylation reactions are controlled by the limited solubility of the ion pair formed by the two precursor reagents For the transacylation reaction in acetonitrile, at a sustrate loading of 2 mol l Ϫ1, selective production of as much as 92 mole percent N-acyl ethanolamine was observed in only 1.5 h.
Selective enzymatic synthesis of amide surfactants from diethanolamine
Enzyme and Microbial Technology, 2003
Kinetic strategies for selective preparation of amides from diethanolamine have been designed using Novozym 435 lipase as a biocatalyst. Two different routes, direct acylation and transacylation, have been optimized. In n-hexane, the reaction is more selective for formation of the amide by direct acylation, while in dioxane, the O-acylation reaction is highly favored. However, the initial rates of direct acylation and transacylation are both higher in dioxane than in n-hexane because of the low solubilities of both diethanolamine and its corresponding ion-pair complex with the fatty acid. At 30 • C, the high viscosities of mixtures of diethanolamine with fatty acids limit the extent of reaction and the corresponding yields of the amide. This effect is greater in n-hexane in which the viscosity (5.52 cSt) was four times greater than dioxane. An increase in temperature to 60 • C increases the conversion and decreases the viscosity of the n-hexane solution to 0.8-0.9 cSt. At 60 • C when equimolar amounts of reactants are employed, the transacylation route produces both higher conversions (71-77 mol%) and greater selectivities to the amide (74-94%) than the direct acylation reaction (69-74 mol% conversion and 76-86% selectivity). For both synthesis routes, the volumetric productivity of the reactor is restricted for reactant concentrations above 0.8 M. At 60 • C, conversions via the direct acylation reaction can be increased to 92 and 80 mol% in dioxane and n-hexane, respectively. These conversions require using a twofold excess of diethanolamine. The resultant selectivities are 98 and 100%, respectively.
The Optimization of Enzymatic Synthesis for Lauroyl-N-Methyl Glucamide Surfactants
Indonesian Journal of Chemistry
The optimization of enzymatic synthesis for lauroyl-N-methyl glucamide surfactants is studied. The fraction of palm kernel oil namely lauric acid (AL) was amidificationed with N-methyl glucamine (MGL) to produce lauroyl-Nmethyl glucamide. Study was carried out by using immobilized lipase from Candida antarctica (Novozyme 435 ® ), and tert-amylalcohol as a solvent. Response Surface Methodology (RSM) based on a five level, three variable design was employed, firstly, for studying the interactive effect of various parameters on the reaction, and secondly, for the optimization. The reaction parameters observed were Novozyme concentration, substrate molar ratio, and temperature. Simultaneously increasing Novozyme concentration, substrate molar ratio, and temperature improves the reaction yield and the effect of temperature is noted more significant. The expected optimum condition was at molar ratio MGL:AL 1:1, the Novozyme concentration of 8% and the reaction temperature of 50-55°C. The reactions at the optimum condition produce the convertion of lauric acid of 64.5% and yield of 96.5%. With the optimization procedure the higher alkyl glucamide yield was achieved.
Journal of colloid and interface science, 2014
Four new amide functionalized N-methylpiperazinium amphiphiles having tetradecyl, hexadecyl alkyl chain lengths and counterions; chloride or bromide have been synthesized and characterized by various spectroscopic techniques. These new surfactants have been investigated in detail for their self-assembling behavior by surface tension, conductivity and fluorescence measurements. The thermodynamic parameters of these surfactants indicate that micellization is exothermic and entropy-driven. The dynamic light scattering (DLS) and transmission electron microscopy (TEM) experiments have been performed to insight the aggregate size of these cationics. Thermal degradation of these new surfactants has also been evaluated by thermal gravimetric analysis (TGA). These new surfactants form stable complexes with DNA as acknowledged by agarose gel electrophoresis, ethidium bromide exclusion and zeta potential measurements. They have also been found to have low cytotoxicity by MTT (3-(4,5-dimethylth...
A biocatalysis based method for the solvent-free production of N-alkanoyl-N-methylglucamide (MEGA) surfactants was developed and used as a case study for the evaluation of different environmental assessment tools, such as the freeware package EATOS (Environmental Assessment Tool for Organic Synthesis). In order to also consider energy usage and process facilities, e.g. heating, stirring and vacuum, a complementary tool was needed; hence the EcoScale method and the use of an energy monitoring socket were also exploited. The solvent-free method followed by a simple hydrolysis step gave a final amide yield of 99% and a product essentially free of remaining substrate, N-methylglucamine (MEG). The latter is important since MEG can potentially be converted to carcinogenic nitrosamines. The absence of solvent in the reaction medium was also found to result in a significantly reduced potential environmental impact. The environmental tools used in this study were further scrutinized, and even if they represent some of the best freely available tools for evaluation of early stage process development, some points for further improvements are suggested.
Process Biochemistry, 2022
The enzymatic synthesis of sugar-based surfactants is often performed in non-conventional media that do not meet longer satisfy the current environmental acceptability, especially biodegradability and cytotoxicity. In this work, we propose an innovative sustainable route by replacing the current reference organic solvent, 2-methyl-2-butanol (2M2B), by 2methyltetrahydrofuran (MeTHF), an agrosolvent and 2-methyltetrahydrofuran-3-one (MeTHF-3-one), a food-grade ingredient used as solvent. These two neoteric solvents were thus evaluated as reaction media via lipase-catalyzed esterification of glucose by lauric acid and revealed a novel matter of interest. The regioselectivity of the reaction was mainly directed toward the primary alcohol of glucose maintaining the end-product obtained in 2M2B: D-glucose-6-O-laurate. The PLS-Surface Response Design evidenced enzymatic performances in ester production of 48% in MeTHF and 79% in MeTHF-3-one. The latter solvent resulted not only in better yields compared to 2M2B, but also in an increased enzymatic stability allowing better reuse of the catalyst. Demonstrated to be readily biodegradable according to OECD standards for the first time, MeTHF-3-one was substantiated as a green medium for efficient, selective and sustainable enzymatic synthesis of sugar esters.
Advanced Synthesis & Catalysis, 2008
A fully enzymatic methodology for the resolution of chiral amines has been demonstrated. Candida antarctica lipase B (CaLB)-catalyzed acylation with N-methyl-and N-phenylglycine, as well as analogues having the general formula R 1 À X À CH 2 CO 2 R 2 (R 1 = Me, Ph; X = O, S) afforded the corresponding enantioenriched amides, which were subsequently enzymatically hydrolyzed. Surprisingly, CaLB also proved to be the catalyst of choice for this latter step. The heteroatom in the acyl donor profoundly influences both the enzymatic acylation and deacylation; the O-substituted reagents performed best with regard to enantioselectivity as well as reaction rate in synthesis and hydrolysis.
Polymer, 2004
A novel chitosan-based polymeric surfactant, DG-chitosan, was prepared via reductive N-alkylation of chitosan with 3-O-dodecyl-Dglucose in acetate buffer (pH 4.3, 0.1 M)-methanol in the presence of sodium cyanoborohydride (NaBH 3 CN). DG-chitosan was swelling in water, partly dissolvable in pyridine and DMF, and completely soluble in 0.1% aqueous acetic acid. 1 H and 13 C NMR spectroscopic analyses in 2% acetic acid-d 4-methanol-d 4 together with elemental analysis showed the degree of substitution was 27%. Formation of polymeric micelles was observed by use of pyrene as a fluorescent probe, and the critical aggregation concentration (CAC) of DG-chitosan was marked equal to 28.1 mg/L.
Advanced Synthesis & Catalysis, 2008
A fully enzymatic methodology for the resolution of chiral amines has been demonstrated. Candida antarctica lipase B (CaLB)-catalyzed acylation with N-methyl-and N-phenylglycine, as well as analogues having the general formula R 1 À X À CH 2 CO 2 R 2 (R 1 = Me, Ph; X = O, S) afforded the corresponding enantioenriched amides, which were subsequently enzymatically hydrolyzed. Surprisingly, CaLB also proved to be the catalyst of choice for this latter step. The heteroatom in the acyl donor profoundly influences both the enzymatic acylation and deacylation; the O-substituted reagents performed best with regard to enantioselectivity as well as reaction rate in synthesis and hydrolysis.