Parameters Influencing Lipase-Catalyzed Glycolipid Synthesis by (Trans-)Esterification Reaction

2021 ◽  
Author(s):  
Rebecca Hollenbach ◽  
Katrin Ochsenreither ◽  
Christoph Syldatk
Keyword(s):  
Esterification Reaction ◽  
Glycolipid Synthesis

scholarly journals Enzymatic Synthesis of Glucose Monodecanoate in a Hydrophobic Deep Eutectic Solvent

2020 ◽  
Vol 21 (12) ◽  
pp. 4342 ◽  
Author(s):  
Rebecca Hollenbach ◽  
Katrin Ochsenreither ◽  
Christoph Syldatk
Keyword(s):  
Deep Eutectic Solvent ◽  
Deep Eutectic Solvents ◽  
Decanoic Acid ◽  
Significant Loss ◽  
Esterification Reaction ◽  
Initial Reaction ◽  
Reaction Velocity ◽  
Glycolipid Synthesis ◽  
Reaction Media ◽  
First Time

Environmentally friendly and biodegradable reaction media are an important part of a sustainable glycolipid production in the transition to green chemistry. Deep eutectic solvents (DESs) are an ecofriendly alternative to organic solvents. So far, only hydrophilic DESs were considered for enzymatic glycolipid synthesis. In this study, a hydrophobic DES consisting of (-)-menthol and decanoic acid is presented for the first time as an alternative to hydrophilic DES. The yields in the newly introduced hydrophobic DES are significantly higher than in hydrophilic DESs. Different reaction parameters were investigated to optimize the synthesis further. Twenty milligrams per milliliter iCalB and 0.5 M glucose resulted in the highest initial reaction velocity for the esterification reaction, while the highest initial reaction velocity was achieved with 1.5 M glucose in the transesterification reaction. The enzyme was proven to be reusable for at least five cycles without significant loss of activity.

PEMBUATAN SURFAKTAN DARI ASAM OLEAT

2019 ◽  
Vol 1 (3) ◽  
pp. 68
Author(s):  
Puguh Setyopratomo ◽  
Edy Purwanto ◽  
H. Yefrico ◽  
H. Yefrico
Keyword(s):  
Oleic Acid ◽  
Optimum Condition ◽  
Reaction Temperature ◽  
Catalyst Concentration ◽  
Acid Number ◽  
Esterification Reaction ◽  
Number Density ◽  
Sample Analysis ◽  
Reaction Conversion ◽  
Glycerol Mono

The synthesis of glycerol mono oleic from oleic acid and glycerol is classified as an esterification reaction. This research is aimed to study the influent of reaction temperature and catalyst concentration on reaction conversion. During the experiment the temperature of reaction mixture was varied as 110 oC, 130 oC, and 150 oC, while the catalyst concentration of 1%, 3 %, and 5% was used. The batch experiment was conducted in a glass reactor equipped with termometer, agitator, and reflux condensor. The oleic acid – glycerol mol ratio of 1 : 2 was used as a mixture feed. To maintain the reaction temperature at certain level, the oil bath was used. After the temperature of reaction mixture was reached the expected value, then H2SO4 catalyst was added to the reactor.  To measure the extent of the reaction, every 30 minutes the sample was drawn out from the reactor vessel. The sample analysis include acid number, density, and viscosity measurement. From this research the optimum condition which is the temperature of reaction of 150 oC and 1% catalyst concentration was obtained. At this optimum condition the convertion reach 86% and the analysis of other physical properties of the product show the acid number of 24.12, the density of 0.922 g/cc, and the viscosity of 118.4 cp.

Engine Performance with Diesel-Biodiesel Blends Fuel and Emission Characteristics

2020 ◽  
Vol 38 (5A) ◽  
pp. 779-788
Author(s):  
Marwa N. Kareem ◽  
Adel M. Salih
Keyword(s):  
Sulfur Content ◽  
Diesel Fuel ◽  
Engine Performance ◽  
Esterification Reaction ◽  
Biodiesel Fuel ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Biodiesel Blends ◽  
Fuel Blends ◽  
Hc Emissions

In this study, the sunflowers oil was utilized as for producing biodiesel via a chemical operation, which is called trans-esterification reaction. Iraqi diesel fuel suffers from high sulfur content, which makes it one of the worst fuels in the world. This study is an attempt to improve the fuel specifications by reducing the sulfur content of the addition of biodiesel fuel to diesel where this fuel is free of sulfur and has a thermal energy that approaches to diesel.20%, 30% and 50% of Biodiesel fuel were added to the conventional diesel. Performance tests and pollutants of a four-stroke single-cylinder diesel engine were performed. The results indicated that the brake thermal efficiency a decreased by (4%, 16%, and 22%) for the B20, B30 and B50, respectively. The increase in specific fuel consumption was (60%, 33%, and 11%) for the B50, B30, and B20 fuels, respectively for the used fuel blends compared to neat diesel fuel. The engine exhaust gas emissions measures manifested a decreased of CO and HC were CO decreased by (13%), (39%) and (52%), and the HC emissions were lower by (6.3%), (32%), and (46%) for B20, B30 and B50 respectively, compared to diesel fuel. The reduction of exhaust gas temperature was (7%), (14%), and (32%) for B20, B30 and B50 respectively. The NOx emission increased with the increase in biodiesel blends ratio. For B50, the raise was (29.5%) in comparison with diesel fuel while for B30 and B20, the raise in the emissions of NOx was (18%) and...

Polymer-Bound Triphenylphosphine and 4,4′-Dinitroazobenzene as a Coupling Reagents for Chromatography-Free Esterification Reaction

2019 ◽  
Vol 16 (7) ◽  
pp. 1024-1031
Author(s):  
Diparjun Das ◽  
Kalyani Rajkumari ◽  
Lalthazuala Rokhum
Keyword(s):  
Microwave Irradiation ◽  
Solid Phase ◽  
Reaction System ◽  
Triphenylphosphine Oxide ◽  
High Yield ◽  
Sustainable Chemistry ◽  
Esterification Reaction ◽  
Coupling Reagent ◽  
Simple Filtration ◽  
Esterification Reactions

Aim and Objective: Sustainable production of fine chemicals both in industries and pharmaceuticals heavily depends on the application of solid-phase synthesis route coupled with microwave technologies due to their environmentally benign nature. In this report, a microwave-assisted esterification reaction using polymer-bound triphenylphosphine and 4,4′-dinitroazobenzene reagent system was investigated. Materials and Methods: The solvents were obtained from Merck India. Polymer-bound triphenylphosphine (~3 mmol triphenylphosphine moiety/g) was acquired from Sigma-Aldrich. The progress of the reaction was observed by thin-layer chromatography. All the reactions were performed in Milestones StartSYNTH microwave. The NMR spectra were recorded on Bruker Avance III 300, 400, and 500 MHz FT NMR Spectrometers. Using azo compound and polymer-bound triphenyl phosphine as a coupling reagent, esterification of different carboxylic acids with alcohols was performed under microwave irradiation. Results: Esterification of benzoic acid with 1-propanol under microwave irradiation gave a high yield of 92% propyl benzoate in 60 minutes only. Isolation of the ester products was relatively simple as both the byproducts polymer-bound triphenylphosphine oxide and hydrazine could be removed by simple filtration. The rates of reactions were found to be directly proportional to the pKa of the benzoic acids. Conclusion: 4,4′-Dinitroazobenzene was introduced as a novel coupling reagent, in conjugation with polymer-bound triphenylphosphine, for esterification reactions under microwave irradiation. The low moisture sensitivity of the reaction system, easy separation of the byproducts, and column chromatographyfree isolation of esters help our methods with application significance, particularly from the ‘Sustainable Chemistry’ perspective.

scholarly journals Incorporation of Poly(Itaconic Acid) with Quaternized Thiazole Groups on Gelatin-Based Films for Antimicrobial-Active Food Packaging

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 200
Author(s):  
Celeste Cottet ◽  
Andrés G. Salvay ◽  
Mercedes A. Peltzer ◽  
Marta Fernández-García
Keyword(s):  
Antimicrobial Activity ◽  
Itaconic Acid ◽  
Food Packaging ◽  
Crosslinking Agent ◽  
Radical Scavenging ◽  
Proton Nuclear Magnetic Resonance ◽  
Esterification Reaction ◽  
Alkylation Reaction ◽  
Vapor Permeability ◽  
Active Food Packaging

Poly(itaconic acid) (PIA) was synthesized via conventional radical polymerization. Then, functionalization of PIA was carried out by an esterification reaction with the heterocyclic groups of 1,3-thiazole and posterior quaternization by N-alkylation reaction with iodomethane. The modifications were confirmed by Fourier transform infrared (FTIR) and proton nuclear magnetic resonance (1H-NMR), as well as ζ-potential measurements. Their antimicrobial activity was tested against different Gram-negative and Gram-positive bacteria. After characterization, the resulting polymers were incorporated into gelatin with oxidized starch and glycerol as film adjuvants, and dopamine as crosslinking agent, to develop antimicrobial-active films. The addition of quaternized polymers not only improved the mechanical properties of gelatin formulations, but also decreased the solution absorption capacity during the swelling process. However, the incorporation of synthesized polymers increased the deformation at break values and the water vapor permeability of films. The antioxidant capacity of films was confirmed by radical scavenging ability and, additionally, those films exhibited antimicrobial activity. Therefore, these films can be considered as good candidates for active packaging, ensuring a constant concentration of the active compound on the surface of the food, increasing products’ shelf-life and reducing the environmental impact generated by plastics of petrochemical origin.

scholarly journals Thermal, Physical and Mechanical Properties of Poly(Butylene Succinate)/Kenaf Core Fibers Composites Reinforced with Esterified Lignin

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2359
Author(s):  
Harmaen Ahmad Saffian ◽  
Masayuki Yamaguchi ◽  
Hidayah Ariffin ◽  
Khalina Abdan ◽  
Nur Kartinee Kassim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Loss Modulus ◽  
Physical And Mechanical Properties ◽  
Weight Percent Gain ◽  
Weight Percent ◽  
Esterification Reaction ◽  
Butylene Succinate ◽  
Kenaf Core ◽  
Modified Lignin

In this study, Kraft lignin was esterified with phthalic anhydride and was served as reinforcing filler for poly(butylene succinate) (PBS). Composites with different ratios of PBS, lignin (L), modified lignin (ML) and kenaf core fibers (KCF) were fabricated using a compounding method. The fabricated PBS composites and its counterparts were tested for thermal, physical and mechanical properties. Weight percent gain of 4.5% after lignin modification and the FTIR spectra has confirmed the occurrence of an esterification reaction. Better thermo-mechanical properties were observed in the PBS composites reinforced with modified lignin and KCF, as higher storage modulus and loss modulus were recorded using dynamic mechanical analysis. The density of the composites fabricated ranged from 1.26 to 1.43 g/cm3. Water absorption of the composites with the addition of modified lignin is higher than that of composites with unmodified lignin. Pure PBS exhibited the highest tensile strength of 18.62 MPa. Incorporation of lignin and KCF into PBS resulted in different extents of reduction in tensile strength (15.78 to 18.60 MPa). However, PBS composite reinforced with modified lignin exhibited better tensile and flexural strength compared to its unmodified lignin counterpart. PBS composite reinforced with 30 wt% ML and 20 wt% KCF had the highest Izod impact, as fibers could diverge the cracking propagation of the matrix. The thermal conductivity value of the composites ranged from 0.0903 to 0.0983 W/mK, showing great potential as a heat insulator.

scholarly journals Phosphorus stress induces the synthesis of novel glycolipids in Pseudomonas aeruginosa that confer protection against a last-resort antibiotic

2021 ◽  
Author(s):  
Rebekah A. Jones ◽  
Holly Shropshire ◽  
Caimeng Zhao ◽  
Andrew Murphy ◽  
Ian Lidbury ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Antibiotic Sensitivity ◽  
Polymyxin B ◽  
Growth Conditions ◽  
Membrane Lipid ◽  
Comparative Genomic ◽  
P Limitation ◽  
Lung Microbiome ◽  
Glycolipid Synthesis

AbstractPseudomonas aeruginosa is a nosocomial pathogen with a prevalence in immunocompromised individuals and is particularly abundant in the lung microbiome of cystic fibrosis patients. A clinically important adaptation for bacterial pathogens during infection is their ability to survive and proliferate under phosphorus-limited growth conditions. Here, we demonstrate that P. aeruginosa adapts to P-limitation by substituting membrane glycerophospholipids with sugar-containing glycolipids through a lipid renovation pathway involving a phospholipase and two glycosyltransferases. Combining bacterial genetics and multi-omics (proteomics, lipidomics and metatranscriptomic analyses), we show that the surrogate glycolipids monoglucosyldiacylglycerol and glucuronic acid-diacylglycerol are synthesised through the action of a new phospholipase (PA3219) and two glycosyltransferases (PA3218 and PA0842). Comparative genomic analyses revealed that this pathway is strictly conserved in all P. aeruginosa strains isolated from a range of clinical and environmental settings and actively expressed in the metatranscriptome of cystic fibrosis patients. Importantly, this phospholipid-to-glycolipid transition comes with significant ecophysiological consequence in terms of antibiotic sensitivity. Mutants defective in glycolipid synthesis survive poorly when challenged with polymyxin B, a last-resort antibiotic for treating multi-drug resistant P. aeruginosa. Thus, we demonstrate an intriguing link between adaptation to environmental stress (nutrient availability) and antibiotic resistance, mediated through membrane lipid renovation that is an important new facet in our understanding of the ecophysiology of this bacterium in the lung microbiome of cystic fibrosis patients.

Study on the Synthesis of Isoamyl Acetate Catalyzed by Strong Acidic Cation Exchange Resin

2011 ◽  
Vol 396-398 ◽  
pp. 2411-2415 ◽  
Author(s):  
Ping Lan ◽  
Li Hong Lan ◽  
Tao Xie ◽  
An Ping Liao
Keyword(s):  
Acetic Acid ◽  
Reaction Time ◽  
Cation Exchanger ◽  
Cation Exchange Resin ◽  
Isoamyl Acetate ◽  
Molar Ratio ◽  
Esterification Reaction ◽  
Reaction Conditions ◽  
Optimum Reaction

Isoamyl acetate was synthesized from isoamylol and glacial acetic acid with strong acidic cation exchanger as catalyst. The effects of reaction conditions such as acid-alcohol ratio, reaction time, catalyst dosage to esterification reaction have been investigated and the optimum reaction conditions can be concluded as: the molar ratio of acetic acid to isoamylol 0.8:1, reaction time 2h, 25 % of catalyst (quality of acetic acid as benchmark). The conversion rate can reach up to 75.46%. The catalytic ability didn’t reduce significantly after reusing 10 times and the results showed that the catalyst exhibited preferably catalytic activity and reusability.

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