scholarly journals Synthesis of Isopropyl Ferulate Using Silica-Immobilized Lipase in an Organic Medium

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Ashok Kumar ◽  
Shamsher Singh Kanwar
Keyword(s):  
Ferulic Acid ◽  
Molecular Sieves ◽  
Isopropyl Alcohol ◽  
Immobilized Lipase ◽  
Inhibitory Effect ◽  
Organic Medium ◽  
Molar Ratio ◽  
Forward Reaction ◽  
Salt Ions ◽  
The Matrix

Immobilization of lipases has proved to be a useful technique for improving an enzyme's activity in organic solvents. In the present study, the performance of a silica-immobilized lipase was evaluated for the synthesis of isopropyl ferulate in DMSO. The biocatalyst was cross-linked onto the matrix with 1% glutaraldehyde. The effects of various parameters, molar ratio of ferulic acid to isopropyl alcohol (25 mM : 100 mM), concentration of biocatalyst (2.5–20 mg/mL), molecular sieves (25–250 mg/mL), and various salt ions, were studied consecutively as a function of percent esterification. Immobilized lipase at 25 mg/mL showed maximum esterification (~84%) of ferulic acid and isopropanol at a molar ratio of 25 mM : 100 mM, respectively, in DMSO at 45°C in 3 h under shaking (150 rpm). To overcome the inhibitory effect of water (a byproduct) if any, in the reaction mixture, molecular sieves (3 Å × 1.5 mm; 100 mg/mL) were added to the reaction mixture to promote the forward reaction. Salt ions like Ca2+, Cd2+, and Fe2+ enhanced the activity of immobilized biocatalyst while a few ions like Co2+, Zn2+, Mg2+, Mn2+, Al3+, and Na+ had mild inhibitory effect. Approximately, one third of total decrease in the esterification efficacy was observed after the 5th repetitive cycle of esterification.

scholarly journals Enzymatic Synthesis of Isopropyl Acetate by Immobilized   Bacillus cereus Lipase in Organic Medium

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Madan Lal Verma ◽  
Wamik Azmi ◽  
Shamsher Singh Kanwar
Keyword(s):  
Acetic Acid ◽  
Bacillus Cereus ◽  
Water Activity ◽  
Molecular Sieves ◽  
Immobilized Lipase ◽  
Molar Ratio ◽  
Ester Synthesis ◽  
Initial Water ◽  
Isopropyl Acetate ◽  
Mg Addition

Selective production of fragrance fatty acid ester from isopropanol and acetic acid has been achieved using silica-immobilized lipase of Bacillus cereus MTCC 8372. A purified thermoalkalophilic extracellular lipase was immobilized by adsorption onto the silica. The effects of various parameters like molar ratio of substrates (isopropanol and acetic acid; 25 to 100 mM), concentration of biocatalyst (25–125 mg/mL), reaction time, reaction temperature, organic solvents, molecular sieves, and initial water activity were studied for optimal ester synthesis. Under optimized conditions, 66.0 mM of isopropyl acetate was produced when isopropanol and acetic acid were used at 100 mM: 75 mM in 9 h at 55°C in n-heptane under continuous shaking (160 rpm) using bound lipase (25 mg). Addition of molecular sieves (3 Å  × 1.5 mm) resulted in a marked increase in ester synthesis (73.0 mM). Ester synthesis was enhanced by water activity associated with pre-equilibrated saturated salt solution of LiCl. The immobilized lipase retained more than 50% of its activity after the 6th cycle of reuse.

scholarly journals Immobilization of lipase on sepabeads and its application in pentyl octanoate synthesis in a low aqueous system

2008 ◽  
pp. 139-152 ◽  
Author(s):  
Zorica Knezevic-Jugovic ◽  
SvetlanaV. Saponjic ◽  
Dejan Bezbradica ◽  
Dusan Mijin
Keyword(s):  
Molecular Sieves ◽  
Immobilized Lipase ◽  
Candida Rugosa ◽  
Aqueous System ◽  
Molar Ratio ◽  
Process Conditions ◽  
Initial Water Content ◽  
Initial Water ◽  
Initial Substrate ◽  
Substrate Molar Ratio

The object of the study was to investigate the process conditions relevant for the pentyl octanoate production with the lipase from Candida rugosa immobilized on Sepabeads EC-EP carrier. This is an epoxide-containing commercial polymethacrylic carrier with suitable characteristics for enzyme immobilization. The immobilized lipase suitable for pentyl octanoate synthesis has been prepared by a direct lipase binding to polymers via their epoxide groups. The enzymatic activity was determined by both hydrolysis of olive oil in an aqueous system and esterification of n-pentanol with octanoic acid in a low aqueous system. The influence of several important reaction parameters such as temperature, initial water content, initial substrate molar ratio, enzyme loading and time of adding of molecular sieves in the system is carefully analyzed by means of an experimental design. Production of the ester was optimized and an ester production response equation was obtained, making it possible to predict ester yields from known values of the five main factors. Almost complete conversion (>99%) of the substrate to ester could be realized, using lipase loading as low as 37 mg/g dry support and in a relatively short time (24 h) at 45?C, when high initial substrate molar ratio of 2.2 is used.

scholarly journals Optimization of lipase-catalyzed synthesis of polyethylene glycol stearate in a solvent-free system

2019 ◽  
Vol 8 (1) ◽  
pp. 30-37 ◽  
Author(s):  
Girish S. Nhivekar ◽  
Virendra K. Rathod
Keyword(s):  
Polyethylene Glycol ◽  
Molecular Sieves ◽  
Immobilized Lipase ◽  
Solvent Free ◽  
Molar Ratio ◽  
Resonance Spectroscopy ◽  
Free System ◽  
Immobilized Catalyst ◽  
Solvent Free System ◽  
The Impact

Abstract Polyethylene glycol stearate is widely used in pharmaceuticals and cosmetic industries. The current work describes the synthesis and optimization of polyethylene glycol stearate by esterification of polyethylene glycol 600 and stearic acid using Fermase CALBex 10000, a commercial immobilized lipase B in a solvent-free system. The impact of various parameters that include temperature, reaction time, biocatalyst loading, agitation, acid to alcohol molar ratio, and amount of molecular sieves was optimized to achieve maximum conversion. The highest conversion of 86.98% was obtained in 6 h under the following optimized conditions: temperature 70°C, biocatalyst loading 0.5%, acid to alcohol molar ratio 1:4, speed of agitation 300 rpm, and molecular sieves 5% (w/w). The final condensate product was analyzed through Fourier transform infrared spectroscopy to confirm the functional group and also by 1H nuclear magnetic resonance spectroscopy. The immobilized catalyst can be reused up to four cycles, exhibiting more than 60% of its initial activity.

The Effect of Acidity of Al and Fe Silicates with MFI Structure on Benzene and Toluene Alkylation with Isopropyl Alcohol

1996 ◽  
Vol 61 (8) ◽  
pp. 1115-1130 ◽  
Author(s):  
Jiří Čejka ◽  
Naděžda Žilková ◽  
Blanka Wichterlová
Keyword(s):  
Kinetic Study ◽  
Molecular Sieves ◽  
Isopropyl Alcohol ◽  
Acid Sites ◽  
Transport Rate ◽  
Reaction Products ◽  
Oh Groups ◽  
Benzene Alkylation ◽  
Toluene Alkylation ◽  
Low Strength

Kinetic study of toluene and benzene alkylation with isopropyl alcohol on alumo- and ferrisilicates of MFI structure has shown that the alkylation activity does not follow the acidity (both the number and strength of bridging OH groups) of these molecular sieves. The rate of the overall reaction is controlled by the desorption/transport rate of bulky, strongly adsorbed cymenes and cumene. A higher concentration of n-propyltoluenes compared to n-propylbenzene, both undesired reaction products, formed via a bimolecular isomerization of isopropyl aromate with benzene or toluene, was due to the higher reactivity of isopropyltoluene with toluene in comparison with that of cumene with benzene. It is concluded that ferrisilicates of MFI structure possessing low strength acid sites appear to be promising catalysts for achieving both a high isopropyl- and para-selectivity in toluene alkylation to p-cymene.

scholarly journals Thermal and Mechanical Behavior of Elastomers Incorporated with Thermoregulating Microcapsules

2021 ◽  
Vol 11 (12) ◽  
pp. 5370
Author(s):  
Ana M. Borreguero ◽  
Irene Izarra ◽  
Ignacio Garrido ◽  
Patrycja J. Trzebiatowska ◽  
Janusz Datta ◽  
...  
Keyword(s):  
Latent Heat ◽  
Continuous Improvement ◽  
Low Density Polyethylene ◽  
Molar Ratio ◽  
Low Density ◽  
Minimum Particle Size ◽  
Synergy Effects ◽  
Elastomeric Materials ◽  
The Matrix ◽  
Spherical Microparticles

Polyurethane (PU) is one of the principal polymers in the global plastic market thanks to its versatility and continuous improvement. In this work, PU elastomeric materials having thermoregulating properties through the incorporation of microcapsules (mSD-(LDPE·EVA-RT27)) from low-density polyethylene and vinyl acetate containing paraffin®RT27 as PCM were produced. Elastomers were synthesized while varying the molar ratio [NCO]/[OH] between 1.05 and 1.1 and the microcapsule (MC) content from 0.0 to 20.0 wt.%. The successful synthesis of the PUs was confirmed by IR analyses. All the synthesized elastomers presented a structure formed by a net of spherical microparticles and with a minimum particle size for those with 10 wt.% MC. The density and tensile strength decreased with the MC content, probably due to worse distribution into the matrix. Elastomer E-1.05 exhibited better structural and stability properties for MC contents up to 15 wt.%, whereas E-1.1, containing 20 wt.% MC, revealed mechanical and thermal synergy effects, demonstrating good structural stability and the largest latent heat. Hence, elastomers having a large latent heat (8.7 J/g) can be produced by using a molar ratio [NCO]/[OH] of 1.1 and containing 20 wt.% mSD-(LDPE·EVA-RT27).

scholarly journals Continuous Production of Lipase-Catalyzed Biodiesel in a Packed-Bed Reactor: Optimization and Enzyme Reuse Study

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Hsiao-Ching Chen ◽  
Hen-Yi Ju ◽  
Tsung-Ta Wu ◽  
Yung-Chuan Liu ◽  
Chih-Chen Lee ◽  
...  
Keyword(s):  
Flow Rate ◽  
Immobilized Lipase ◽  
Continuous Production ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Molar Ratio ◽  
System Response ◽  
Biodiesel Synthesis ◽  
Substrate Molar Ratio ◽  
Molar Conversion

An optimal continuous production of biodiesel by methanolysis of soybean oil in a packed-bed reactor was developed using immobilized lipase (Novozym 435) as a catalyst in atert-butanol solvent system. Response surface methodology (RSM) and Box-Behnken design were employed to evaluate the effects of reaction temperature, flow rate, and substrate molar ratio on the molar conversion of biodiesel. The results showed that flow rate and temperature have significant effects on the percentage of molar conversion. On the basis of ridge max analysis, the optimum conditions were as follows: flow rate 0.1 mL/min, temperature52.1∘C, and substrate molar ratio 1 : 4. The predicted and experimental values of molar conversion were83.31±2.07% and82.81±.98%, respectively. Furthermore, the continuous process over 30 days showed no appreciable decrease in the molar conversion. The paper demonstrates the applicability of using immobilized lipase and a packed-bed reactor for continuous biodiesel synthesis.

Lipase-Catalyzed Acyl-L-Carnitines Synthesis in [Bmim]PF6 Ionic Liquid

2009 ◽  
Vol 5 (1) ◽  
Author(s):  
Jin-qiang Tian ◽  
Qiang Wang ◽  
Zhong-yuan Zhang
Keyword(s):  
Ionic Liquid ◽  
Lipase Activity ◽  
Molecular Sieves ◽  
Reaction Medium ◽  
Molar Ratio ◽  
Reaction Conditions ◽  
Optimal Reaction ◽  
Better Than

In order to significantly improve the biosynthesis of acyl-L-carnitines catalyzed by lipase, there must be an efficient and suitable reaction medium that is not only polar but also hydrophobic. [Bmim]PF6, which satisfies the above two requirements, was applied as the medium. The optimal reaction conditions were: for isovaleryl-L-carnitine, 0.22aW, 200mg molecular sieves, 60ºC, 4:1 of molar ratio (fatty acid:L-carnitine), 150rpm and 60h; for octanoyl-L-carnitine and palmitoyl-L-carnitine, 0.22aW, 250 mg molecular sieves, 5:1 of molar ratio (fatty acid:L-carnitine), 200rpm, 48h, 60ºC (octanoyl-L-carnitine) and 65ºC (palmitoyl-L-carnitine). Their overall yields could reach 59.14%, 90.79% and 98.03%, respectively. The yields of isovaleryl-L-carnitine, octanoyl-L-carnitine and palmitoyl-L-carnitine in [Bmim]PF6 were 16.21%, 73.67% and 44.22 % more than those in acetonitrile, respectively. [Bmim]PF6 as the medium was better than acetonitrile. It could not only enhance the yields of acyl-L-carnitines, but also protect the lipase activity.

Natural maize phytochemicals for control of maize mycoflora and aflatoxigenic fungi

2009 ◽  
Vol 2 (3) ◽  
pp. 305-312 ◽  
Author(s):  
A. Nesci ◽  
S. Marín ◽  
M. Etcheverry ◽  
V. Sanchis
Keyword(s):  
Ferulic Acid ◽  
Incubation Period ◽  
Cinnamic Acid ◽  
Inhibitory Effect ◽  
Aspergillus Section Flavi ◽  
Aflatoxigenic Fungi ◽  
Incubation Periods ◽  
Maize Grain ◽  
Aflatoxin B ◽  
Aspergillus Section

This research was undertaken to evaluate the effects of the natural phytochemicals trans-cinnamic acid (CA) alone at concentrations of 20 and 25 mM, ferulic acid (FA) at concentration of 30 mM and two mixtures, CA-FA (20+30 mM) and CA-FA (25+30 mM) on natural maize mycoflora, Aspergillus section Flavi population and aflatoxin B1 production. These studies were carried out in maize grain in relation to a water activity of 0.99, 0.97 and 0.94. CA at 25 mM and the mixture CA-FA (25+30 mM) were the most effective treatments at inhibiting natural maize mycoflora at all aw assayed after 11 and 35 days of incubation at 25 °C. In general, 20 mM CA caused complete inhibition of Aspergillus section Flavi population at all aw values tested during all incubation period without an additional inoculum. 20 mM CA and 25 mM CA showed the major inhibitory effect on aflatoxin B1 accumulation of control and Aspergillus section Flavi additionally inoculated during all incubation periods. The data showed that CA and FA could be considered as effective fungitoxicants for natural maize mycoflora and aflatoxigenic fungi in the aw range 0.99 to 0.94. The information obtained shows promise for controlling aflatoxigenic fungi in stored maize.

scholarly journals Simplified Method to Optimize Enzymatic Esters Syntheses in Solvent-Free Systems: Validation Using Literature and Experimental Data

Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1357
Author(s):  
Ronaldo Rodrigues de Sousa ◽  
Ayla Sant’Ana da Silva ◽  
Roberto Fernandez-Lafuente ◽  
Viridiana Santana Ferreira-Leitão
Keyword(s):  
Immobilized Lipase ◽  
Solvent Free ◽  
Molar Ratio ◽  
Mathematical Tool ◽  
Enzymatic Esterification ◽  
Reaction Conditions ◽  
Reaction Behavior ◽  
Optimum Reaction ◽  
Interesting Correlation ◽  
Using Data

The adoption of biocatalysis in solvent-free systems is an alternative to establish a greener esters production. An interesting correlation between the acid:alcohol molar ratio and biocatalyst (immobilized lipase) loading in the optimization of ester syntheses in solvent-free systems had been observed and explored. A simple mathematical tool named Substrate-Enzyme Relation (SER) has been developed, indicating a range of reaction conditions that resulted in high conversions. Here, SER utility has been validated using data from the literature and experimental assays, totalizing 39 different examples of solvent-free enzymatic esterifications. We found a good correlation between the SER trends and reaction conditions that promoted high conversions on the syntheses of short, mid, or long-chain esters. Moreover, the predictions obtained with SER are coherent with thermodynamic and kinetics aspects of enzymatic esterification in solvent-free systems. SER is an easy-to-handle tool to predict the reaction behavior, allowing obtaining optimum reaction conditions with a reduced number of experiments, including the adoption of reduced biocatalysts loadings.

scholarly journals Involvement of the arachidonic acid cytochrome P450 epoxygenase pathway in the proliferation and invasion of human multiple myeloma cells

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1925 ◽  
Author(s):  
Jing Shao ◽  
Hongxiang Wang ◽  
Guolin Yuan ◽  
Zhichao Chen ◽  
Qiubai Li
Keyword(s):  
Multiple Myeloma ◽  
Arachidonic Acid ◽  
Cytochrome P450 ◽  
Biological Effects ◽  
Inhibitory Effect ◽  
Therapeutic Drug ◽  
Dependent Manner ◽  
The Matrix ◽  
Human Multiple Myeloma ◽  
Proliferation And Invasion

Cytochrome P450 (CYP) epoxygenases and the metabolites epoxyeicosatrienoic acids (EETs) exert multiple biological effects in various malignancies. We have previously found EETs to be secreted by multiple myeloma (MM) cells and to be involved in MM angiogenesis, but the role of the arachidonic acid cytochrome P450 epoxygenase pathway in the proliferation and mobility of MM cells remains unknown. In the present study, we found that MM cell lines generated detectable levels of 11,12-EET/14,15-EET and that increased levels of EETs were found in the serum of MM patients compared to healthy donors. The addition of exogenous EETs induced significantly enhanced proliferation of MM cells, whereas 17-octadecynoic acid (17-ODYA), an inhibitor of the CYP epoxygenase pathway, inhibited the viability and proliferation of MM cells. Moreover, this inhibitory effect could be successfully reversed by exogenous EETs. 17-ODYA also inhibited the motility of MM cells in a time-dependent manner, with a reduction of the gelatinolytic activity and protein expression of the matrix metalloproteinases (MMP)-2 and MMP-9. These results suggest the CYP epoxygenase pathway to be involved in the proliferation and invasion of MM cells, for which 17-ODYA could be a promising therapeutic drug.

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