scholarly journals Immobilized Fe3O4-Polydopamine-Thermomyces lanuginosus Lipase-Catalyzed Acylation of Flavonoid Glycosides and Their Analogs: An Improved Insight Into Enzymic Substrate Recognition

2021 ◽  
Vol 9 ◽  
Author(s):  
Zhaoyu Wang ◽  
Yang Li ◽  
Mingyi Li ◽  
Xiaohui Zhang ◽  
Qingxia Ji ◽  
...  
Keyword(s):  
Reaction Rates ◽  
Thermomyces Lanuginosus ◽  
Flavonoid Glycosides ◽  
Hydroxyl Groups ◽  
Oh Groups ◽  
Thermomyces Lanuginosus Lipase ◽  
Phenolic Hydroxyl Groups ◽  
Insight Into ◽  
Long Chain ◽  
Steric Hindrances

The conversion of flavonoid glycosides and their analogs to their lipophilic ester derivatives was developed by nanobiocatalysts from immobilizing Thermomyces lanuginosus lipase (TLL) on polydopamine-functionalized magnetic Fe3O4 nanoparticles (Fe3O4-PDA-TLL). The behavior investigation revealed that Fe3O4-PDA-TLL exhibits a preference for long chain length fatty acids (i.e., C10 to C14) with higher reaction rates of 12.6–13.9 mM/h. Regarding the substrate specificity, Fe3O4-PDA-TLL showed good substrate spectrum and favorably functionalized the primary OH groups, suggesting that the steric hindrances impeded the secondary or phenolic hydroxyl groups of substrates into the bonding site of the active region of TLL to afford the product.

scholarly journals Composition and Structure of Ethanol-Lignins of Coniferous and Deciduous Wood and Products of their Catalytic Telomerization with 1,3-Butadiene

2021 ◽  
Vol 14 (4) ◽  
pp. 539-551
Author(s):  
Maxim A. Lutoshkin ◽  
◽  
Franck Rataboul ◽  
Laurent Djakovitch ◽  
Yuriy N. Malyar ◽  
...  
Keyword(s):  
Average Molecular Weight ◽  
Total Content ◽  
Gel Permeation Chromatography ◽  
Analysis Data ◽  
Elemental Analysis Data ◽  
Hydroxyl Groups ◽  
Oh Groups ◽  
Composition And Structure ◽  
Phenolic Hydroxyl Groups ◽  
Telomerization Reaction

The composition and structure of ethanol-lignins of coniferous (abies, pine) and deciduous (aspen, birch) wood and products of their catalytic telomerization with 1,3-butadiene has been studied with use of the methods 31P-NMR, gel-permeation chromatography, scanning electron microscopy and elemental analysis. Data on the nature and content of hydroxyl groups in ethanol-lignins were obtained using phosphorylation of lignins with 2-chloro‑4,4,5,5,-tetramethyl‑1,3,2-dioxaphospholane.The studied lignins differ from each other in the content of aliphatic, phenolic and carboxyl groups. The total content of hydroxyl groups increases in the series of ethanol-lignins: birch < aspen < pine < abies. For the modification of ethanol-lignins, the reaction of catalytic telomerization with 1,3-butadiene was used at 70 °C and 90 °C in the presence of a complex of palladium (II) diacetate with the sodium salt of triphenylphosphine trisulfate. By comparing the number of aliphatic, phenolic and carboxyl OH- groups in the initial and telomerized ethanol-lignins, it was found that only aliphatic and phenolic hydroxyl groups participate in the telomerization reaction. Telomerization of ethanol-lignins with 1,3-butadiene increases their average molecular weight and reduces polydispersity. The morphology of telomerized and initial samples of ethanol-lignins varies significantly

scholarly journals Reactivity of Aliphatic and Phenolic Hydroxyl Groups in Kraft Lignin towards 4,4′ MDI

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2131
Author(s):  
Leonardo Dalseno Antonino ◽  
Júlia Rocha Gouveia ◽  
Rogério Ramos de Sousa Júnior ◽  
Guilherme Elias Saltarelli Garcia ◽  
Luara Carneiro Gobbo ◽  
...  
Keyword(s):  
Experimental Work ◽  
Chemical Structure ◽  
31P Nmr ◽  
Kraft Lignin ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Diphenylmethane Diisocyanate ◽  
Complex Chemical ◽  
Heterogeneous Reactivity ◽  
Phenolic Hydroxyl Groups

Several efforts have been dedicated to the development of lignin-based polyurethanes (PU) in recent years. The low and heterogeneous reactivity of lignin hydroxyl groups towards diisocyanates, arising from their highly complex chemical structure, limits the application of this biopolymer in PU synthesis. Besides the well-known differences in the reactivity of aliphatic and aromatic hydroxyl groups, experimental work in which the reactivity of both types of hydroxyl, especially the aromatic ones present in syringyl (S-unit), guaiacyl (G-unit), and p-hydroxyphenyl (H-unit) building units are considered and compared, is still lacking in the literature. In this work, the hydroxyl reactivity of two kraft lignin grades towards 4,4′-diphenylmethane diisocyanate (MDI) was investigated. 31P NMR allowed the monitoring of the reactivity of each hydroxyl group in the lignin structure. FTIR spectra revealed the evolution of peaks related to hydroxyl consumption and urethane formation. These results might support new PU developments, including the use of unmodified lignin and the synthesis of MDI-functionalized biopolymers or prepolymers.

scholarly journals Development of Highly Efficient, Glassy Carbon Foam Supported, Palladium Catalysts for Hydrogenation of Nitrobenzene

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1172
Author(s):  
Ádám Prekob ◽  
Mahitha Udayakumar ◽  
Gábor Karacs ◽  
Ferenc Kristály ◽  
Gábor Muránszky ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Glassy Carbon ◽  
Palladium Nanoparticles ◽  
Palladium Catalysts ◽  
Sucrose Solution ◽  
Supported Catalyst ◽  
Carbon Foam ◽  
Hydroxyl Groups ◽  
Polyurethane Elastomers ◽  
Oh Groups

Glassy carbon foam (GCF) catalyst supports were synthesized from waste polyurethane elastomers by impregnating them in sucrose solution followed by pyrolysis and activation (AC) using N2 and CO2 gas. The palladium nanoparticles were formed from Pd(NO3)2. The formed palladium nanoparticles are highly dispersive because the mean diameters are 8.0 ± 4.3 (Pd/GCF), 7.6 ± 4.2 (Pd/GCF-AC1) and 4.4 ± 1.6 nm (Pd/GCF-AC2). Oxidative post-treatment by CO2 of the supports resulted in the formation of hydroxyl groups on the GCF surfaces, leading to a decrease in zeta potential. The decreased zeta potential increased the wettability of the GCF supports. This, and the interactions between –OH groups and Pd ions, decreased the particle size of palladium. The catalysts were tested in the hydrogenation of nitrobenzene. The non-treated, glassy-carbon-supported catalyst (Pd/GCF) resulted in a 99.2% aniline yield at 293 K and 50 bar hydrogen pressure, but the reaction was slightly slower than other catalysts. The catalysts on the post-treated (activated) supports showed higher catalytic activity and the rate of hydrogenation was higher. The maximum attained aniline selectivities were 99.0% (Pd/GCF-AC1) at 293 K and 98.0% (Pd/GCF-AC2) at 323 K.

scholarly journals Design of a New Gemini Lipoaminoacid with Immobilized Lipases Based on an Eco-Friendly Biosynthetic Process

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 164
Author(s):  
Patrícia M. Carvalho ◽  
Rita C. Guedes ◽  
Maria R. Bronze ◽  
Célia M. C. Faustino ◽  
Maria H. L. Ribeiro
Keyword(s):  
High Performance ◽  
Transfection Efficiency ◽  
Sol Gel ◽  
Reaction Rates ◽  
Solvent Free ◽  
Bioactive Molecules ◽  
Thermomyces Lanuginosus ◽  
Chemical Production ◽  
Immobilized Lipases ◽  
Free Media

Lipoaminoacids (LAA) are an important group of biosurfactants, formed by a polar hydrophilic part (amino acid) and a hydrophobic tail (lipid). The gemini LAA structures allow the formation of a supramolecular complex with bioactive molecules, like DNA, which provides them with good transfection efficiency. Since lipases are naturally involved in lipid and protein metabolism, they are an alternative to the chemical production of LAA, offering an eco-friendly biosynthetic process option. This work aimed to design the production of novel cystine derived gemini through a bioconversion system using immobilized lipases. Three lipases were used: porcine pancreatic lipase (PPL); lipase from Thermomyces lanuginosus (TLL); and lipase from Rizhomucor miehei (RML). PPL was immobilized in sol-gel lenses. L-cystine dihydrochloride and dodecylamine were used as substrates for the bioreaction. The production of LAA was evaluated by thin layer chromatography (TLC), and colorimetric reaction with eosin. The identification and quantification was carried out by High Performance Liquid Chromatographer-Mass Spectrometry (HPLC-MS/MS). The optimization of media design included co-solvent (methanol, dimethylsulfoxide), biphasic (n-hexane and 2-propanol) or solvent-free media, in order to improve the biocatalytic reaction rates and yields. Moreover, a new medium was tested where dodecylamine was melted and added to the cystine and to the biocatalyst, building a system of mainly undissolved substrates, leading to 5 mg/mL of LAA. Most of the volume turned into foam, which indicated the production of the biosurfactant. For the first time, the gemini derived cystine lipoaminoacid was produced, identified, and quantified in both co-solvent and solvent-free media, with the lipases PPL, RML, and TLL.

Promoting protein self-association in non-glycosylated Thermomyces lanuginosus lipase based on crystal lattice contacts

2015 ◽  
Vol 1854 (12) ◽  
pp. 1914-1921 ◽  
Author(s):  
Jens Kvist Madsen ◽  
Thomas Rebsdorf Sørensen ◽  
Jørn Døvling Kaspersen ◽  
Maria Berggård Silow ◽  
Jesper Vind ◽  
...  
Keyword(s):  
Crystal Lattice ◽  
Thermomyces Lanuginosus ◽  
Thermomyces Lanuginosus Lipase ◽  
Self Association

Adsorption of Benzene from Aqueous Solution Using Base Modified Expanded Perlite

2012 ◽  
Vol 622-623 ◽  
pp. 1779-1783
Author(s):  
Richard Appiah-Ntiamoah ◽  
Xuan Thang Mai ◽  
Francis W.Y. Momade ◽  
Hern Kim
Keyword(s):  
Zeta Potential ◽  
Adsorption Capacity ◽  
Linear Regression Analysis ◽  
Basic Medium ◽  
Maximum Adsorption Capacity ◽  
Hydroxyl Groups ◽  
Expanded Perlite ◽  
Oh Groups ◽  
Base Solution ◽  
Ph Range

In this study, the adsorption capacity of expanded perlite (EP) for benzene at low concentrations in water was investigated after EP was treated with sodium hydroxide (NaOH). IR spectra used to characterize the modified EP showed that there was no bonding between NaOH and the hydroxyl groups on the surface of EP. However, the NaOH provided a basic medium for negatively charged surface oxide ions (-SO-) to form on EP. This fact was corroborated by pH readings of the modification solution. This reduced in pH from 10 to 9 at the end of the reaction which indicated that the hydroxyl OH- groups on the EP underwent deprotonation and hence releases H+ into the solution, and also positive sites on EP adsorbed OH- ions from the base solution. Mahir et al. in their paper Zeta potential of unexpanded and expanded perlite samples in various electrolyte media confirmed that EP has no isoelectric point and exhibits negative zeta potential in the pH range of 2-11. The surface oxides (-SO-) were believed to have given EP it adsorptive potential. Adsorption isotherm values correlated reasonably well with the Langmuir isotherm model and it parameters (qo and K) were obtained using linear regression analysis. A maximum adsorption capacity (qo) value of 19.42 mg/g was achieved.

scholarly journals Production of Structured Phosphatidylcholine with High Content of Myristic Acid by Lipase-Catalyzed Acidolysis and Interesterification

Catalysts ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 281 ◽  
Author(s):  
Anna Chojnacka ◽  
Witold Gładkowski
Keyword(s):  
Myristic Acid ◽  
Rhizomucor Miehei ◽  
Egg Yolk ◽  
Thermomyces Lanuginosus ◽  
Molar Ratio ◽  
Acyl Donor ◽  
Thermomyces Lanuginosus Lipase ◽  
Screening Experiments ◽  
Miehei Lipase ◽  
Acyl Donors

Synthesis of structured phosphatidylcholine (PC) enriched with myristic acid (MA) was conducted by acidolysis and interesterification reactions using immobilized lipases as catalysts and two acyl donors: trimyristin (TMA) isolated from ground nutmeg, and myristic acid obtained by saponification of TMA. Screening experiments indicated that the most effective biocatalyst for interesterification was Rhizomucor miehei lipase (RML), whereas for acidolysis, the most active were Thermomyces lanuginosus lipase (TLL) and RML. The effect of the molar ratio of substrates (egg-yolk PC/acyl donor), enzyme loading, and different solvent on the incorporation of MA into PC and on PC recovery was studied. The maximal incorporation of MA (44 wt%) was achieved after 48 h of RML-catalyzed interesterification in hexane using substrates molar ratio (PC/trimyristin) 1/5 and 30% enzyme load. Comparable results were obtained in toluene with 1/3 substrates molar ratio. Interesterification of PC with trimyristin resulted in significantly higher MA incorporation than acidolysis with myristic acid, particularly in the reactions catalyzed by RML.

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