Efficient Hydrolytic Breakage of β-1,4-Glycosidic Bond Catalyzed by a Difunctional Magnetic Nanocatalyst

2018 ◽  
Vol 71 (8) ◽  
pp. 559 ◽  
Author(s):  
Ren-Qiang Yang ◽  
Ni Zhang ◽  
Xiang-Guang Meng ◽  
Xiao-Hong Liao ◽  
Lu Li ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Reaction Time ◽  
Microcrystalline Cellulose ◽  
Significant Loss ◽  
Reducing Sugar ◽  
Magnetic Nanocatalyst ◽  
Efficient Catalyst ◽  
Glycosidic Bonds ◽  
Hydrolysis Of Cellulose ◽  
Hydrolysis Of

A novel difunctional magnetic nanocatalyst (DMNC) was prepared and used to catalyse the hydrolytic breakage of β-1,4-glycosidic bonds. The functional nanoparticle displayed excellent catalytic activity for hydrolysis of cellobiose to glucose under moderate conditions. The conversion of cellobiose and yield of glucose could reach 95.3 and 91.1 %, respectively, for a reaction time of 6 h at pH 4.0 and 130°C. DMNC was also an efficient catalyst for the hydrolysis of cellulose: 53.9 % microcrystalline cellulose was hydrolyzed, and 45.7 % reducing sugar was obtained at pH 4.0 and 130°C after 10 h. The magnetic catalyst could be recycled and reused five times without significant loss of catalytic activity.

Immobilized Nanoparticles-Mediated Enzymatic Hydrolysis of Cellulose for Clean Sugar Production: A Novel Approach

2019 ◽  
Vol 15 (3) ◽  
pp. 296-303 ◽  
Author(s):  
Swapnil Gaikwad ◽  
Avinash P. Ingle ◽  
Silvio Silverio da Silva ◽  
Mahendra Rai
Keyword(s):  
Catalytic Activity ◽  
Enzymatic Hydrolysis ◽  
Immobilized Enzyme ◽  
Free Enzyme ◽  
Magnetic Nanomaterials ◽  
Sugar Production ◽  
Cellulase Enzyme ◽  
Enzymatic Hydrolysis Of Cellulose ◽  
Hydrolysis Of Cellulose ◽  
Hydrolysis Of

Background: Enzymatic hydrolysis of cellulose is an expensive approach due to the high cost of an enzyme involved in the process. The goal of the current study was to apply magnetic nanomaterials as a support for immobilization of enzyme, which helps in the repeated use of immobilized enzyme for hydrolysis to make the process cost-effective. In addition, it will also provide stability to enzyme and increase its catalytic activity. Objective: The main aim of the present study is to immobilize cellulase enzyme on Magnetic Nanoparticles (MNPs) in order to enable the enzyme to be re-used for clean sugar production from cellulose. Methods: MNPs were synthesized using chemical precipitation methods and characterized by different techniques. Further, cellulase enzyme was immobilized on MNPs and efficacy of free and immobilized cellulase for hydrolysis of cellulose was evaluated. Results: Enzymatic hydrolysis of cellulose by immobilized enzyme showed enhanced catalytic activity after 48 hours compared to free enzyme. In first cycle of hydrolysis, immobilized enzyme hydrolyzed the cellulose and produced 19.5 ± 0.15 gm/L of glucose after 48 hours. On the contrary, free enzyme produced only 13.7 ± 0.25 gm/L of glucose in 48 hours. Immobilized enzyme maintained its stability and produced 6.15 ± 0.15 and 3.03 ± 0.25 gm/L of glucose in second and third cycle, respectively after 48 hours. Conclusion: This study will be very useful for sugar production because of enzyme binding efficiency and admirable reusability of immobilized enzyme, which leads to the significant increase in production of sugar from cellulosic materials.

The Formation of Plasma Acid at Atmospheric Pressure and its Application in Hydrolysis of Microcrystalline Cellulose

2013 ◽  
Vol 750-752 ◽  
pp. 1626-1629
Author(s):  
Bo Yuan ◽  
Ying Wang ◽  
Ying Chao Ji ◽  
Qiu Hong Wang
Keyword(s):  
Microcrystalline Cellulose ◽  
Atmospheric Pressure ◽  
High Performance ◽  
Barrier Discharge ◽  
Ph Value ◽  
Reducing Sugar ◽  
Dielectric Barrier ◽  
Integrated Optical ◽  
Hydrolysis Of ◽  
Single Factor Experiment

In this paper, plasma acid was obtained by treating distilled water with dielectric barrier discharge at atmospheric pressure in order to hydrolyze cellulose. The acidity of plasma acid was studied through a single factor experiment. A plasma acid with pH value of 1.42 was obtained and used to hydrolyze microcrystalline cellulose at 80°C for 60min. Under this condition, the integrated optical density (IOD) of the hydrolysis sample was 0.589. Based on standard glucose curve, the total reducing sugar (TRS) was calculated to be 53.75mg and the TRS yield was 53.75%. The filtrate was evaporated to get the solid hydrolysis sample to be analyzed by High-performance liquid chromatography (HPLC). The results showed that the sample mainly consisted of glucose, which proved that microcrystalline cellulose could be hydrolyzed by plasma acid. Therefore, it could be concluded that it was an environmentally friendly and economical method to hydrolyze the microcrystalline cellulose by plasma acid.

scholarly journals Bleaching of Microcrystalline Cellulose Produced by Gas-Phase Hydrolysis

2021 ◽  
pp. 173-183
Author(s):  
Alexander I. Sizov ◽  
◽  
Sergey D. Pimenov ◽  
Anastasia D. Stroiteleva ◽  
Katherine D. Stroiteleva ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Pharmaceutical Industry ◽  
Gas Phase ◽  
Sodium Hypochlorite ◽  
Microcrystalline Cellulose ◽  
High Rate ◽  
Subsequent Formation ◽  
Hydrolysis Of Cellulose ◽  
Yellow Tint ◽  
Hydrolysis Of

One of the main consumers of microcrystalline cellulose (MCC) is the pharmaceutical industry, where MCC is used as a binder and filler in direct compression of tablets. MCC is produced by acidic hydrolysis of cellulose, which usually results in a decrease in whiteness. This is due to the destruction of sugars formed during hydrolysis and the subsequent formation of colored products. The composition and properties of these products depend on the method of hydrolysis, acid concentration, temperature, and process duration. One of the most promising methods for producing MCC is gas-phase hydrolysis of cellulose with hydrogen chloride gas-air mixtures. The method has a high rate of hydrolysis, low reagent and energy consumption. The requirements of the pharmaceutical industry determine the need to produce MCC with high whiteness. The research purpose is to select bleaching modes for MCC using sodium hypochlorite and hydrogen peroxide as bleaching agents. MCC produced by gas-phase hydrolysis of bleached wood pulp was used during the study. The whiteness and intensity of the yellow tint of MCC in the bleaching process were determined by digital colorimetry on a flatbed scanner. The paper shows that sodium hypochlorite and hydrogen peroxide allow achieving the whiteness not less than 90 % and the intensity of the yellow tint not more than 3 standard units. High-quality bleaching can be carried out even for MCC samples with an initial whiteness of about 40 %. The most effective bleaching agent is sodium hypochlorite when the pH of the bleaching solution is 2–3. Hydrogen peroxide also provides high whiteness of MCC at pH of 10–11. However, the consumption of active oxygen (AO) for bleaching is more than three times higher in comparison with the consumption of active chlorine (ACh). It was found that the dyes of MCC produced by gas-phase hydrolysis consist of two chromophore groups that decolorize at different rates. The easily oxidized group of components makes up about 90 % of the total amount of dyes, and the resistant to oxidation components make up about 10 % and determine the intensity of the yellow tint of MCC. The modes of bleaching MCC with sodium hypochlorite and hydrogen peroxide to product samples with whiteness comparable to that of imported samples were determined. For citation: Sizov A.I., Pimenov S.D., Stroiteleva A.D., Stroiteleva K.D. Bleaching of Microcrystalline Cellulose Produced by Gas-Phase Hydrolysis. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 6, pp. 173–183. DOI: 10.37482/0536-1036-2021-6-173-183

scholarly journals One-pot three-component tandem annulation of 4-hydroxycoumarine with aldehyde and aromatic amines using graphene oxide as an efficient catalyst

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rabindranath Singha ◽  
Aminul Islam ◽  
Pranab Ghosh
Keyword(s):  
Graphene Oxide ◽  
Catalytic Activity ◽  
Aromatic Amines ◽  
Significant Loss ◽  
Solvent Free ◽  
One Pot ◽  
Efficient Catalyst ◽  
New Class ◽  
Broad Scope ◽  
Plausible Mechanism

AbstractA convenient and efficient solvent-free, facile, one-pot three-component graphene oxide catalysed approach has been described for the synthesis of chromeno-[4,3-b]quinolin-6-one derivatives from 4-hydroxycoumarin with aldehydes and aromatic amines. Graphene oxide (GO) has proved to be a new class of heterogeneous carbocatalyst which could be easily recovered and reused up to 5th run without significant loss of its catalytic activity. A broad scope of substrate applicability is offered and a plausible mechanism is also suggested for this developed protocol.

Hydrolysis of cellulose into reducing sugar via hot-compressed ethanol/water mixture

2012 ◽  
Vol 42 ◽  
pp. 143-150 ◽  
Author(s):  
Cunwen Wang ◽  
Fanglei Zhou ◽  
Zhao Yang ◽  
Weiguo Wang ◽  
Faquan Yu ◽  
...  
Keyword(s):  
Reducing Sugar ◽  
Water Mixture ◽  
Hydrolysis Of Cellulose ◽  
Hydrolysis Of

scholarly journals Bioethanol Production from Paper Fibre Residue Using Diluted Alkali Hydrolysis and the Fermentation Process

2011 ◽  
Vol 8 (4) ◽  
pp. 1951-1957 ◽  
Author(s):  
G. Sathya Geetha ◽  
A. Navaneetha Gopalakrishnan
Keyword(s):  
Reaction Time ◽  
Penicillium Chrysogenum ◽  
Ethanol Concentration ◽  
Ethanol Yield ◽  
Bioethanol Production ◽  
Time Period ◽  
Hydrolysis Of Cellulose ◽  
Alkali Hydrolysis ◽  
Hydrolysis Of ◽  
State Of Art

The state of art for the bioethanol production from paper fibre residue using diluted alkali hydrolysis and fermentation processes was evaluated. Hydrolysis of paper fibre residue with diluted sodium hydroxide at various time period, temperature and concentration were investigated. The paper fibre residue was pre-steamed, impregnated with diluted NaOH (0 to 25%) and subsequently hydrolyzed in a reactor at temperatures that ranged between 30 to 50oC, for reaction time between 30 minutes to 150 minutes. The highest yield of monosaccharide (indicating the efficient hydrolysis of cellulose and hemi cellulose) was found at a temperature of 35oC for a reaction time of 90 minutes. Fermentability of hemicelluloses hydrolysate was tested using monosaccharide fermenting microorganismPenicillium chrysogenumandSaccharomyces cereviacea. The fermentability of the hydrolysate decreased strongly for hydrolysate produced at temperature higher than 50oC. The ethanol concentration of monosaccharide hydrolysate was found to be 34.06 g/L and the ethanol yield was 0.097 g/g.

scholarly journals Friedel-Crafts acetylation of indole, 5-methoxyindole and 5-chloroindole using copper triflate under microwave irradiation

2016 ◽  
Vol 19 (4) ◽  
pp. 177-184
Author(s):  
Hai Truong Nguyen ◽  
Phuong Hoang Tran
Keyword(s):  
Catalytic Activity ◽  
Acetic Anhydride ◽  
Microwave Irradiation ◽  
Organic Synthesis ◽  
Significant Loss ◽  
Indole Derivatives ◽  
Efficient Catalyst ◽  
Acidic Catalyst ◽  
Mild Conditions

Friedel-Crafts acetylation is an important reaction in organic synthesis processes. Acetylation of indole derivatives with acetic anhydride as acylating reagent using Cu(OTf)2 as a catalyst has been investigated under microwave irradiation. Different from traditional Lewis acidic catalyst, Cu(OTf)2 was found to be an efficient catalyst for Friedel-Crafts acetylation of indoles under mild conditions. Moreover, Cu(OTf)2 was safe-to-handle, recovered and reused several times without significant loss of catalytic activity.

scholarly journals Study of the mode of action and site-specificity of the endo-(1→4)-β-d-glucanases of the fungus Penicillium pinophilum with normal, 1-3H-labelled, reduced and chromogenic cello-oligosaccharides

1990 ◽  
Vol 266 (2) ◽  
pp. 371-378 ◽  
Author(s):  
K M Bhat ◽  
A J Hay ◽  
M Claeyssens ◽  
T M Wood
Keyword(s):  
Cell Membrane ◽  
Mode Of Action ◽  
Analytical Data ◽  
Degree Of Polymerization ◽  
The Other ◽  
Site Specificity ◽  
Glycosidic Bonds ◽  
Penicillium Pinophilum ◽  
Hydrolysis Of Cellulose ◽  
Hydrolysis Of

The modes of action of the five major endo-(1→4)-beta-D-glucanases (I, II, III, IV and V) purified from Penicillium pinophilum cellulase were compared by h.p.l.c. analysis, with normal, 1-3H-labelled and reduced cello-oligosaccharides and 4-methylumbelliferyl glycosides as substrates. Significant differences were observed in the preferred site of cleavage even when substrates with the same number of glycosidic bonds were compared. Thus, although endoglucanase I was unable to attack normal cello-oligosaccharides shorter than degree of polymerization 6, it hydrolysed reduced cellopentaose to yield cellotriose and cellobi-itol, and it produced cellotriose and 4-methylumbelliferyl glucoside from 4-methylumbelliferyl cellotetraoside. Endoglucanase IV hydrolysed [1-3H]cellotriose but did not attack either cellotri-itol or 4-methylumbelliferyl cellobioside. These and other anomalous results indicated clearly that modification of the reducing glycosyl residue on the cello-oligosaccharides induces in an apparent change in the mode of action of the endoglucanases. It is suggested that, although cello-oligosaccharide derivatives are useful for differentiating and classifying endoglucanases, conclusions on the mechanism of cellulase action resulting from these measurements should be treated cautiously. Unequivocal information on the mode of endoglucanase action on cello-oligosaccharides was obtained with radiolabelled cello-oligosaccharides of degree of polymerization 3 to 5. Indications that transglycosylation was a property of the endoglucanases were particularly evident with the 4-methylumbelliferyl cello-oligosaccharides. Turnover numbers for hydrolysis of the umbelliferyl cello-oligosaccharides were calculated, and these, along with the other analytical data collected on the products of hydrolysis of the normal, reduced and radiolabelled cello-oligosaccharides, suggested that the various endoglucanases had different roles to play in the overall hydrolysis of cellulose to sugars small enough to be transported through the cell membrane.

Zirconium(IV) 4-sulphophenylethyliminobismethylphosphonate as an efficient and reusable catalyst for one-pot synthesis of 3,4-dihydropyrimidones under solvent-free conditions

2011 ◽  
Vol 65 (6) ◽  
Author(s):  
Xin-Bin Yang ◽  
Xiang-Kai Fu ◽  
Yu Huang ◽  
Ren-Quan Zeng
Keyword(s):  
Catalytic Activity ◽  
Elemental Analysis ◽  
Biginelli Reaction ◽  
Significant Loss ◽  
Solvent Free ◽  
Reusable Catalyst ◽  
One Pot ◽  
Efficient Catalyst ◽  
Solvent Free Conditions ◽  
Simple Filtration

AbstractZirconium(IV) 4-sulphophenylethyliminobismethylphosphonate (ZSBEDP) was prepared and characterised by elemental analysis, IR, TG-DSC, and XRD. ZSBEDP was found to be an efficient catalyst for the Biginelli reaction of aromatic aldehyde, ethyl acetoacetate, and urea or thiourea under solvent-free conditions so as to give 3,4-dihydropyrimidones in good to excellent yields. The catalyst can be separated by simple filtration and reused without significant loss of its catalytic activity.

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