scholarly journals A commercial laccase-mediator system to delignify and improve saccharification of the fast-growing Paulownia fortunei (Seem.) Hemsl.

Holzforschung ◽  
2018 ◽  
Vol 73 (1) ◽  
pp. 45-54 ◽  
Author(s):  
Jorge Rencoret ◽  
Antonio Pereira ◽  
Gisela Marques ◽  
José Carlos del Río ◽  
Ángel T. Martínez ◽  
...  
Keyword(s):  
Lignin Content ◽  
Enzymatic Saccharification ◽  
2D Nmr ◽  
Syringic Acid ◽  
2D Nmr Spectroscopy ◽  
Fast Growing ◽  
Alkaline Peroxide ◽  
Syringyl Lignin ◽  
Methyl Syringate ◽  
Paulownia Wood

Abstract It was demonstrated for the first time that a laccase-based enzymatic pretreatment is able to delignify fast-growing paulownia species. The treatment was performed with a commercial low-redox potential laccase isolated from Myceliophthora thermophila (Apinis) Oorschot and methyl syringate (MeS) as a natural phenolic mediator. Up to 24% lignin removal was attained by the laccase-MeS treatment (L/MeS), followed by alkaline peroxide extraction in a multistage sequence. The reduction in lignin content was accompanied by a significant improvement in the subsequent enzymatic saccharification, with increases of up to 38% glucose and 34% xylose yields. The structural modifications of the lignin were analyzed in situ by two dimensional-nuclear magnetic resonance (2D-NMR) spectroscopy. A considerable removal of guaiacyl and syringyl lignin units with respect to the carbohydrate signals was visible as well as the cleavage of β-O-4′, β-5′ and β-β′ linkages leading to elevated amounts of Cα-oxidized guaiacyl and syringyl units. The presence of oxidized lignin compounds in the filtrates of the enzymatic treatments – such as vanillin, vanillic acid, syringaldehyde and syringic acid – conclusively demonstrates the ability of L/MeS treatment to oxidize and depolymerize the lignin in paulownia wood.

scholarly journals Valorization of Alkaline Peroxide Mechanical Pulp by Metal Chloride-Assisted Hydrotropic Pretreatment for Enzymatic Saccharification and Cellulose Nanofibrillation

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 331 ◽  
Author(s):  
Huiyang Bian ◽  
Xinxing Wu ◽  
Jing Luo ◽  
Yongzhen Qiao ◽  
Guigan Fang ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Lignocellulosic Biomass ◽  
Lignin Content ◽  
Enzymatic Saccharification ◽  
Fiber Surface ◽  
Cost Effective ◽  
Metal Chloride ◽  
Fractionation Process ◽  
Metal Chlorides ◽  
Alkaline Peroxide

Developing economical and sustainable fractionation technology of lignocellulose cell walls is the key to reaping the full benefits of lignocellulosic biomass. This study evaluated the potential of metal chloride-assisted p-toluenesulfonic acid (p-TsOH) hydrolysis at low temperatures and under acid concentration for the co-production of sugars and lignocellulosic nanofibrils (LCNF). The results indicated that three metal chlorides obviously facilitated lignin solubilization, thereby enhancing the enzymatic hydrolysis efficiency and subsequent cellulose nanofibrillation. The CuCl2-assisted hydrotropic pretreatment was most suitable for delignification, resulting in a relatively higher enzymatic hydrolysis efficiency of 53.2%. It was observed that the higher residual lignin absorbed on the fiber surface, which exerted inhibitory effects on the enzymatic hydrolysis, while the lower lignin content substrates resulted in less entangled LCNF with thinner diameters. The metal chloride-assisted rapid and low-temperature fractionation process has a significant potential in achieving the energy-efficient and cost-effective valorization of lignocellulosic biomass.

Demonstration of 2D NMR Spectroscopy in a Powered Magnet at 25 T Using Cascade Field Regulation

2019 ◽  
Author(s):  
Benjamin D. McPheron ◽  
Jeffrey L. Schiano ◽  
Brian F. Thomson ◽  
Kiran K. Shetty ◽  
William W. Brey
Keyword(s):  
Nmr Spectroscopy ◽  
2D Nmr ◽  
2D Nmr Spectroscopy

scholarly journals 5-((8-Hydroxyquinolin-5-yl)diazenyl)-3-methyl-1H-pyrazole-4-carboxylic Acid

Molbank ◽  
10.3390/m1238 ◽  
2021 ◽  
Vol 2021 (2) ◽  
pp. M1238
Author(s):  
Ion Burcă ◽  
Valentin Badea ◽  
Calin Deleanu ◽  
Vasile-Nicolae Bercean
Keyword(s):  
Chemical Structure ◽  
Functional Group ◽  
Coupling Reaction ◽  
2D Nmr ◽  
Azo Coupling ◽  
2D Nmr Spectroscopy ◽  
Azo Compound ◽  
Ft Ir ◽  
New Compounds ◽  
Carboxylic Functional Group

A new azo compound was prepared via the azo coupling reaction between 4-(ethoxycarbonyl)-3-methyl-1H-pyrazole-5-diazonium chloride and 8-hydroxyquinoline (oxine). The ester functional group of the obtained compound was hydrolyzed and thus a new chemical structure with a carboxylic functional group resulted. The structures of the new compounds were fully characterized by: UV–Vis, FT-IR, 1D and 2D NMR spectroscopy, and HRMS spectrometry.

scholarly journals Ambient-Temperature Synthesis of (E)-N-(3-(tert-Butyl)-1-methyl-1H-pyrazol-5-yl)-1-(pyridin-2-yl)methanimine

Molbank ◽  
10.3390/m1250 ◽  
2021 ◽  
Vol 2021 (3) ◽  
pp. M1250
Author(s):  
Diana Becerra ◽  
Justo Cobo ◽  
Juan-Carlos Castillo
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
Ambient Temperature ◽  
Magnesium Sulfate ◽  
Elemental Analysis ◽  
Condensation Reaction ◽  
2D Nmr ◽  
2D Nmr Spectroscopy ◽  
Temperature Synthesis ◽  
Tert Butyl

We report the ambient-temperature synthesis of novel (E)-N-(3-(tert-butyl)-1-methyl-1H-pyrazol-5-yl)-1-(pyridin-2-yl)methanamine 3 in 81% yield by a condensation reaction between 3-(tert-butyl)-1-methyl-1H-pyrazol-5-amine 1 and 2-pyridinecarboxaldehyde 2 in methanol using magnesium sulfate as a drying agent. The N-pyrazolyl imine 3 was full characterized by IR, 1D, and 2D NMR spectroscopy, mass spectrometry, and elemental analysis.

Highly NIR-emitting ytterbium complexes containing 2-(tosylaminobenzylidene)-N-benzoylhydrazone anions: structure in solution and use for bioimaging

2021 ◽  
Author(s):  
Anton D Kovalenko ◽  
Alexander A. Pavlov ◽  
Ilya D. Ustinovich ◽  
Alena S. Kalyakina ◽  
Alexander S Goloveshkin ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Lanthanide Complexes ◽  
2D Nmr ◽  
2D Nmr Spectroscopy ◽  
Ytterbium Complexes ◽  
Solution Behaviour ◽  
Structure In Solution

Abstract: Solution behaviour in DMSO using 1D and 2D NMR spectroscopy was performed for lanthanide complexes Ln(L)(HL) and Ln(HL)2Cl, containing non-macrocyclic 2-(tosylamino)-benzylidene-N-benzoylhydrazone (H2L), and the structure of [Yb(L)]+ cation in...

scholarly journals ent-Kaurane Diterpenes from Annona glabra and Their Cytotoxic Activities

2014 ◽  
Vol 9 (12) ◽  
pp. 1934578X1400901
Author(s):  
Hoang Le Tuan Anh ◽  
Nguyen Thi Thu Hien ◽  
Dan Thi Thuy Hang ◽  
Tran Minh Ha ◽  
Nguyen Xuan Nhiem ◽  
...  
Keyword(s):  
Cell Lines ◽  
Cancer Cell ◽  
Human Cancer ◽  
2D Nmr ◽  
Cancer Cell Lines ◽  
Cytotoxic Activities ◽  
Human Cancer Cell ◽  
2D Nmr Spectroscopy ◽  
Human Cancer Cell Lines ◽  
Annona Glabra

A new ent-kaurane glycoside, annoglabasin H (1), and three known ent-kauranes, annoglabasin E (2), annoglabasin B (3), and 19-nor- ent-kaurent-4-ol-17-oic acid (4) were isolated from the fruits of Annona glabra. Their structures were determined by the combination of spectroscopic and chemical methods, including 1D- and 2D-NMR spectroscopy, as well as by comparison with the NMR data reported in the literature. The cytotoxic activities of these compounds were evaluated on four human cancer cell lines, LU-1, MCF-7, SK-Mel2, and KB. Compound 1 exhibited significant cytotoxic activity on all tested human cancer cell lines with IC50 values ranging from 3.7 to 4.6 μM.

scholarly journals NMR-Based Structural Characterization of a Two-Disulfide-Bonded Analogue of the FXIIIa Inhibitor Tridegin: New Insights into Structure–Activity Relationships

2021 ◽  
Vol 22 (2) ◽  
pp. 880
Author(s):  
Thomas Schmitz ◽  
Ajay Abisheck Paul George ◽  
Britta Nubbemeyer ◽  
Charlotte A. Bäuml ◽  
Torsten Steinmetzer ◽  
...  
Keyword(s):  
Structural Information ◽  
Coagulation Factor ◽  
Md Simulations ◽  
2D Nmr ◽  
Label Free ◽  
2D Nmr Spectroscopy ◽  
Structure Information ◽  
Structure Activity Relationships ◽  
Structure Activity ◽  
Blood Sucking

The saliva of blood-sucking leeches contains a plethora of anticoagulant substances. One of these compounds derived from Haementeria ghilianii, the 66mer three-disulfide-bonded peptide tridegin, specifically inhibits the blood coagulation factor FXIIIa. Tridegin represents a potential tool for antithrombotic and thrombolytic therapy. We recently synthesized two-disulfide-bonded tridegin variants, which retained their inhibitory potential. For further lead optimization, however, structure information is required. We thus analyzed the structure of a two-disulfide-bonded tridegin isomer by solution 2D NMR spectroscopy in a combinatory approach with subsequent MD simulations. The isomer was studied using two fragments, i.e., the disulfide-bonded N-terminal (Lys1–Cys37) and the flexible C-terminal part (Arg38–Glu66), which allowed for a simplified, label-free NMR-structure elucidation of the 66mer peptide. The structural information was subsequently used in molecular modeling and docking studies to provide insights into the structure–activity relationships. The present study will prospectively support the development of anticoagulant-therapy-relevant compounds targeting FXIIIa.

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