Multistep degradation method for β-O-4 linkage in lignins: γ-TTSA method. Part 2: reaction of lignin model polymer (DHP)

Holzforschung ◽  
2013 ◽  
Vol 67 (3) ◽  
pp. 249-256 ◽  
Author(s):  
Daisuke Ando ◽  
Fumiaki Nakatsubo ◽  
Toshiyuki Takano ◽  
Hiroshi Nishimura ◽  
Masato Katahira ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Quantum Coherence ◽  
Heteronuclear Single Quantum Coherence ◽  
Single Quantum ◽  
Polymer Model ◽  
Reaction Step ◽  
Ft Ir ◽  
Lignin Model ◽  
Dehydrogenation Polymer ◽  
Ft Ir Spectroscopy

Abstract A selective cleavage method for β-O-4 linkages (the γ-TTSA method) was introduced in previous works, which consists of four reaction steps: (1) γ-tosylation, (2) thioetherification, (3) sulfonylation, and (4) mild alkali degradation. This method was applied to the degradation of a lignin polymer model (dehydrogenation polymer, DHP) consisting of guaiacyl units. Each reaction step was followed by Fourier transform infrared (FT-IR) spectroscopy and heteronuclear single quantum coherence nuclear magnetic resonance (HSQC-NMR) spectroscopy. It was demonstrated that only the β-O-4 linkage was selectively cleaved by the γ-TTSA method, although other linkages, such as β-5 and β-β linkages, were also present in the DHP. Consequently, the γ-TTSA method is expected to be also useful for the degradation of native lignins.

scholarly journals Isolation of an isoflavonoid and a terpenoid from the heartwood of Baphia nitida Lodd. (camwood)

2020 ◽  
Vol 31 (1) ◽  
pp. 5-8
Author(s):  
Gloria Ihuoma Ndukwe ◽  
Amarachi Oluah ◽  
Godswill Kuta Fekarurhobo
Keyword(s):  
Quantum Coherence ◽  
Methanolic Extract ◽  
Ultra Violet ◽  
Molecular Formula ◽  
Heteronuclear Single Quantum Coherence ◽  
Violet Light ◽  
Nmr Techniques ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

AbstractChromatographic separation of methanolic extract of Baphia nitida heartwood gave two crystalline solids characterized as 3,9-dimethoxy-6aR,11aR-dihydro-6H-benzofuro(3,2-C)[1]benzopyran (also known as homopterocarpin) with molecular formula C17H16O4 (1.57% yield) and 2,4-dimethoxybenzaldehyde C9H10O3 (2.27% yield). Each of the isolated compounds showed a single spot on developed thin layer chromatographic plate under ultra-violet light (254 nm) and spray reagent (10% sulfuric acid in methanol solution). Structural elucidation was achieved using Fourier transform infrared (FT-IR) spectroscopy, one and two-dimension nuclear magnetic resonance (NMR) techniques. Distortionless enhancement by polarization transfer-edited-heteronuclear single quantum coherence (DEPT-ed-HSQC) was also a useful tool that aided the characterization of the two secondary metabolites isolated from Baphia nitida heartwood.

scholarly journals Establishing lignin structure-upgradeability relationships using quantitative 1H–13C heteronuclear single quantum coherence nuclear magnetic resonance (HSQC-NMR) spectroscopy

2019 ◽  
Vol 10 (35) ◽  
pp. 8135-8142 ◽  
Author(s):  
Masoud Talebi Amiri ◽  
Stefania Bertella ◽  
Ydna M. Questell-Santiago ◽  
Jeremy S. Luterbacher
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Quantum Coherence ◽  
Heteronuclear Single Quantum Coherence ◽  
Single Quantum ◽  
Nmr Method ◽  
Nuclear Magnetic ◽  
Lignin Structure

By using a quantitative HSQC-NMR method to measure chemical functionalities within the structure of isolated lignin samples, lignin's upgradability can be very precisely predicted.

scholarly journals N-[7-Chloro-4-[4-(phenoxymethyl)-1H-1,2,3-triazol-1-yl] quinoline]-acetamide

Molbank ◽  
10.3390/m1213 ◽  
2021 ◽  
Vol 2021 (2) ◽  
pp. M1213
Author(s):  
Paolo Coghi ◽  
Jerome P. L. Ng ◽  
Ali Adnan Nasim ◽  
Vincent Kam Wai Wong
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Quantum Coherence ◽  
Biologically Active ◽  
Proton Nuclear Magnetic Resonance ◽  
Dipolar Cycloaddition ◽  
Heteronuclear Single Quantum Coherence ◽  
Pharmacokinetic Properties ◽  
Nuclear Magnetic

The 1,2,3-triazole is a well-known biologically active pharmacophore constructed by the copper-catalyzed azide–alkyne cycloaddition. We herein reported the synthesis of 4-amino-7-chloro-based [1,2,3]-triazole hybrids via Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition of 4-azido-7-chloroquinoline with an alkyne derivative of acetaminophen. The compound was fully characterized by Fourier-transform infrared (FTIR), proton nuclear magnetic resonance (1H-NMR), carbon-13 nuclear magnetic resonance (13C-NMR), heteronuclear single quantum coherence (HSQC), ultraviolet (UV) and high-resolution mass spectroscopies (HRMS). This compound was screened in vitro with different normal and cancer cell lines. The drug likeness of the compound was also investigated by predicting its pharmacokinetic properties.

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