ChemInform Abstract: FIRST DETERMINATION OF THE STRUCTURE OF AN ION-PAIRED SPECIES IN NONPOLAR MEDIA: HYDROGEN-1, CARBON-13, LITHIUM-7 NMR SPECTRA OF PERALKYLCYCLOHEXADIENYL LITHIUM COMPOUNDS

rel(1S,4S,5R)-3,3,5-Trimethyl-4-[( 1E)-3-oxo-1-butenyl]-4,5-epoxy-cyclohexyl-O-β-D-glucopyranoside (I) was isolated from the aerial part of Veratrum lobelianum BERNH. The structure was derived mainly from detailed analysis of 1H and 13C NMR spectra of its acetylated derivative II. Compound I has been already reported under the name icariside B2in Epimedium grandiflorum MORR. var. thunbergianum (MIQ.) NAKAI.

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The use of13C satellites in the proton NMR spectra of oriented systems for the determination of molecular structure

Magnetic Resonance in Chemistry ◽

10.1002/mrc.1260240312 ◽

1986 ◽

Vol 24 (3) ◽

pp. 247-250

Author(s):

N. Suryaprakash ◽

C. L. Khetrapal

Keyword(s):

Molecular Structure ◽

Nmr Spectra ◽

Proton Nmr

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ChemInform Abstract: DETERMINATION OF ACTIVATION PARAMETERS OF SPIRONORCARADIENE-SPIROCYCLOHEPTATRIENE EQUILIBRIUMS BY LINE SHAPE ANALYSIS OF PROTON AND CARBON-13 NMR SPECTRA

Chemischer Informationsdienst ◽

10.1002/chin.197809103 ◽

1978 ◽

Vol 9 (9) ◽

Author(s):

M. KAUSCH ◽

H. DUERR

Keyword(s):

Shape Analysis ◽

Line Shape ◽

Nmr Spectra ◽

Activation Parameters ◽

Line Shape Analysis

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Structural characteristics of plant cell wall elucidated by solution-state 2D NMR spectroscopy with an optimized procedure

Green Processing and Synthesis ◽

10.1515/gps-2020-0049 ◽

2020 ◽

Vol 9 (1) ◽

pp. 650-663

Author(s):

Wanwan Wang ◽

Jibao Cai ◽

Zhenyu Xu ◽

Yi Zhang ◽

Fanchao Niu ◽

...

Keyword(s):

Cell Wall ◽

Quantum Coherence ◽

Nmr Spectra ◽

Plant Cell Wall ◽

Milling Time ◽

Structural Characteristics ◽

2D Nmr ◽

2D Nmr Spectroscopy ◽

Complete Representation

AbstractA method was developed for rapid qualitative determination of lignocellulose in the tobacco cell wall by utilizing 2D heteronuclear single quantum coherence NMR spectra (2D HSQC NMR). Traditional methods for analyzing the structure of lignocellulose involve many steps of separation and extraction, which is labor-intensive. In this work, the whole cell wall was milled and dissolved in deuterium solvent. The solvent dimethylsulfoxide (DMSO-d6) containing hexamethylphosphoramide (HMPA-d18) enhanced swelling of the sample and gave high-resolution spectra. The tobacco samples are ball milled at different ball milling times, and the state of the particles is observed through an electron microscope, and then the probability of the particles being less than 5 µm is counted. Through the comparison of the abundance and integration of the peak signals in the spectra under different transmittances, it was determined that when the milling time was 6 h, the quality of the NMR spectra was the best. The optimum conditions of characterizing tobacco structure were DMSO-d6/HMPA-d18 solution and 6 h milling time. Under these conditions, complete representation of the structure of lignocellulose and simplified process could be achieved.

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