Nuclear magnetic resonance fingerprint

Rycroft et al. (1999) identihed the major components of plants from six locations in western Scotland and four from the Azores using nuclear magnetic resonance (NMR) fingerprinting and GC-MS. The terpene P-phellandrene [129], which may be responsible for the aroma of material crushed in the held, was detected in all specimens. The major components, which appear in Fig. 5.6, were shown to be methyl eveminate [444], the four methyl orcellinate derivatives [445 8], the two 9,10-dihydrophenanthrene derivatives [449] and [450], the newly described phthalide killamiensolide [451], and the bibenzyl [453]. Methyl eveminate was the major compound in all 10 specimens other compounds were more varied in their occurrence. Killamiensolide was not isolated as such but was detected when extracts were acetylated yielding, among other compounds, [452]. The presence of the bibenzyl compound [453] in more than trace amounts in P. killarniensis raises the possibility that it represents contamination from P. spinulosa with which it was growing at the one site. 

The main spectrometric identification techniques employed are gas chromatography/mass spectrometry (GC/MS) (13), liquid chromatography/tandem mass spectrometry (LC/MS(/MS)) (14), nuclear magnetic resonance (NMR) (11), and/or gas chromatography/Fourier transform infrared spectroscopy (GC/FL1R) (15). Each of these spectrometric techniques provides a spectrum that is characteristic of a chemical. MS and NMR spectra provide (detailed) structural information (like a fingerprint ), whereas an FUR spectrum provides information on functional groups. 

Nuclear Magnetic Resonance (NMR) spectroscopy is one of the most powerful analytical techniques in organic chemistry for elucidating the molecular structures of chemicals (1,2). Moreover, an NMR spectrum may be used like a fingerprint to identify a chemical by comparing it with its reference spectrum recorded from the authentic chemical under comparable conditions. The spectrum also reveals information on molecular conformation, isomerism, molecular dynamics, and diastereomers (3 6). 

The last two criteria, (4) and (5), are the most unequivocal and powerful signs for the formation of the hydrogen bond. A A-H) and IRa H bCKA—H))/ IRa h(KA—H)) are the most important characteristics of H-bonding, its fingerprints or signature [33], say literally. Proton nuclear magnetic resonance ( H NMR) chemical shifts in the A H- -B hydrogen bond are shifted downfield compared to the monomer,... 

Infrared (IR) and nuclear magnetic resonance (NMR) are valuable fingerprinting techniques for molecular compounds. They can also give information on new compounds about functional groups present and molecular symmetry. Visible/UV absorption spectroscopy and other techniques are usefiil for investigating electronic structure. 

Nuclear magnetic Resonance Absorption of radiation giving rise to transitions between different spin orientations of nuclei in a magnetic field N, P, G Sequences of biomacromolecules. Complete 3D structures. Unambiguous detection of certain functioned groups and information about the environment. Structural identification by fingerprinting. Studies of biomacromolecular interactions with ligemds. 

Fig. 7.32 Flowchart for generating nuclear magnetic resonance (NMR) fingerprints from chemical shift data...

Mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy are well-established techniques for the identification of chemical compounds. Both methods deliver unique fingerprints of molecules and, under the right conditions, they can also be used to quantify the concentration of a compound in a mixture, if not too many substances are present with spectra that show overlapping signals. Mostly the methods are used for pure substances, although and over recent decades, the techniques have particularly been used to study biomolecules such as peptides and proteins. For mixtures of, say, more than five compounds, an analytical separation method such as electrophoresis or chromatography is required to be able to identify or quantify the compounds. 

Ben H, Ragauskas AJ (2011) Heteronuclear single-quantum correlation-nuclear magnetic resonance (hsqc-nmr) fingerprint analysis of pyrolysis oils. Energy Fuels 25 2322-2332. doi 10.1021/ef2001162... 

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