The nuclear Overhauser enhancement of the carbon-13 magnetic resonance spectrum of formic acid

Kuhlmann, Karl; Grant, David M.

doi:10.1021/ja01028a038

Cited by 115 publications

(36 citation statements)

References 1 publication

(2 reference statements)

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“…The NMR experiments were realized using a single pulse detection of carbon with power-gated 1 H decoupling. The 90°carbon pulse was set to 11.25 s, micro second and a proton decoupling (WALTZ16) of 3 kHz was applied during acquisition (1.25 s) but also during the recycle delay (5 s) to gain signal by nuclear Overhauser enhancement (34). Each NMR experiment was realized at 298 K with 5,000 scans.…”

Section: Methodsmentioning

confidence: 99%

Specific Adduction of Plant Lipid Transfer Protein by an Allene Oxide Generated by 9-Lipoxygenase and Allene Oxide Synthase

Bakan

Hámberg

Perrocheau

et al. 2006

Journal of Biological Chemistry

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Lipid transfer proteins (LTPs) are ubiquitous plant lipidbinding proteins that have been associated with multiple developmental and stress responses. Although LTPs typically bind fatty acids and fatty acid derivatives in a non-covalent way, studies on the LTPs of barley seeds have identified an abundantly occurring covalently modified form, LTP1b, the lipid ligand of which has resisted clarification. In the present study, this adduct was identified as the ␣-ketol 9-hydroxy-10-oxo-12(Z)-octadecenoic acid. Further studies on the formation of LTP1b demonstrated that the ligand was introduced by nucleophilic attack of the free carboxylate group of the Asp-7 residue of the protein at carbon-9 of the allene oxide fatty acid 9(S),10-epoxy-10,12(Z)-octadecadienoic acid. This reactive oxylipin was produced in barley seeds by oxygenation of linoleic acid by 9-lipoxygenase followed by dehydration of the resulting hydroperoxide by allene oxide synthase. The generation of protein-oxylipin adducts represents a new function for plant allene oxide synthases, enzymes that have earlier been implicated mainly in the biosynthesis of the jasmonate family of plant hormones. Additionally, the LTP-allene oxide synthase interaction opens new perspectives regarding the roles of LTPs in the signaling of plant defense and development.

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Section: Methodsmentioning

confidence: 99%

Specific Adduction of Plant Lipid Transfer Protein by an Allene Oxide Generated by 9-Lipoxygenase and Allene Oxide Synthase

Bakan

Hámberg

Perrocheau

et al. 2006

Journal of Biological Chemistry

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“…The NMR experiments were realized in DMSO-d 6 using a single pulse detection of carbon with power-gated 1 H decoupling. The 90°carbon pulse was set to 11.25 ls and a proton decoupling (WALTZ16) of 3 kHz was applied during acquisition (1.25 s) but also during the recycle delay (5 s) in order to gain signal by nuclearoverhauser enhancement (NOE; Kuhlmann and Grant 1968). Each NMR experiment was realized at 313 K with 22 K scans and calibration of the carbon chemical shifts were realised using the carbon signal of DMSO as an internal reference.…”

Section: Nmr Spectroscopymentioning

confidence: 99%

Studies of xylan interactions and cross-linking to synthetic lignins formed by bulk and end-wise polymerization: a model study of lignin carbohydrate complex formation

Barakat

Winter²,

Rondeau-Mouro

et al. 2007

Planta

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The mechanism of lignin carbohydrate complex formation by addition of polysaccharides on quinone methide (QM) generated during lignin polymerisation was investigated using a model approach. Dehydrogenation polymers (DHPs, lignin model compounds) were synthesized from coniferyl alcohol in the presence of a glucuronoarabinoxylan (GAX) extracted from oat spelts, by Zutropfverfahren (ZT) and Zulaufverfahren (ZL) methods. The methods ZT and ZL differed in their distribution of QM over the reaction period but generated roughly the same QM amount. Steric exclusion chromatography of the ZT and ZL reaction products showed that only the ZT reaction produced high molar mass compounds. Covalent linkages in the ZT reaction involving ether bonds between GAX moiety and alpha carbon of the lignin monomer were confirmed by (13)C NMR and xylanase-based fractionation. The underlying phenomena were further investigated by examining the interactions between GAX and DHP in sorption experiments. GAX and DHPs were shown to interact to form hydrophobic aggregates. In the ZT process, slow addition permitted polymer reorganisation which led to dehydration around the lignin-like growing chains thereby limiting the addition of water on the quinone methide formed during polymerisation and thus favoured lignin-carbohydrate complex (LCC) formation.

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“…The single pulse detection using the HRMAS probe used a 6 s 90 • carbon pulse with a proton decoupling (WALTZ16) of 3KHz applied during acquisition (1.6 s) but also during the recycle delay (2 s) in order to gain signal by nuclear overhauser enhancement (NOE) [46]. Assignment of the menthone and linalool carbons were first performed using carbon single pulse detection without proton decoupling to determine the carbons multiplicity.…”

Section: Nmrmentioning

confidence: 99%

Structural investigation of amylose complexes with small ligands: inter- or intra-helical associations?

Rondeau-Mouro

Bail

Buléon

2004

International Journal of Biological Macromolecules

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The nuclear Overhauser enhancement of the carbon-13 magnetic resonance spectrum of formic acid

Cited by 115 publications

References 1 publication

Specific Adduction of Plant Lipid Transfer Protein by an Allene Oxide Generated by 9-Lipoxygenase and Allene Oxide Synthase

Specific Adduction of Plant Lipid Transfer Protein by an Allene Oxide Generated by 9-Lipoxygenase and Allene Oxide Synthase

Studies of xylan interactions and cross-linking to synthetic lignins formed by bulk and end-wise polymerization: a model study of lignin carbohydrate complex formation

Structural investigation of amylose complexes with small ligands: inter- or intra-helical associations?

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