N2 - A method for spatially three-dimensional (3D) localized two-dimensional (2D) 1H-13C correlation spectroscopy, localized HSQC, is proposed. T1 - 3D localized 1H-13C heteronuclear single-quantum coherence correlation spectroscopy in vivo The 3D localized 2D 1H-13C correlation spectra from a monkey brain in vivo were obtained after glucose injection, and amino acid metabolism was detected that is, glutamate appeared immediately after the injection, followed by the appearance of glutamate, glutamate, and glutamine. The localization capabilities of this method were confirmed in a phantom experiment. The preparation (echo) period 2τ can then be set substantially longer than 1/(2 1J(CH)), so that even in a whole-body system, slice-selective 90°(1H) pulses and gradient pulses can be applied in that period. The 180°(13C) and 180°(1H) pulses are separated in time, and the 180°(13C) pulse is applied at 1/(4 1J(CH)) before the 90°(1H) polarization transfer pulse. This method has the following special feature in the preparation period. (C) 2000 Wiley- Liss, Inc.Ībstract = "A method for spatially three-dimensional (3D) localized two-dimensional (2D) 1H-13C correlation spectroscopy, localized HSQC, is proposed. The 3D localized 2D 1H- 13C correlation spectra from a monkey brain in vivo were obtained after glucose injection, and amino acid metabolism was detected that is, glutamate appeared immediately after the injection, followed by the appearance of glutamate, glutamate, and glutamine. The preparation (echo) period 2τ can then be set substantially longer than 1/(2 1J(CH)), so that even in a whole-body system, slice-selective 90°( 1H) pulses and gradient pulses can be applied in that period. The 180°( 13C) and 180°( 1H) pulses are separated in time, and the 180°( 13C) pulse is applied at 1/(4 1J(CH)) before the 90°( 1H) polarization transfer pulse. Read more about how to correctly acknowledge RSC content.A method for spatially three-dimensional (3D) localized two-dimensional (2D) 1H- 13C correlation spectroscopy, localized HSQC, is proposed. Permission is not required) please go to the Copyright If you want to reproduce the wholeĪrticle in a third-party commercial publication (excluding your thesis/dissertation for which If you are the author of this article, you do not need to request permission to reproduce figuresĪnd diagrams provided correct acknowledgement is given. Provided correct acknowledgement is given. If you are an author contributing to an RSC publication, you do not need to request permission Please go to the Copyright Clearance Center request page. To request permission to reproduce material from this article in a commercial publication, Provided that the correct acknowledgement is given and it is not used for commercial purposes. This article in other publications, without requesting further permission from the RSC, Luterbacher,Ĭreative Commons Attribution-NonCommercial 3.0 Unported Licence. The accuracy of this model suggests that, unlike in native lignin, ether linkages no longer appear to be randomly distributed in isolated lignin.Įstablishing lignin structure-upgradeability relationships using quantitative 1H– 13C heteronuclear single quantum coherence nuclear magnetic resonance (HSQC-NMR) spectroscopy By using a simple ether cleavage model, we were able to predict final depolymerization yields very accurately (<4% error), conclusively demonstrating the direct causal relationship between ether content and lignin activity. We then prepared a range of isolated lignin samples with a wide range of ether contents (6–46%). Here, we demonstrated that a modified HSQC-NMR method known as HSQC 0 can accurately quantify lignin functionalities in extracted lignin using several synthetic polymer models. An obstacle to the development of a conclusive causal relationship between lignin structure and upgradeability has been the difficulty to quantitatively measure lignin structural features. Past studies have suggested that lignin structural features such as ether content are correlated to lignin's upgradeability. Lignin depolymerization could provide an attractive renewable aromatic feedstock for the chemical industry.
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