2D NMR studies on muscle and cerebral metabolism in vivo

Tetrapyrazinoporphyrazine with peripheral menthol-thiophenyl substituents was synthesized using Linstead conditions and purified by flash column chromatography. The optimized synthetic and purification procedures allowed us to obtain a new macrocycle with 36% yield. Tetrapyrazinoporphyrazine derivative was characterized by UV–Vis and NMR spectroscopy, as well as MS spectrometry. Complex NMR studies using 1D and 2D NMR techniques allowed the analysis of the bulky menthol-thiophenyl substituted periphery of the new macrocycle. Further, photochemical stability and singlet oxygen quantum yield were determined by indirect method with diphenylisobenzofuran. The new tetrapyrazinoporphyrazine revealed low generation of singlet oxygen with a quantum yield of singlet oxygen formation at 2.3% in dimethylformamide. In turn, the macrocycle under irradiation with visible light presented very high stability with quantum yield for photostability of 9.59 × 10−6 in dimethylformamide, which figures significantly exceed the border for its classification as a stable porphyrinoid (10−4–10−5).

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Two-dimensional NMR studies of acrylate copolymers

Pure and Applied Chemistry ◽

10.1351/pac-con-08-06-01 ◽

2009 ◽

Vol 81 (3) ◽

pp. 389-415 ◽

Cited By ~ 10

Author(s):

A. S. Brar ◽

Ashok Kumar Goyal ◽

Sunita Hooda

Keyword(s):

Methyl Methacrylate ◽

Methyl Acrylate ◽

Quantum Coherence ◽

Multiple Bond ◽

Microstructural Analysis ◽

2D Nmr ◽

Correlation Spectroscopy ◽

Nmr Studies ◽

Poly Methyl Methacrylate ◽

Nmr Study

High-resolution NMR spectroscopy is the most versatile, reliable, and generally acceptable technique for the determination of the microstructure of polymers. 2D NMR techniques, along with 1D NMR, have more potential to study absolute configurational assignments and sequence distribution of copolymers. Physical and chemical properties of polymers are influenced fundamentally by their microstructure. We discuss the detailed microstructure analysis of a large number of homopolymers, copolymers, and terpolymers. 2D NMR study of poly(methyl methacrylate) (PMMA), poly(methyl acrylate) (PMA), and poly(methacrylonitrile) (PMAN) is discussed in this article. In addition to homopolymers, 2D heteronuclear single-quantum coherence (HSQC), total correlation spectroscopy (TOCSY), and heteronuclear multiple-bond correlation (HMBC) study of different copolymers such as poly(methyl methacrylate-co-methyl acrylate), poly(styrene-co-methyl methacrylate), and poly(methyl methacrylate-co-methacrylonitrile) have also been reported here. This in turn helps in microstructural analysis of terpolymers such as poly(methacrylonitrile-co-styrene-co-methyl methacrylate), poly(acrylonitrile-co-methyl methacrylate-co-methyl acrylate), and poly(ethylene-co-vinyl acetate-co-carbon monoxide).

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In-vivo NMR studies of deuterium-labeled photosensitizers in mice tumor model

10.1117/12.146327 ◽

1993 ◽

Author(s):

Subbaraya Ramaprasad ◽

Y. H. Liu ◽

R. K. Pandey ◽

Fuu-Yau Shiau ◽

Kevin M. Smith

Keyword(s):

Tumor Model ◽

Nmr Studies ◽

In Vivo Nmr

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2D-NMR Studies on Bis(Amidinohydrazones). I. A Proton-Carbon Heteronuclear Shift Correlation Study on the Enzyme Inhibitors Methylpropylglyoxal Bis(Amidinohydrazone) and Butylmethylglyoxal Bis(Amidinohydrazone)

Spectroscopy Letters ◽

10.1080/00387019008054466 ◽

1990 ◽

Vol 23 (7) ◽

pp. 877-885 ◽

Cited By ~ 5

Author(s):

Hannu Elo

Keyword(s):

Enzyme Inhibitors ◽

2D Nmr ◽

Correlation Study ◽

Nmr Studies

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The6Li,6Li-INADEQUATE Experiment: A New Tool for 1D- and 2D-NMR Studies of Organolithium Compounds

Helvetica Chimica Acta ◽

10.1002/hlca.19920750322 ◽

1992 ◽

Vol 75 (3) ◽

pp. 883-891 ◽

Cited By ~ 21

Author(s):

Oswald Eppers ◽

Thomas Fox ◽

Harald Günther

Keyword(s):

2D Nmr ◽

Nmr Studies ◽

Organolithium Compounds

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Simultaneous detection of cerebral metabolism of different substrates by in vivo 13C isotopomer MRS

Journal of Neuroscience Methods ◽

10.1016/j.jneumeth.2011.02.021 ◽

2011 ◽

Vol 198 (1) ◽

pp. 8-15 ◽

Cited By ~ 7

Author(s):

Yun Xiang ◽

Jun Shen

Keyword(s):

Cerebral Metabolism ◽

Simultaneous Detection

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Cooperative subunit dynamics modulate p97 function

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1815495116 ◽

2018 ◽

Vol 116 (1) ◽

pp. 158-167 ◽

Cited By ~ 14

Author(s):

Rui Huang ◽

Zev A. Ripstein ◽

John L. Rubinstein ◽

Lewis E. Kay

Keyword(s):

Bound State ◽

Nmr Studies ◽

Biologically Relevant ◽

Aaa Atpase ◽

Cellular Processes ◽

Allosteric Communication ◽

Functional Dynamics ◽

Nmr Study ◽

Wide Range

p97 is an essential hexameric AAA+ ATPase involved in a wide range of cellular processes. Mutations in the enzyme are implicated in the etiology of an autosomal dominant neurological disease in which patients are heterozygous with respect to p97 alleles, containing one copy each of WT and disease-causing mutant genes, so that, in vivo, p97 molecules can be heterogeneous in subunit composition. Studies of p97 have, however, focused on homohexameric constructs, where protomers are either entirely WT or contain a disease-causing mutation, showing that for WT p97, the N-terminal domain (NTD) of each subunit can exist in either a down (ADP) or up (ATP) conformation. NMR studies establish that, in the ADP-bound state, the up/down NTD equilibrium shifts progressively toward the up conformation as a function of disease mutant severity. To understand NTD functional dynamics in biologically relevant p97 heterohexamers comprising both WT and disease-causing mutant subunits, we performed a methyl-transverse relaxation optimized spectroscopy (TROSY) NMR study on a series of constructs in which only one of the protomer types is NMR-labeled. Our results show positive cooperativity of NTD up/down equilibria between neighboring protomers, allowing us to define interprotomer pathways that mediate the allosteric communication between subunits. Notably, the perturbed up/down NTD equilibrium in mutant subunits is partially restored by neighboring WT protomers, as is the two-pronged binding of the UBXD1 adaptor that is affected in disease. This work highlights the plasticity of p97 and how subtle perturbations to its free-energy landscape lead to significant changes in NTD conformation and adaptor binding.

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