Direct deuteration of hinokitiol and its mechanistic study

2021 ◽  
Vol 85 (2) ◽  
pp. 215-222
Author(s):  
Yoshimichi Sakakibara ◽  
Kota Osada ◽  
Yasumitsu Uraki ◽  
Makoto Ubukata ◽  
Kengo Shigetomi
Keyword(s):  
Nmr Spectra ◽  
Biosynthetic Pathway ◽  
Molecular Probe ◽  
Mechanistic Study ◽  
Natural Environments ◽  
2H Nmr ◽  
Deuterium Labeling ◽  
Aliphatic Group ◽  
Bacteria And Fungi ◽  
Moderate Yield

ABSTRACT Hinokitiol has a broad antibacterial activity against bacteria and fungi. While its biosynthetic pathway has been intensively studied, its dynamics in natural environments, such as biodegradation pathway, remain unclear. In this study, the authors report a direct deuterium labeling of hinokitiol as a traceable molecular probe to serve those studies. Hinokitiol was subjected to the H2-Pd/C-D2O conditions and deuterated hinokitiol was obtained with excellent deuteration efficiencies and in moderate yield. The 1H and 2H NMR spectra indicated that all ring- and aliphatic hydrogens except that on C-6 were substituted by deuterium. According to the substrate scope and computational chemistry, deuteration on tropolone ring was suggested to proceed via D+-mediated process, and which was supported by the results of the experiment with trifluoroacetic acid and Pd(TPP)4. On the other hand, the deuteration on aliphatic group was predicted to be catalyzed by Pd(II) species.

scholarly journals Carotenoids in nature: insights from plants and beyond

2011 ◽  
Vol 38 (11) ◽  
pp. 833 ◽  
Author(s):  
Christopher I. Cazzonelli
Keyword(s):  
Biosynthetic Pathway ◽  
Large Family ◽  
New Wave ◽  
Environmental Signals ◽  
Carotenoid Accumulation ◽  
Photosynthetic Organisms ◽  
Essential Components ◽  
Yellow Orange ◽  
Commercially Important ◽  
Bacteria And Fungi

Carotenoids are natural isoprenoid pigments that provide leaves, fruits, vegetables and flowers with distinctive yellow, orange and some reddish colours as well as several aromas in plants. Their bright colours serve as attractants for pollination and seed dispersal. Carotenoids comprise a large family of C40 polyenes and are synthesised by all photosynthetic organisms, aphids, some bacteria and fungi alike. In animals carotenoid derivatives promote health, improve sexual behaviour and are essential for reproduction. As such, carotenoids are commercially important in agriculture, food, health and the cosmetic industries. In plants, carotenoids are essential components required for photosynthesis, photoprotection and the production of carotenoid-derived phytohormones, including ABA and strigolactone. The carotenoid biosynthetic pathway has been extensively studied in a range of organisms providing an almost complete pathway for carotenogenesis. A new wave in carotenoid biology has revealed implications for epigenetic and metabolic feedback control of carotenogenesis. Developmental and environmental signals can regulate carotenoid gene expression thereby affecting carotenoid accumulation. This review highlights mechanisms controlling (1) the first committed step in phytoene biosynthesis, (2) flux through the branch to synthesis of α- and β-carotenes and (3) metabolic feedback signalling within and between the carotenoid, MEP and ABA pathways.

Deuterium Quadrupolar Parameters from 1H and 2H NMR Spectra for Pyridine-d5, Benzonitrile-d5 and Chlorobenzene-d5 Using Liquid Crystal Solvents

1986 ◽  
Vol 41 (1-2) ◽  
pp. 431-435 ◽  
Author(s):  
R. Ambrosetti ◽  
D. Catalano ◽  
C. Forte ◽  
C. A. Veracini
Keyword(s):  
Liquid Crystal ◽  
Nmr Spectra ◽  
Order Parameters ◽  
Dipolar Couplings ◽  
Coupling Constants ◽  
2H Nmr ◽  
H Nmr ◽  
Quadrupolar Coupling ◽  
Asymmetry Parameters ◽  
Quadrupolar Splittings

T he quadrupolar coupling constants (DQCC) and the asymmetry parameters (η) for the ortho, meta and para deuterons in pyridine-d5, benzonitrile-d5 and chlorobenzene-d5 were determined by NMR spectroscopy in oriented phases. The 1H and 2H NMR spectra were recorded in the following solutions in liquid crystal solvents: pyridine + pyridine-d5 in PCH , in ZLI 1167 and in EBBA; benzonitrile + benzonitrile-d5 and chlorobenzene + chlorobenzene-d5 in the same solvents.The order parameters of the non-deuterated solutes in the various solutions were calculated using the dipolar couplings of the proton spectra and the rα structures taken from the literature. The same order parameters were assumed to describe also the orientation of the deuterated solute in the corresponding solutions.Each 2H spectrum yielded three quadrupolar splittings for the three different deuterated positions in the labelled solute. The splittings from the three different solutions of the same solute, together with the order parameters and the rα structure, were used to determine DQCC and η of the ortho, meta and para deuterons (Pyridine-d5: DQCCortho= 183(1) kHz, ηortho = 0.030(5), DQCCmeta = 185(1) kHz, ηmeta = 0.030(10), DQCCpara = 188(6) kHz, ηpara = 0.01(5). Benzonitrile-d5: DQCCortho = 171(12) kHz, ηortho = 0.07(3), DQCCmeta = 175(12) kHz, ηmeta = 0.05(3), DQCCpara = 176(4) kHz, ηpara = 0.10(7). Chlorobenzene-d5: DQCCortho = 180(2) kHz, ηortho = 0.06(1), DQCCmeta = 174(2) kHz, ηmeta = 0.09(3), DQCCpara= 182(4) kHz, ηPara = 0.06(4)). The results are discussed, as well as the limits and possibilities of the method used.

Multiaxial Reorientationsof ND+4 Ions Studied by 2H-NMR Spectroscopy

1991 ◽  
Vol 46 (10) ◽  
pp. 829-840 ◽  
Author(s):  
Z. T. Lalowicz ◽  
S. F. Sagnowski
Keyword(s):  
Nmr Spectroscopy ◽  
Density Matrix ◽  
Nmr Spectra ◽  
Activation Energies ◽  
Matrix Formalism ◽  
2H Nmr ◽  
Jump Frequency ◽  
H Nmr ◽  
2H Nmr Spectroscopy ◽  
Density Matrix Formalism

AbstractThe density matrix formalism is used to simulate motional averaging in the 2H-NMR spectra of reorienting ND+4 ions. The development of the spectra under increasing jump frequency about a single C3 or C2 axis is followed. Next we assume a hierarchy of axes in terms of activation energies sufficient to reach extreme narrowing conditions for some axes before activating jumps about a next one. Primary reorientations about the fastest C3 or C2 symmetry axes define the shape of spectra, the width of which is then stepwise reduced by fast reorientations about the subsequent axes in a postulated sequence of statistically uncorrelated jumps.

2H NMR spectra of trimethylsilyl groups anchored on a silica surface

1986 ◽  
Vol 173 (2-3) ◽  
pp. L655-L658
Author(s):  
B. Boddenberg ◽  
R. Grosse ◽  
U. Breuninger
Keyword(s):  
Nmr Spectra ◽  
Silica Surface ◽  
2H Nmr ◽  
Trimethylsilyl Groups

Inhibition of Diamino Pelargonic Acid Aminotransferase, an Enzyme of the Biotin Biosynthetic Pathway, by Amiclenomycin: A Mechanistic Study

2003 ◽  
Vol 86 (11) ◽  
pp. 3836-3850 ◽  
Author(s):  
Stéphane Mann ◽  
Dominique Florentin ◽  
Denis Lesage ◽  
Thierry Drujon ◽  
Olivier Ploux ◽  
...  
Keyword(s):  
Biosynthetic Pathway ◽  
Pelargonic Acid ◽  
Mechanistic Study

Angular dependence of 1H- and 2H-NMR spectra of H2O and D2O absorbed in cellulose acetate film

1987 ◽  
Vol 25 (10) ◽  
pp. 2149-2163 ◽  
Author(s):  
Kazunori Matsumura ◽  
Kikuko Hayamizu ◽  
Takashi Nakane ◽  
Hiroshi Yanagishita ◽  
Osamu Yamamoto
Keyword(s):  
Cellulose Acetate ◽  
Angular Dependence ◽  
Nmr Spectra ◽  
2H Nmr ◽  
Cellulose Acetate Film

scholarly journals Synthesis and biological evaluation of new Benzimidazole derivatives

2018 ◽  
Vol 29 (1) ◽  
pp. 107 ◽  
Author(s):  
Hadeel Majed ◽  
Firyal W. Askar
Keyword(s):  
Schiff Bases ◽  
Nmr Spectra ◽  
Antimicrobial Activities ◽  
Biological Evaluation ◽  
Benzimidazole Derivatives ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
H Nmr ◽  
Bacteria And Fungi ◽  
Synthesis And Biological Evaluation

Agroup of benzimidazole derivatives bearing different heterocyclic moieties such as Schiff bases, 2-azetidinone and  4-thiazolidinone were efficiently prepared. The structures of the newly compounds were characterized by FTIRand ¹H NMR spectra. The synthesized compounds were evaluated for their antimicrobial activities against gram-positive and gram negative bacteria and fungi using the microdilution procedure.

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