scholarly journals Phytochemical Investigation of the Australian Lichens Ramalina glaucescens and Xanthoria parietina

2009 ◽  
Vol 4 (7) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
Daniel A. Dias ◽  
Sylvia Urban
Keyword(s):  
Antibacterial Properties ◽  
Usnic Acid ◽  
2D Nmr ◽  
Antibacterial Activities ◽  
2D Nmr Spectroscopy ◽  
Full Characterization ◽  
Phytochemical Investigation ◽  
Xanthoria Parietina ◽  
Shift Assignment

Phytochemical investigation of the Australian lichen, Ramalina glaucescens resulted in the isolation of a new halogenated depside, 5-chlorosekikaic acid 5, together with (+)-usnic acid 1, sekikaic acid 2, atranorin 6 and parietin 7, the latter of which was isolated from the associated (co-occurring) lichen, X. parietina. Compound 5 is suspected to be an artifact of the isolation procedure. All structures were assigned using spectroscopic methods and mass spectrometry. In addition to the full characterization of 5, this report represents the first application of 2D NMR spectroscopy to complete the unequivocal chemical shift assignment for compounds 2 and 7. Compounds 1-2 and 5-7 all displayed varying degrees of antitumor activity (ranging from an IC50 of 15 μM to >44 μM) with compounds 1, 2 and 5 also displaying antibacterial properties. Of these, (+)-usnic acid 1 displayed the most significant antitumor and antibacterial activities.

Introduction of Phosphine-Gold(I) Precursors into a Cys-modified Enkephalin Neuropeptide as Part of Solid Phase Peptide Synthesis

2007 ◽  
Vol 62 (3) ◽  
pp. 460-466 ◽  
Author(s):  
Judy Caddy ◽  
Ulrich Hoffmanns ◽  
Nils Metzler-Nolte
Keyword(s):  
Nmr Spectra ◽  
Solid Phase ◽  
Solid Phase Peptide Synthesis ◽  
2D Nmr ◽  
Protecting Group ◽  
2D Nmr Spectroscopy ◽  
Full Characterization ◽  
Gold Thiolate ◽  
Optimized Conditions

The synthesis and full characterization of a series of (triphenylphosphine)gold complexes with thiol-containing amino acids and peptides is reported. Boc-Cys-Au(PPh3) was prepared in solution by reaction of Boc-Cys-OH with (Ph3P)AuCl. The related Ac-Cys-Au(PPh3) and an Au derivative of the cysteine-modified neuropeptide enkephalin (Enk), [Cys]5-Au(PPh3)-Enk, were prepared on the resin, using the orthogonal trityl-protecting group on Cys. For comparison, the metal-free [Cys]5-Enk and an S-tert-butyl-protected [Cys]5-Enk were also prepared. Most noteworthy, gold complexation works best when carried out on the resin, and the gold thiolate survives cleavage from the resin under optimized conditions. The new conjugates were comprehensively characterized, including 1D and 2D NMR spectroscopy, and mass spectrometry. Along with characteristic changes in the 1H and 13C NMR spectra, 31P NMR spectra reveal a characteristic downfield shift of ca. 5 ppm upon complexation of the Au(PPh3)-fragment to Cys, which is also pertinent in the Au-labelled [Cys]5-Enk.

Design, synthesis and characterization of copper-based coordination compounds with bidentate (N,N and N,O) ligands: reversible uptake of iodine, dye adsorption and assessment of their antibacterial properties

CrystEngComm ◽  
2019 ◽  
Vol 21 (2) ◽  
pp. 251-262 ◽  
Author(s):  
Azizolla Beheshti ◽  
Elham Sadat Mousavi Fard ◽  
Maciej Kubicki ◽  
Peter Mayer ◽  
Carmel T. Abrahams ◽  
...  
Keyword(s):  
Coordination Compounds ◽  
Copper Complexes ◽  
Antibacterial Properties ◽  
Dye Adsorption ◽  
Antibacterial Activities ◽  
Synthesis And Characterization ◽  
Design Synthesis ◽  
Iodine Adsorption

This work presents the synthesis of close-packed copper complexes with an uncommon ability for dye and iodine adsorption and antibacterial activities.

Synthesis of a Mycobacterium tuberculosis Tetra-acylated Sulfolipid Analogue and Characterization of the Chiral Acyl Chains Using Anisotropic NAD 2D-NMR Spectroscopy

2013 ◽  
Vol 78 (15) ◽  
pp. 7648-7657 ◽  
Author(s):  
Aurélie Lemétais ◽  
Yann Bourdreux ◽  
Philippe Lesot ◽  
Jonathan Farjon ◽  
Jean-Marie Beau
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Nmr Spectroscopy ◽  
2D Nmr ◽  
2D Nmr Spectroscopy ◽  
Acyl Chains

scholarly journals Synthesis and characterization of allyl- and vinyl-substituted 1,2-bis(tetrazolo)ethanes as polymeric precursors

2016 ◽  
Vol 71 (12) ◽  
pp. 1199-1209
Author(s):  
Vera A. Hartdegen ◽  
Maximilian S. Hofmayer ◽  
Konstantin Karaghiosoff ◽  
Thomas M. Klapötke
Keyword(s):  
Allyl Bromide ◽  
2D Nmr ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
2D Nmr Spectroscopy ◽  
X Ray ◽  
Physical Stimuli ◽  
Thermal Stability Of

AbstractOn the basis of 1,2-bis(5-tetrazolo)ethane (BTE) the corresponding twofold vinyl and allyl N-substituted derivatives were synthesized using 1,2-dibromoethane and allyl bromide, respectively. The compounds were obtained as two different constitutional isomers. Both species were analyzed using NMR and IR spectroscopy, elemental analysis, as well as mass spectrometry. In the case of the diallyl bistetrazoles, the two isomers were characterized using 2D NMR spectroscopy. The synthesis of the divinyl compounds gave crystals of the 2,2′-N-substituted isomer, which were analyzed by single-crystal X-ray diffraction. The thermal stability of the compounds was determined using differential scanning calorimetry (DSC) and gave decomposition temperatures around 190°C and 230°C. For the investigation of the inherent energetic potential, sensitivities toward physical stimuli and detonation parameters were determined. The compounds turned out to be insensitive toward friction and impact and possess moderate energetic properties.

scholarly journals Characterization of the Structure of 2-(4-methyl-2 Phenyl-4, 5-dihydrooxazol-4-ylmethyl)-isoindole-1, 3-dione by 1D, COSY and HSQC 2D NMR Spectroscopy

2021 ◽  
pp. 30-37
Author(s):  
Khadim Dioukhane ◽  
Younas Aouine ◽  
Asmae Nakkabi ◽  
Salaheddine Boukhssas ◽  
Hassane Faraj ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
2D Nmr ◽  
The Other ◽  
Two Dimensional ◽  
Hsqc Spectrum ◽  
2D Nmr Spectroscopy ◽  
Perfect Correlation ◽  
Dione Derivative ◽  
The One

The identity of the 2-(4-Methyl-2-phenyl-4,5-dihydrooxazol-4-ylmethyl)-isoindole-1,3-dione, previously synthesized in our laboratory, was proven without doubt by means of 1D and 2D NMR spectroscopy. Two-dimensional NMR spectroscopy played a major role. The analysis of the 2D-COSY spectrum of isoindoline-1,3-dione derivative shows a perfect correlation between neighboring protons. Thus, a correlation was noted between the protons of the phthalimide, H(8) and H(9) on the one hand and H(8') and H(9') on the other hand. The analysis of the 2D-HSQC spectrum of the studied compound indicates a faultless correlation between protons and adjacent carbons, and no correlation in the case of all quaternary carbons.

scholarly journals Bioactive Clerodane Diterpenes from Roots of Carex Distachya

2010 ◽  
Vol 5 (10) ◽  
pp. 1934578X1000501
Author(s):  
Antonio Fiorentino ◽  
Brigida D'Abrosca ◽  
Severina Pacifico ◽  
Angelina Izzo ◽  
Grazia D'Angelo ◽  
...  
Keyword(s):  
Mediterranean Basin ◽  
Chemical Characterization ◽  
Shoot Elongation ◽  
2D Nmr ◽  
Herbaceous Species ◽  
2D Nmr Spectroscopy ◽  
Perennial Plant ◽  
Clerodane Diterpenes ◽  
The Mediterranean Basin

Two new clerodane diterpenes were isolated from roots of Carex distachya Desf., a perennial plant widely distributed in the coastal area of the Mediterranean basin. Chemical characterization of the metabolites was carried out mainly by 1D and 2D NMR spectroscopy. The isolated compounds influenced either positively or negatively the plant growth (root and shoot elongation) of three coexisting herbaceous species.

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