STUDIES ON STRUCTURE AND SYNTHESIS OF ARTEANNUIN AND RELATED COMPOUNDS Ⅷ. DETERMINATION OF CONFIGURATION OF ARTEANNUIN DEGRADATION PRODUCTS AND RELATED COMPOUNDS BY ~1H NMR SPECTROSCOPY
On the basis of total acid hydrolysis, methylation analysis, periodate oxidation and NMR studies (1H and 13C) the structure of the repeating unit of the polysaccharide was assigned and indicated only α-(1→4) linked Glucan.
The stereo-structures of Roridin P and Isororidin P were established on the basis of one- and two-dimensional nuclear magnetic resonance (NMR) spectral analyses.
The aim of this study was to synthesize and identify 2,4-dihalogenofluorobenzene (or trihalogenobenzene) derivatives by spectroscopic means, 1H-NMR and 19F-NMR.
The synthesized compounds have been characterized on the basis of elemental analyses, infrared spectroscopy (IR), and nuclear magnetic resonance (NMR).
Two compounds were designed, synthesized, and characterized by 1H-nuclear magnetic resonance (1H-NMR), ultraviolet (UV)-visible, and matrix-assisted laser desorption/ionization (MALDI) mass spectra.
The stereo-structures of Roridin P and Isororidin P were established on the basis of one- and two-dimensional nuclear magnetic resonance (NMR) spectral analyses.
The synthesized compounds have been characterized on the basis of elemental analyses, infrared spectroscopy (IR), and nuclear magnetic resonance (NMR).
Two compounds were designed, synthesized, and characterized by 1H-nuclear magnetic resonance (1H-NMR), ultraviolet (UV)-visible, and matrix-assisted laser desorption/ionization (MALDI) mass spectra.
Both monomers and polymers were characterized by Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance, and elemental analysis measurements, and their structures were identified.
Derivatives of MEC were found by 1H-NMR spectroscopy under stress conditions in colorless mutants of the bacteria and isolated to be subsequently purified and used for modulation of the immune system of animals.
Chemical analysis and 13C-NMR spectroscopy revealed the presence of D-mannopyranose and D-glucopyranose in the heteropolysaccharide at a molar ratio of 1.39 : 1.
Each NMR spectra was data-processed to provide 238 intensity-related descriptors as input coordinates in a multidimensional space and analyzed by PR method.
13C NMR spectra of both fractions were identical with respect to the number and positions of signals, which indicates that their primary structures were identical.