ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Relaxation times  (2)
  • 1,2-bis(palmitoyloxy)-3-propyl 2-trimethylarsonioethylphosphonate  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Synthesis and characterization of rac-1,2-bis(palmitoyloxy)-3-propyl (2-trimethylarsonioethyl)phosphonate, an arsenic-containing phosphonolipid (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 4 (1990), S. 103-109 
    Details
    ISSN: 0268-2605
    Keywords: Arsenic-containing lipids ; 2-trimethylarsonioethylphosphonic acid bromide ; 1,2-bis(palmitoyloxy)-3-propyl 2-trimethylarsonioethylphosphonate ; arsenic-containing phosphonolipid ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Arsenic analogs of lecithins (i.e. with replacement of nitrogen by arsenic in the choline group) are probably trace constituents of phospholipids in many organisms. Attempts to synthesize 1,2-bis(palmitoyloxy)-3-propyl 2-trimethylarsonioethyl phosphate (arsenolecithin) according to wellestablished procedures for the synthesis of the corresponding nitrogen compound failed. However, 1,2-bis(palmitoyloxy)-3-propyl 2-trimethylarsonioethylphosphonate, an arsenic-containing phosphonolipid, was obtained in 16% yield by reacting 1,2-bis(palmitoyloxy)-3-iodopropane with silver 2-trimethylarsonioethylphosphonate in isopropanol. The precursors to the arsenic-containing phosphonolipid were obtained by quaternization of trimethylarsine with diethyl 2-bromoethylphosphonate, hydrolysis of the resulting product with concentrated hydrochloric acid, and reaction of the phosphonic acid with silver oxide to give silver 2-trimethylarsonioethylphosphonate. Quaternization and hydrolysis proceeded almost quantitatively. The silver phosphonate was not isolated but was used in situ.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aoc.590040204
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    1H and 13C NMR spectra, 13C NMR relaxation times and molecular modelling studies of the narcotic agonist-antagonist α-( - )-N-propynylnormetazocine (1992)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 30 (1992), S. 20-29 
    Details
    ISSN: 0749-1581
    Keywords: N-Propynylnormetazocine ; Conformation ; Relaxation times ; Motional analysis ; Molecular Modelling ; 1H and 13NMR spectra ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The analysis of high-frequency 1H and 13C NMR spectra and both 1H—1H homonuclear and 1H—13C heteronuclear chemical shift correlation experiments indicate that N-propynlnormetazocine (NPMH+) is configurationally heterogeneous in solution, with the N-equatorial isomer being more populated than the N-axial isomer. The experimental proton-proton coupling constants measured for both diastereoisomers were in agreement with the calculated values for a chair conformation of the piperidine ring. AM1 and MM2 theoretical calculations both indicated the chair conformation as that preferred by the piperidine ring, and the N-equatorial isomer as being energetically favoured with respect to the N-axial form. The best fit of the 13C T1 relaxation time data and the related motional analysis of NPMH+ was carried out using the anisotropic model of reorientation with superimposed internal motion. The results showed an increase of the rotational anisotropy of the molecule on passing from the gas phase to the solution state.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1260300106
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Reorientational dynamics and internal mobility of the mixed agonist-antagonist opioid narcotic cyclazocine by 13C NMR relaxation times (1993)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 31 (1993), S. 823-828 
    Details
    ISSN: 0749-1581
    Keywords: Cyclazocine ; 13CNMR ; Relaxation times ; Reorientational dynamics ; Internal mobility ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The motional behaviour of the mixed agonist-antagonist opioid narcotic cyclazocine (2-cyclopropylmethyl-2′-hydroxy-5,9-dimethyl-6,7-benzomorphan) as a cationic species (CLZH +) was analysed by 13C NMR spin-lattice relaxation times (T1). Both AM1 and MM2 theoretical calculations were performed to predict the preferred conformations and torsional energetics of CLZH+ in the vapour phase. The analysis of the experimental T1 data (in aqueous solution) was performed by using an analytical model to describe the overall and internal motions of the molecule. The best fit of the relaxation times allowed the detection, in the liquid phase, of effective solute-solvent interactions and the fully anisotropic diffusive process of the molecule. The motional parameters obtained indicated an increased retational anisotropy of CLZH+ on passing from the gas phase to the solution state. Different activation energies arising from separate solvation effects were found for the motion of the 10-Me and 11-Me groups. The fitted energies and transition energies matrix relative to the internal motion of the N-cyclopropylmethyl group indicated that the preferred conformational states are not isolated and that the overall and internal motions are of the same order of magnitude.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1260310906
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...