1H NMR study of the interaction of trans-resveratrol with soybean phosphatidylcholine liposomes

Resveratrol (RSV) is a well-known natural derivative with a wide range of biological and pharmacological activities. Despite of these demonstrated properties, it exhibits low both aqueous solubility and chemical stability and therefore low bioavailability. Consequently, the major concern of the technological research is to exploit delivery systems able to overcome bioavailability problems. In the recent past liposomes have been successfully studied for these purposes. In this paper, 1H-NMR spectroscopy, Nuclear Overhauser Spectroscopy (NOESY) as well as Paramagnetic Relaxation Enhancements (PRE) experiments have been carried out to quantitatively investigate the incorporation of resveratrol, at both the liposome preparation stage and by preformed liposomes, also with the aim to characterize resveratrol- soybean phosphatidylcholine (P90G) lipid bilayer interactions. Overall results of 1H NMR spectroscopy analysis suggest that RSV is located nearby the phosphocholine headgroups and also provide quantitative data on the incorporation of RSV (5% w/w), which corresponds to a 150-fold increase with respect to the solubility of RSV in water. Beside, considering that the same level of RSV incorporation was obtained via spontaneous uptake by preformed P90G liposomes, it can be concluded that RSV easily diffuses through the lipid bilayer

Intermolecular Dipole-Dipole Spin Relaxation of Xenon-129 Dissolved in Benzene. A Molecular-Dynamics Simulation Study

By use of molecular-dynamics simulations for xenon dissolved in liquid benzene, it is confirmed that the intermolecular dipole-dipole spin-relaxation mechanism contributes significantly to the relaxation of 129Xe. The calculated dipolar relaxation time (750 ± 160 s) lies in the range of the experimental determinations, which are 390 and 870 s. The time correlation function of the Xe-H spin dipole-dipole interaction displays a fast decay between 0 and 5 ps, decreases exponentially between 5 and 15 ps, and follows a t^(−3/2) power law at longer times. The Xe-H correlation function can be, in very good approximation, factored into distance and angular contributions; the latter is found to be the major contribution. The influence of the rotational dynamics of the solvent molecules is investigated on the basis of comparisons between the Xe-H time correlation functions and the corresponding functions for spins located at the center of mass of the benzene molecules. Finally, the relaxation of 129Xe and 131Xe are compared. It is shown that the quadrupole relaxation of 131Xe depends essentially on the rotational motions of the solvent molecules while the dipolar relaxation of 129Xe is largely dependent on the translational motions.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

NMR Study of the Reversible Trapping of SF6 by Cucurbit[6]uril in Aqueous Solution

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Amoroso-Robinson relation and Dorfman-Steiner theorem A multivariable extension

SIGLETIB: RN 9560 (148) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

A continuous time, deterministic, nonstationary model of economic ordering

For presentation at the 6. European Congress on Operations Research, Vienna, 19-22 Jul 1983SIGLETIB: RN 9560 (124) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Activités anti-radicalaires de trois anthocyanines monoglucosides isolées des graines de Glycine max

Des graines du soja noir, Glycine max, cultivé au Burkina Faso, trois anthocyanes monoglucosides ont été isolées et caractérisées à l'aide de méthodes chimiques, chromatographiques (CCM, CLHP et CP), spectrométriques (UV-Vis. SM et RMN). Ainsi les graines de Glycine max renferment majoritairement la delphinidine 3-O-β-D-glucopyranoside, la cyanidine 3-O-β-D-glucopyranoside et la pétunidine 3-O-β-D-glucopyranoside. La méthode au DPPH nous a permis de déterminer les activités antioxydantes de chacun des trois anthocyanes de Glycine max. Les résultats ont été comparés à ceux du thé (thé Lipton) et du vin rouge trouvés dans le commerce local. Il ressort de cette étude la classification suivante selon un ordre croissant du pouvoir antioxydant: Extraits totaux du nin rouge < Extraits totaux de Glycine max < cyanidine 3-O-β-D-glucopyranoside < delphinidine 3-O-β-D-glucopyranoside < pétunidine 3-O-β-D-glucopyranoside < Thé Lipton.info:eu-repo/semantics/publishe