Search results for "molecular interactions"
showing 10 items of 51 documents
Unprecedented multi-stable spin crossover molecular material with two thermal memory channels.
2013
et al.
On the nature of interactions in the F2 OXe(…) NCCH3 complex: Is there the Xe(IV)N bond?
2016
Nature of the bonding in isolated XeOF2 molecule and F2 OXe(…) NCCH3 complexes have been studied in the gas phase (0 K) using Quantum Chemical Topology methods. The wave functions have been approximated at the MP2 and DFT levels of calculations, using the APFD, B3LYP, M062X, and B2PLYP functionals with the GD3 dispersion correction. The nature of the formal XeO bond in the XeOF2 monomer depends on the basis set used (all-electron vs. the ecp-28 approximation for Xe). Within the all-electron basis set approach the bond is represented by two bonding attractors, Vi = 1,2 (Xe,O), with total population of about 1.06e and highly delocalized electron density in both bonding basins. No bonding bas…
Truncated internalin A and asymptomatic Listeria monocytogenes carriage: in vivo investigation by allelic exchange
2004
ABSTRACT Allelic exchange of the region coding for the C terminus of InlA between one epidemic (with an 80-kDa InlA) and one asymptomatic (with a 47-kDa InlA) carriage Listeria monocytogenes strain confirmed the need for this region for internalin entry in vitro. Interestingly, restoration of internalin A functionality did not result in full virulence in chicken embryo assays.
Efficiency of antidepressant drugs as monoamine reuptake inhibitors: analysis of the hydrophobicity influence using biopartitioning micellar chromato…
2004
The reuptake blockade of biogenic amines by antidepressants is related not only to their therapeutics effects, but also to their side effects and potential drug-drug interactions. As an alternative to classical quantitative structure-activity relationships studies, in this work we propose different quantitative retention-activity relationships (QRAR) models that are able to describe the monoamine reuptake inhibition by antidepressants. The retention of compounds is measured using a biopartitioning micellar chromatography (BMC) system that can simulate the same hydrophobic, electronic and steric molecular interactions as those that condition drug activity. Since all the compounds considered …
Iontophoresis: electrorepulsion and electroosmosis.
2000
Over the last 10-15 years, the electrical enhancement of drug delivery across the skin has undergone intense investigation. During this period, considerable amounts of experimental data have been generated, and the successful enhancement of a diverse array of molecules has been achieved. Indeed, the commercial exploitation of the method can be envisaged within the next few years. Despite this progress, however, the mechanistic understanding of iontophoresis remains a challenging scientific question that is yet to be fully resolved. The routes of permeation under the influence of an applied electrical potential, and the molecular interactions of the transporting drug with these pathways, hav…
Experimental and theoretical NMR studies of interaction between phenylalanine derivative and egg yolk lecithin
2014
The interaction of phenylalanine diamide (Ac-Phe-NHMe) with egg yolk lecithin (EYL) in chloroform was studied by 1H and 13C NMR. Six complexes EYL–Ac-Phe-NHMe, stabilized by N–H···O or/and C–H···O hydrogen bonds, were optimized at M06-2X/6-31G(d,p) level. The assignment of EYL and Ac-Phe-NHMe NMR signals was supported using GIAO (gauge including atomic orbital) NMR calculations at VSXC and B3LYP level of theory combined with STO-3Gmag basis set. Results of our study indicate that the interaction of peptides with lecithin occurs mainly in the polar ‘head’ of the lecithin. Additionally, the most probable lecithin site of H-bond interaction with Ac-Phe-NHMe is the negatively charged oxygen in …
Dissection of Genetic Cell Programmes Driving Early Arbuscular Mycorrhiza Interactions
2008
The persistence through evolution of the arbuscular mycorrhiza (AM) symbiosis between Glomeromycota and plants is probably due to a widespread molecular dialogue between the two partners. Most studies have focussed on established mycorrhizal systems whilst evidence for cellular commitment of the symbiotic partners during early developmental phases is recent. Whereas spore germination by AM fungi can occur spontaneously, subsequent hyphal branching, appressoria differentiation, root penetration and intraradical development leading to symbiosis establishment are under the control of molecular interactions between the two partners. In this chapter, recent work on AM fungus–plant interactions i…
Magnetic Molecular Conductors Based on Bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) and the Tris(chlorocyananilato)ferrate(III) Complex
2019
Electrocrystallization of the bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) organic donor in the presence of the [Fe(ClCNAn)3]3– tris(chlorocyananilato)ferrate(III) paramagnetic anion in different stoichiometric ratios and solvent mixtures afforded two different hybrid systems formulated as [BEDT-TTF]4[Fe(ClCNAn)3]·3H2O (1) and [BEDT-TTF]5[Fe(ClCNAn)3]2·2CH3CN (2) (An = anilato). Compounds 1 and 2 present unusual structures without the typical segregated organic and inorganic layers, where layers of 1 are formed by Λ and Δ enantiomers of the anionic paramagnetic complex together with mixed-valence BEDT-TTF tetramers, while layers of 2 are formed by Λ and Δ enantiomers of the paramagnetic…
Dissecting the packing forces in mixed perfluorocarbon/aromatic co-crystals
2021
We carried out a systematic evaluation of the packing forces in co-crystals featuring monoiodo- and diiodo-perfluoroalkanes and 1,2,4-oxadiazoles through single crystal X-ray diffraction and theoretical analysis. The molecules assemble via a combination of halogen bonding and specific dispersive interactions involving the perfluorinated units. We quantitatively elucidated the nature and strength of such interactions through solid-state calculations and Hirshfeld surface analysis. One of the co-crystals, formed by two monoiodoperfluorodecane molecules, the longest perfluorinated chain ever solved at the atomic level, allowed us to fully highlight the role of fluorous interactions.