Fundamental insight into the interaction between a lithium salt and an inorganic filler for ion mobility using a synergic theoretical-experimental approach.

The present paper aims at providing a fundamental insight into the interaction between a lithium salt and an inorganic filler in a perspective of lithium mobility. Through a synergistic approach, coupling experimental results and molecular dynamics simulations, the influence of the surface chemical state of the nanosilica Stöber-type on the dissociation of LiTFSI and its impact on the lithium conduction properties are studied. For this purpose, the surface modification of silica nanoparticles was performed by different methods such as calcination, lithiation and capping with organosilane. The impact of the surface modification on the dissociation of the lithium salt is further investigated by electrochemical impedance spectroscopy after impregnation of the material with a defined amount of lithium salt. The combined experimental and in silico analyses of the results, performed for the first time on such systems, allow a detailed understanding of the interaction between the salt and the support and should prove itself useful for the future design of hybrid polymer electrolytes in new generation batteries.

Synthesis and in vitro activity of novel N-3 acylated TSAO-T compounds against HIV-1 and HCV.

Preparation of a small library of derivatives of the potent HIV-1 Reverse Transcriptase inhibitor TSAO-T bearing mono or di-carbonyl substituents (designed after docking analysis) at position N-3 is reported. A one-pot synthetic methodology has been developed that involves: (i) mono-reaction of TSAO-T with glutaryl dichloride under phase transfer conditions and (ii) in situ acyclic substitution of the remaining chloro atom by oxygen or nitrogen nucleophiles. The method is compatible with the polyfunctionality of the TSAO-T molecule, proceeds with high conversion yields and allows introducing molecular diversity. The anti-HIV-1 and -HCV activity was studied in cell culture. The new N-3 acylated TSAO-T derivatives are active against HIV-1 (nanomolar range). Anti-HCV activity was observed in the micromolar range, that is at compound concentrations that were found cytostatic against human T-lymphocytes.

The synthesis of polyoxygenated, enantiomerically pure cyclopentane derivatives on route to neplanocin A stereoisomers via alkylidenecarbene species prepared from sugar templates.

Our new method for the generation of alkylidenecarbenes, based on the reaction of trimethylsilylazide/Bu(2)SnO with alpha-cyanomesylates, has been applied to the synthesis of enantiomerically pure polyhydroxylated cyclopentane derivatives from conveniently functionalized sugar intermediates prepared from D-mannose. The stereoselectivity of the 1,5 C-H insertion reaction leading to the major trans-isomers (8a,b) has been assigned by (1)H RMN spectroscopic data, and correctly rationalized by a computational analysis at DFT level. Compounds 8a and 8b have been designed as suitable intermediates for the synthesis of neplanocin A enantiomer.

Synthesis, anti-HIV-1 activity, and modeling studies of N-3 Boc TSAO compound.

The synthesis and the biological evaluation of the anti-HIV-1 activity of TSAO-Boc(3)T (8) are described. The computational analysis showed that the N-3 Boc group promotes new interactions in the binding site of the enzyme leading to a good inhibitory activity.

Synthesis and anti-HIV1 biological activity of novel 5''-ATSAO compounds.

Aza TSAO-T derivatives bearing a substituted dihydroisothiazole dioxide ring with a phenyl group at 5'' position were prepared. Biological evaluation showed that phenyl group gives rise to a dramatical decrease of the inhibitory effect.

Computational analysis of aza analogues of [2',5'-bis-O-(tert-butyldimethylsilyl)-beta-D-ribofuranose]-3'-spiro-5"-(4"-amino-1",2"-oxathiole-2",2"-dioxide) (TSAO) as HIV-1 reverse transcriptase inhibitors: relevance of conformational properties on the inhibitory activity.

We have carried out a theoretical analysis of aza analogues of [2',5'-bis-O-(tert-butyldimethylsilyl)-beta-D-ribofuranosyl]-3'-spiro-5"-(4"-amino-1",2"-oxathiole-2",2"-dioxide) by a variety of computational tools, aimed to account for the effect of the endocyclic amino moiety N-2" on the inhibitory activity against HIV-1. Docking studies suggest that compounds substituted at the N-3 and N-2' ' positions present the same binding mode to the [2',5'-bis-O-(tert-butyldimethylsilyl)-beta-D-ribofuranosyl]-3'-spiro-5"-(4"-amino-1",2"-oxathiole-2",2"-dioxide)thymine prototype, where the endocyclic amino group remains mostly exposed to the solvent. A careful conformational analysis performed through different theoretical levels, from molecular mechanics to high-level quantum mechanical calculations, provides a rationalization based on conformational preferences, which appears as strongly determined by the substitution at N-2", and on electrostatic effects from the bulk water.

First synthesis and evaluation of the inhibitory effects of aza analogues of TSAO on HIV-1 replication.

Aza TSAO-T derivatives bearing a dihydroisothiazole dioxide ring instead of an oxathiole dioxide ring at the C-3' position on the sugar moiety were prepared. We have synthesized four families of compounds depending on substitution at both N-3 and N-2' '. Biological evaluation showed that these compounds are HIV-1(III(B))-specific and potent reverse transcriptase inhibitors with EC(50) values between 0.13 and 3.5 microM in cell culture.

Synthesis of AZA analogues of TSAO.

TSAO derivatives which were first synthesized in 1992 have shown strong inhibitory effect and selectivity against HIV-1 (Camarasa, M.J.; Pérez-Pérez, M.J.; San-Félix, A.; Balzarini, J.; De Clercq, E. J. Med. Chem. 1992, 35, 2721-2727). The structure-activity relationship of these derivatives has shown strong binding between the amino acids constituting the reverse transcriptase and the different pharmacophore (tert-butyldimethylsilyl group, amino and sulfonate groups of the TSAO derivatives) (Camarasa, M.J.; San-Félix, A.; Pérez-Pérez, M.J.; Velázquez, S., Alvarez, R.; Chamorro, C.; Jimeno, M.L.; Pérez, C.; Gago, F.; De Clercq, E.; Balzarini, J. J. Carbohydr. Chem. 2000, 19, 6403-6406). We described the synthesis of an original TSAO analogue where, basically, the O-1'' atom is replaced by a nitrogen atom.