Reynaud C.,CNRS Chemistry Laboratory |
Giorgi M.,Spectropole |
Doucet H.,CNRS Chemistry Institute of Rennes |
Santelli M.,CNRS Chemistry Laboratory
The Diels-Alder reaction of spirobicyclic cyclopentadiene derivatives, prepared by reaction of cyclopentadienyllithium and epichlorohydrin, with maleic anhydride gave a simple access to spiro tricyclic polyoxygenated compounds of synthetic interest. The solvolytic behavior of 1-(tosyloxymethyl)spiro[2.4] hepta-4,6-diene, a 5-spirocyclopentadiene, shows that the ionization of the tosylate was unlikely. © 2010 Georg Thieme Verlag Stuttgart New York. Source
Campolo D.,Aix - Marseille University |
Arif T.,Aix - Marseille University |
Borie C.,Aix - Marseille University |
Mouysset D.,Aix - Marseille University |
And 4 more authors.
Angewandte Chemie - International Edition
An original synthesis of chiral benzofulvenes triggered by organocopper reagents is reported. These enantiopure products are available through a highly chemo-, regio-, diastereo-, and enantioselective bis(alkylating) cycloisomerization process. A double chirality transfer (central-to-axial-to- central) is observed. Double duty: An original synthesis of chiral benzofulvenes was developed through the highly chemo-, regio-, diastereo-, and enantioselective double transfer of alkyl groups to electrophilic enediynes. This organocopper-triggered cycloisomerization proceeds with double transfer of chirality (central-to-axial-to-central). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source
Liu X.,Aix - Marseille University |
Liu X.,Wuhan University |
Wang Y.,Aix - Marseille University |
Wang Y.,Wuhan University |
And 10 more authors.
A 2-oxoglutaric acid (2-OG) probe bearing a methylene group introduced at the C4 position and a vinyl group to replace the carbonyl group at the C2 position elicited characteristic affinity for NtcA, the 2-OG receptor, while maintaining the signaling function of the parent natural metabolite 2-OG. This discovery opens new perspectives in the design, synthesis, and implementation of specific 2-OG analogues as molecular probes for investigating the complex 2-OG signaling pathways. © 2013 American Chemical Society. Source
Liu X.,Wuhan University |
Liu X.,CNRS Interdisciplinary Nanoscience Centre of Marseille |
Chen H.,Wuhan University |
Laurini E.,University of Trieste |
And 9 more authors.
2-Difluoromethylene-4-methylenepentanoic acid (DFMPA), a seemingly deviated analog of 2-oxoglutaric acid (2-OG), could surprisingly mimic its signaling function in cyanobacteria. Computer modeling revealed the favorable binding of DFMPA toward the 2-OG receptor, NtcA, via mutual conformational changes, suggesting that structural alteration of 2-OG is tolerated for it to exercise its signaling role. This extremely useful finding could be exploited for the design of affinity probes with which to study new 2-OG receptors in related signaling pathways. © 2011 American Chemical Society. Source
Laurencon L.,University of Nice Sophia Antipolis |
Sarrazin E.,University of Nice Sophia Antipolis |
Chevalier M.,University of Nice Sophia Antipolis |
Precheur I.,University of Nice Sophia Antipolis |
And 3 more authors.
As part of research for treatments to combat oral dryness, our evaluation of the activity of an aqueous extract of Solidago virgaurea (L.) ssp. alpestris (Asteraceae) revealed activity against Candida albicans hyphae, the pathogenic form of this yeast. Systematic bioassay-guided fractionation of this extract gave an active saponin-containing fraction from which six oleanane-type triterpenoid saponins were isolated. Three of these were isolated for the first time, as 3-O-(β-d-glucopyranosyl-(1 → 3)-β-d-glucopyranosyl)-28- O-(β-d-fucopyranosyl-(1 → 2)-α-l-rhamnopyranosyl-(1 → 3)-β-d-xylopyranosyl-(1 → 4)-α-l-rhamnopyranosyl-(1 → 2)-β-d-xylopyranosyl)-polygalacic acid (virgaureasaponin 4), 3-O-(β-d-glucopyranosyl)-28-O-(β-d-fucopyranosyl-(1 → 2)-α-l-rhamnopyranosyl-(1 → 3)-β-d-xylopyranosyl-(1 → 4)-α-l-rhamnopyranosyl-(1 → 2)-β-d-xylopyranosyl)-polygalacic acid (virgaureasaponin 5) and 3-O-(β-d-glucopyranosyl)-28-O-(α-l- rhamnopyranosyl-(1 → 3)-β-d-xylopyranosyl-(1 → 4)-α-l-rhamnopyranosyl-(1 → 2)-[5-O-acetylapiofuranosyl-(1 → 3)-[4-O-(3-(3-hydroxy-1-oxobutoxy)-1-oxobutyl)]-β-d-fucopyranosyl] -polygalacic acid (virgaureasaponin 6). Their structures were established by carrying out 1D and 2D NMR experiments along with HRMS analyses. All of the six saponins were evaluated to ascertain their inhibition of C. albicans yeast-hyphal conversion, and four of them showed significant inhibition. © 2012 Elsevier Ltd. All rights reserved. Source