32445-39-9Relevant articles and documents
Metal complexation of a D -ribose-based ligand decoded by experimental and theoretical studies
Cisnetti, Federico,Marechal, Jean-Didier,Nicaise, Magali,Guillot, Regis,Desmadril, Michel,Lambert, Francois,Policar, Clotilde
, p. 3308 - 3319 (2012/10/18)
A combination of experimental and theoretical methods have been used to elucidate the complexation properties of a new sugar-derived hexadentate ligand, namely methyl 2,3,4-tri-O-(2-picolyl)-β-D-ribopyranoside (L). The coordination bond lengths in the complexes with MnII, Co II, NiII, and ZnII show substantial deviations from ideal octahedra with deformation towards trigonal-prismatic geometries, which is indicative of a conformationally constrained ligand. The metal-cation-ligand interactions were studied for L and the acyclic analogue L' [1,2,3-tri-O-(2-picolyl)-1,2,3-propanetriol] by spectroscopic methods and isothermal calorimetric titrations for the series MnII, Co II, NiII, ZnII, and CuII. The results indicate a stabilization of the complexes obtained with L compared with L', depending on the nature of the metal. Molecular modeling studies showed that the presence of the sugar moiety strongly favors conformations compatible with metal binding, which suggests an entropic origin of the stabilization of L complexes with regards to L' complexes. Moreover, the differences in the metal chelation profiles of L and L' are related to the constraints in the sugar group in the metal-bound structures. This study shows that foreseeing the degree of preorganization of flexible ligands may drive the design of a new generation of chelating compounds. A new sugar-derived ligand, with its coordination site embedded in a pyranoside cycle in the chair conformation, has been designed. Its transition-metal complexes were characterized by experimental and complexation methods and revealed a dramatic impact of the preorganization and complementarity of the carbohydrate scaffold on the metal binding.
Vesparioside from the marine sponge Spheciospongia vesparia, the first diglycosylceramide with a pentose sugar residue
Costantino, Valeria,Fattorusso, Ernesto,Imperatore, Concetta,Mangoni, Alfonso
, p. 368 - 373 (2007/10/03)
The marine sponge Spheciospongia vesparia produces vesparioside (1a), a diglycosylated glycosphingolipid which is the first example of a natural diglycosylceramide with a pentose sugar residue. The structure of vesparioside was mostly determined by extensive spectroscopic analysis but determination of the nature of the alkyl chains and elucidation of the absolute stereochemistry of the sugars and of the ceramide required chemical degradation. In this respect, an improved and simplified procedure for the microscale chemical degradation of glycosphingolipids was employed here for the first time. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.
