6638-76-2Relevant 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
scheme or table, 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.
Novel D-xylose derivatives stimulate muscle glucose uptake by activating AMP-activated protein kinase α
Gruzman, Arie,Shamni, Ofer,Yakir, Moriya Ben,Sandovski, Daphna,Elgart, Anna,Alpert, Evgenia,Cohen, Guy,Hoffman, Amnon,Katzhendler, Yehoshua,Cerasi, Erol,Sasson, Shlomo
supporting information; experimental part, p. 8096 - 8108 (2009/12/07)
Type 2 diabetes mellitus has reached epidemic proportions; therefore, the search for novel antihyperglycemic drugs is intense. We have discovered that D-xylose increases the rate of glucose transport in a non-insulin-dependent manner in rat and human myot
On the Role of Neighboring Group Participation and Ortho Esters in β-Xylosylation: 13C NMR Observation of a Bridging 2-Phenyl-1,3-dioxalenium Ion
Crich, David,Dai, Zongmin,Gastaldi, Stephane
, p. 5224 - 5229 (2007/10/03)
The role of ortho esters in the formation of 2,3,4-tri-O-benzoyl-β-xylopyranosides from various donor/ promoter pairs has been investigated. It is concluded that for the activation of sulfoxides with Tf2O, thioglycosides with PhSOTf, and bromides with AgOTf the anomeric configuration of the donor is of no consequence on the outcome of the reaction. In all methods studied, the presence or absence of a non-nucleophilic, hindered base is of crucial importance with ortho esters only being discernible in its presence. S-Phenyl 2,3,4-tri-O-benzoyl-1-deoxy-1-thia-β-D-xylopyranoside was synthesized enriched with 13C at each of the three carbonyl carbons. Activation of this thioglycoside with PhSOTf in CD2Cl2 at -78 °C with or without the base permits, for the first time, the observation by 13C NMR spectroscopy of a bridging dioxalenium ion as an intermediate in a neighboring group directed glycosylation. Quenching of this cation in the presence of the base leads to the ortho ester, whereas in the absence of the base the glycosides are the only products detected.
