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Relevant academic research and scientific papers

Synthesis and Biological Evaluation of α-D-Mannopyranoside-Containing Dendrimers

The extension of dendritic synthetic principles to the preparation of new kinds of dendrimer-based glycoconjugate systems has been investigated. A convergent growth approach to the synthesis of α-D-mannopyranoside-containing dendrimers of various generations has been used successfully to obtain high molecular weight and monodisperse dendrimers in which 3-36 identical copies of the mannopyranoside residues are located at their peripheries. A repetitive synthetic sequence for forming amide bonds is employed in the preparation of various dendritic wedges and their attachment to a 1,3,5-trisubstituted benzenoid core in the last step. The protecting groups on the saccharide residues are then finally removed to obtain free saccharide-containing dendrimers. The efficacy of these dendrimers in inhibiting the binding of concanavalin A lectin to a purified yeast mannan fraction (as measured by an enzyme-linked lectin assay) is shown to be about four times more pronounced on a molar basis for the dendrimers possessing nine, 18, and 36 mannose residues, when compared to a dendritic wedge possessing three mannose residues and methyl α-D-mannopyranoside as control inhibitors.

Saccharide-modified nanodiamond conjugates for the efficient detection and removal of pathogenic bacteria

The detection and removal of bacteria, such as E. coli in aqueous environments by using safe and readily available means is of high importance. Here we report on the synthesis of nanodiamonds (ND) covalently modified with specific carbohydrates (glyco-ND) for the precipitation of type 1 fimbriated uropathogenic E. coli in solution by mechanically stable agglutination. The surface of the diamond nanoparticles was modified by using a Diels-Alder reaction followed by the covalent grafting of the respective glycosides. The resulting glyco-ND samples are fully dispersible in aqueous media and show a surface loading of typically 0.1 mmol g-1. To probe the adhesive properties of various ND samples we have developed a new sandwich assay employing layers of two bacterial strains in an array format. Agglutination experiments in solution were used to distinguish unspecific interactions of glyco-ND with bacteria from specific ones. Two types of precipitates in solution were observed and characterized in detail by light and electron microscopy. Only by specific interactions mechanically stable agglutinates were formed. Bacteria could be removed from water by filtration of these stable agglutinates through 10 μm pore-size filters and the ND conjugate could eventually be recovered by addition of the appropriate carbohydrate. The application of glycosylated ND allows versatile and facile detection of bacteria and their efficient removal by using an environmentally and biomedically benign material. Copyright

Synthesis of carbohydrate-containing dendrimers. 5. Preparation of dendrimers using unprotected carbohydrates

Carbohydrate-containing dendrimers have been prepared using completely unprotected carbohydrates employing a convergent growth approach. The facile syntheses of lower generation dendrimers, using the amide bond forming methodology, opens up the possibilit