Synthesis of Spacer-Armed Glucodendrimers Based on the Modification of Poly(propylene Imine) Dendrimers

Abstract

The use of preformed poly(propylene imine) dendrimers surface concentration variations on the dendrimer properties. After modification of the dendrimers with these saccharide [DAB(Pa) x ] with reactive primary amine end groups proved to be very useful for the construction of saccharide surface-units, the acetyl protecting groups were removed.Purification of these derivatives was accomplished by using coated dendrimers. For this purpose, amide bonds were introduced by a reaction between the primary amine end dialysis either in water or in aqueous methanol. The solubility behavior of the resulting glucodendrimers proved groups of the dendrimers with N-succinimidyl-activated esters of spacer-armed acetyl-protected thioglucopyranoside to be strongly dependent on the hydrophobic part, i.e. the alkyl chain spacers in the molecule. Therefore, these units. The linear alkyl chain spacers between the dendrimer surface and the saccharide units was increased in length with nanosized multivalent structures, appropriate for studying carbohydrate-protein interactions, are also proposed useful 1, 5 and 10 carbon atoms. These spacer arms were introduced to determine the influence of local saccharide for investigating amphiphilic properties. When functionalized nanosized globular structures are de-Since the first patents lodged by Denkewalter, [14] many sired, mostly divergently synthesized dendrimers such as the macromolecular components have been reported based on PAMAM [2] , arborols [3] and the poly(propylene imine) dendendrimers incorporating biologically active entities such as drimers [4] are employed, because of their availability on a antibodies, [15] amino acids, [11] [16] oligonucleotides [17] and reasonably large scale, even for higher generations of denmono-and oligosaccharide residues. [18] In recent years, sevdrimers. Modification of the end groups of these dendrieral groups have described [19] [20] [21] [22] [23] their particular mers has received enormous attention and has led to the approaches to the construction of carbohydrate-containing disclosure of the dendritic box [5] , the unimolecular (indendrimers or Ϫ as they have become known Ϫ glycodenverted) micelle [6] and metallodendrimers, [7] leading to applidrimers. [24] This new family of neoglycoconjugates has procations foreseen [8] in areas like (chiral) clathration, [9] catalyved to be extremely useful when studying multiple carbosis [10] and biology. Many of the unique dendritic properties, hydrateϪprotein interactions. The enhancement in binding like guest-host interactions and dense surface packing, only of saccharide residues to protein receptors as a result of arise at higher generations of dendrimers, indicating that increasing the saccharide "valency" is a well-known cooperative effects are present in these nanosized strucphenomenon in glycobiology [25] which is often referred to tures. [9] [11] [12] These cooperative recognition effects are even as the cluster glycoside or multivalency effect. It has already more prominent in biological s...

OC018: Should complete miscarriages be followed up with serum human chorionic gonadotrophin levels?

“…12 A further advantage of this methodology is that the stereochemistry at the important anomeric center is established at an early stage in the synthetic sequence. Even under more basic conditions, the stereochemical integrity at the anomeric center of the 1‐thiosugars is maintained 28…”

The Cluster Glycoside Effect

“…In contrast to the PAMAM ligands, these compounds are stable to β-elimination. Fraser Stoddart and co-workers have incorporated up to 64 lactose moieties into the preformed dendrimer core, adding saccharide ligands as the N -hydroxysuccinamide esters. , Thompson and Schengrund have used the same core to display the GM1 pentasaccharide in the preparation of multivalent ligands for the Escherichia coli heat-labile toxin . The iminobis(propylamine) core has also been used for glycodendrimer synthesis.…”

Biohybrid Polymer Capsules

“…Various examples exist of high valent carbohydrate dendrimers designed to use the cluster effect. The group of Meijer synthesized a PPI-carbohydrate dendrimer, in which the 64 terminal saccharides were separated from the dendrimer by a methylene spacer. Roy and co-workers synthesized a lactose functionalized PAMAM dendrimer, with up to 128 terminal carbohydrates .…”