Standardized intermediates for oligosaccharide synthesis. A convenient preparation of partially protected derivatives of allyl O-β-d-galactopyranosyl-(1 → 4)-β-d-glucopyranoside suitable for chain extension at position O-4′

Youssef, Rimon H.; Silwanis, Basim Azmy; El-Sokkary, Ramadan I.; Nematalla, Asaad; Nashed, Mina A.

doi:10.1016/0008-6215(93)84191-8

Cited by 20 publications

(7 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The ring-opening metathesis polymerization (ROMP) is a versatile method to generate multivalent, biologically active displays; 1 consequently, we applied this method to generate a lactose-substituted array. A suitable monomer could be obtained from the known peracetylated b-allyl lactopyranoside 12 upon ozonolysis followed by sodium borohydride reduction to unmask the primary alcohol 3. This alcohol underwent a Mitsunobu reaction with the cyclic imide template 2 13 to produce 4 (Scheme).…”

Section: Figurementioning

confidence: 99%

See 1 more Smart Citation

Scope of Multivalent Ligand Function: Lactose-Bearing Neoglycopolymers By Ring-Opening Metathesis Polymerization

Pohl¹,

Kiessling

1999

Synthesis

View full text Add to dashboard Cite

A lactose-bearing norbornene imide template was polymerized using (Cy 3 P) 2 Cl 2 Ru=CHPh to produce a lactose-substituted neoglycopolymer. The resulting polymer showed a 100-fold overall increase in inhibitory potency (5-fold increase on a per saccharide residue basis) compared to monomeric lactose in both a galectin-binding assay and an Erythrina corallodendrum hemagglutination assay.The relatively low affinity and specificity of individual carbohydrate-protein interactions is hard to reconcile with the diversity of oligosaccharide structures that are involved in specific recognition processes. Many scientists resolve this paradox with the assumption that multiple carbohydrate-protein interactions can cooperate in each recognition event to give the necessary functional affinity. 1,2 By changing the number of individual interactions as well as controlling their spatial arrangement, a multivalent ligand can become specific to a target or targets. Because protein-carbohydrate complexation is important in a wide range of medically significant interactions including inflammation and bacterial and viral pathogenesis, an understanding of multivalent recognition events is critical for designing therapeutics that target these processes. 3 Multivalent interactions are paramount in a variety of physiological processes, yet relatively little is known about these binding events. For example, much work has been done in elucidating the specific monovalent interactions between carbohydrate ligands with specific proteins such as the cell-surface selectins, 4 the galectins, 5 and various plant lectins, 6 yet an understanding of the contribution of polyvalent interactions to the functional affinity and specificity of these processes is only beginning to emerge. To build on our studies of multivalent saccharide derivatives, 7-10 we decided to explore the inhibitory properties of polymeric ligands that display a high local concentration of saccharide epitopes in assays with two different lectins.Several mechanisms may operate to enhance the functional affinity (i.e., the measured activity) of a particular multivalent ligand. Two such mechanisms include the chelate effect and the statistical effect due to high local concentration. In the chelate effect, a multidentate ligand occupies multiple binding sites within a protein (Figure 2A). The statistical effect we refer to is that in which ligands that present a high local concentration of saccharide epitopes to a single binding site exhibit slower off rates ( Figure 2B). To test the contributions of these effects to saccharide recognition, we chose to explore galectin-3 (Gal-3) and the lactose-binding lectin from Erythrina corallodendrum (EcorL). The galectins, like the selectins, have been implicated in the inflammatory response. Some of the naturally occurring ligands that bind the galectin family of proteins consist of polylactosamine units found in glycoconjugates such as fibronectin and laminin. 11 The structures of naturally occurring galectin ligands suggests multidentate inhi...

show abstract

Section: Figurementioning

confidence: 99%

“…A solution of allyl O- (2,3,4,6- 12 in MeOH (3.0 mL), and CH 2 Cl 2 (13.0 mL) at -78°C was treated with ozone until the solution turned blue. The solution was sparged with N 2 to remove excess ozone.…”

Section: -Hydroxyethyl O-(2346-tetra-o-acetyl-b-d-galactopyranosymentioning

confidence: 99%

Scope of Multivalent Ligand Function: Lactose-Bearing Neoglycopolymers By Ring-Opening Metathesis Polymerization

Pohl¹,

Kiessling

1999

Synthesis

View full text Add to dashboard Cite

show abstract

“…(C B (3)), 70.6 (C A (3)), 68.9 (C B (2)), 66.9 (C B (4)), 61.7 (C A (6)), 61.5 (C B (6)), 55.3 (C A (2)), 25 (11). Monohydroxy derivative 10 (130 mg, 0.16 mmol) was acetylated with acetic anhydride (800 L) in pyridine (1.5 mL) at room temperature for 12 h. Then, the mixture was concentrated, the residue was dissolved in toluene, and the solvent was evaporated (3×5 mL).…”

Section: Methodsmentioning

confidence: 99%

“…Benzoyl chloride (5 mL, 43.20 mmol) was added dropwise to a solution of allyl lactoside 13 (2.40 g, 5.68 mmol) (see Ref. 25) in pyridine (15 mL) at 4 C, and the reaction mixture was allowed to stand for 2 h at this temperature and for 16 h at room temper ature. Methanol (1 mL) was added, the mixture was diluted with chloroform (100 mL), washed with 1 M aqueous H 2 SO 4 (3×50 mL), water, and saturated aqueous NaHCO 3 (3×50 mL).…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Synthesis of oligosaccharide fragments of the Streptococcus pneumoniae type 14 capsular polysaccharide and their neoglycoconjugates with bovine serum albumin

et al. 2014

View full text Add to dashboard Cite

show abstract

ChemInform Abstract: Standardized Intermediates for Oligosaccharide Synthesis. A Convenient Preparation of Partially Protected Derivatives of Allyl O‐β‐D‐ Galactopyranosyl‐(1 → 4)‐β‐D‐glucopyranoside Suitable for Chain Extension at Position O‐4′.

Youssef¹,

Silwanis²,

El-Sokkary³

et al. 1993

ChemInform

View full text Add to dashboard Cite

show abstract

Standardized intermediates for oligosaccharide synthesis. A convenient preparation of partially protected derivatives of allyl O-β-d-galactopyranosyl-(1 → 4)-β-d-glucopyranoside suitable for chain extension at position O-4′

Cited by 20 publications

References 14 publications

Scope of Multivalent Ligand Function: Lactose-Bearing Neoglycopolymers By Ring-Opening Metathesis Polymerization

Scope of Multivalent Ligand Function: Lactose-Bearing Neoglycopolymers By Ring-Opening Metathesis Polymerization

Synthesis of oligosaccharide fragments of the Streptococcus pneumoniae type 14 capsular polysaccharide and their neoglycoconjugates with bovine serum albumin

ChemInform Abstract: Standardized Intermediates for Oligosaccharide Synthesis. A Convenient Preparation of Partially Protected Derivatives of Allyl O‐β‐D‐ Galactopyranosyl‐(1 → 4)‐β‐D‐glucopyranoside Suitable for Chain Extension at Position O‐4′.

Contact Info

Product

Resources

About