851857-30-2

Upstream product

• 3068-32-4 1-bromo-2,3,4,6-tetra-O-acetyl-D-galactopyranose 
• 501-53-1 benzyl chloroformate 
• 25878-60-8 D-galactose pentaacetate 
• 504-91-6 (5R)-5-hydroxy-L-lysine 

Downstream Products

• 270089-67-3 (5R)-N^α-(fluoren-9-ylmethoxycarbonyl)-N^ε-benzyloxycarbonyl-5-O-(2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl)-5-hydroxy-L-lysine 

Relevant academic research and scientific papers

Probing molecular interactions within class II MHC Aq/ glycopeptide/T-cell receptor complexes associated with collagen-induced arthritis

T cells obtained in a mouse model for rheumatoid arthritis are activated by a glycopeptide fragment from rat type II collagen (CII) bound to the class II major histocompatibility complex Aq molecule. We report a comparative model of Aq in complex with the glycopeptide CII260-267. This model was used in a structure-based design approach where the amide bond between Ala261 and Gly262 in the glycopeptide was selected for replacement with ψ[COCH2], ψ[CH2NH 2+], and ψ[(E)-CH=CH] isosteres. Ala-Gly isostere building blocks were then synthesized and introduced in CII260-267 and CII259-273 glycopeptides. The modified glycopeptides were evaluated for binding to the Aq molecule, and the results were interpreted in view of the AVglycopeptide model. Moreover, recognition by a panel of T-cell hybridomas revealed high sensitivity for the backbone modifications. These studies contribute to the understanding of the interactions in the ternary A q/glycopeptide/T-cell receptor complexes that activate T cells in autoimmune arthritis and suggest possibilities for new vaccination approaches.

Mild oxidative cleavage of 9-BBN-protected amino acid derivatives

Protection of the amino acid moiety using 9-BBN is an effective method to enable side chain manipulations in synthesis of complex amino acids. We investigated the standard, mild method for deprotection of the 9-BBN group in methanolic chloroform, and found that it relies on a slow oxidation mediated by molecular oxygen. Building on this insight, we have developed a method that allows for a fast and selective deprotection using simple peroxy acid reagents. After Fmoc protection, products were isolated in >90% yield for a series of amino acid derivatives, including a galactosylated derivative of hydroxylysine. A representative set of 9-BBN-protected amino acid derivatives were efficiently deprotected using peracid reagents in excellent yields. Deprotection is orthogonal with several common protecting groups. Its tolerance of highly acid sensitive groups, such as trityl-protected amides and glycosidic linkages, is especially notable.

9-BBN as a convenient protecting group in functionalisation of hydroxylysine

9-BBN was used for regioselective protection of the α-amino and α-carboxyl groups of (5R)-5-hydroxy-L-lysine. The resulting 9-BBN complex was then employed in transformations such as N-Cbz protection, azido transfer, O-glycosylation, and O-silylation. Further manipulations led to improved methods for preparation of hydroxylysine and galactosylated hydroxylysine building blocks, suitable for direct use in peptide synthesis under standard Fmoc conditions.