Selectin ligands residue

It is useful to visualize, in this context, the selectin ligand glycans sLe , sLe , and 3-sulfate-Le or -Le in relation to the disaccharide segment comprising the nonreducing and subterminal mannosyl residues (a-D-Man-(l 2)-a-D-Man-) of oligoinannoside (Fig. 21C) the CHOH groups C-2 and C-3 of the fucosyl residue... 

Parallel synthesis of 62 different fucosylated tripeptides resulted in two ligands with submicromolar affinity for the P-selectin however, the desired activity for the E-selectin was not observed.98 For the E-selectin selectivity, it was necessary to incorporate a hydroxyl group that mimics the 4-hydroxyl of the central Gal in SLex in addition to a Fuc-residue and a carboxylate to obtain ligands with > 10-fold increased activity over that of the SLex tetrasaccharide.81 One of the best ligands was obtained from Thr(a-Fuc)-OEt, which was first /V-acylated with a hydroxyl amino acid and then elongated with a di-acid to furnish the acid mimic of the sialic acid carboxylate (Fig. 14.4). This approach was further developed as a solid-phase method where the molecule was linked to a solid support through the invariable fucosyl moiety.99... 

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