Identification and structural determination of a potent P-selectin inhibitor

Small quantities of a potent P-selectin inhibitor, 2 (IC50 = 0.2 microM), were isolated and an initial structure proposed based on 1D proton NMR. A reterosynthetic analysis of the proposed structure led us to a total synthesis of 2. NMR studies using the 2-D homo-TOCSY and NOESY and 2-D hetero-HMQC helped to confirm the structure of 2.

Design and synthesis of sialyl Lewis x mimics as E-selectin inhibitors

The design and synthesis of novel beta-C-mannosides that inhibit the binding of sialyl Lewis x to E-selectin are described. Compounds that contained a phenyl substituent at the C-6 position were found to have increased potency.

Synthesis of the C'D' disaccharide of aureolic acid

Arylbis(arylthio)sulfonium salts have been used to activate glycals towards nucleophilic addition to form principally 2-deoxy-beta-glycosides. This method was applied to the synthesis of the 2-(methylphenylthio)-2'-phenylthio derivative (22) of methyl O-(4-O-benzyl-2,6-dideoxy-beta-D-arabino- hexopyranosyl)-(1-->3)-3,4-di-O-benzyl-2,6-dideoxy-2,6-beta-D-arabino- hexopyranoside, the C'D' ring analog of an aureolic acid disaccharide. The condensation of 1,5-anhydro-2,6-dideoxy-D-arabino-hex-1-enitol with methanol in the presence of the phenylbis(phenylthio)sulfonium salt resulted in formation of the first beta-glycoside linkage. The methyl 6-deoxyglucoside obtained was deprotected at HO-3 to give the 2-thiophenyl-substituted 2,6-dideoxy-beta-glucoside. This was coupled with 1,5-anhydro-3,4-di-O-benzyl-2-deoxy-D-arabino-hex-1-enitol in the presence of 4-methylphenyl[bis(4-methylphenyl)thio]sulfonium salt to give the (1-->3)-linked disaccharide 22. Finally, desulfurization of 22 using WII Raney nickel generated the required 2,2'-dideoxydisaccharide.