title: Glycoside and peptide clustering around the octasilsesquioxane scaffold via photoinduced free-radical thiol-ene coupling. The observation of a striking glycoside cluster effect.
abstract: Two series of multivalent octasilsesquioxane glyco- and peptido-conjugates were synthesized using the photoinduced free-radical thiol-ene coupling (TEC). The first series was obtained by coupling C-glycosylpropyl thiols and cysteine containing peptides with the known octavinyl octasilsesquioxane while the second series was obtained by reacting glycosyl thiols with a new octasilsesquioxane derivative displaying eight PEGylated chains functionalized with terminal allyl groups. The evaluation of the binding properties of mannoside and glucoside clusters toward Concanavalin A by Enzyme-Linked Lectin Assay (ELLA) revealed a modest glycoside cluster effect. On the other hand, the PEGylated POSS-based glycocluster featuring eight N-acetyl-glucosamine residues showed high affinity toward Wheat Germ Agglutinin to give a measured IC(50) at 3 nM. The calculated relative potency per number of sugar unit (rp/n) was superior to a value of 10(6), thus revealing the occurrence of a striking glycoside cluster effect.
authors.affiliation: Dipartimento di Chimica, Laboratorio di Chimica Organica, Università di Ferrara, Via L. Borsari 46, 44100 Ferrara, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Lo Conte
authors.forename: Samuele
authors.initials: S
authors.lastname: Staderini
authors.forename: Angela
authors.initials: A
authors.lastname: Chambery
authors.forename: Nathalie
authors.initials: N
authors.lastname: Berthet
authors.forename: Pascal
authors.initials: P
authors.lastname: Dumy
authors.forename: Olivier
authors.initials: O
authors.lastname: Renaudet
authors.forename: Alberto
authors.initials: A
authors.lastname: Marra
authors.forename: Alessandro
authors.initials: A
authors.lastname: Dondoni
mesh_terms: D005609:Free Radicals / Q000737:chemistry*; D006027:Glycosides / Q000138:chemical synthesis / Q000737:chemistry*; D017646:Organosilicon Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry*; D055668:Photochemical Processes; D013438:Sulfhydryl Compounds / Q000737:chemistry
chemical_list: D005609:Free Radicals; D006027:Glycosides; D017646:Organosilicon Compounds; D010455:Peptides; D013438:Sulfhydryl Compounds