Syntheses and Biological Evaluations of α- -Mannosyl [60]fullerenols

[60]Fullerenols carrying mono- and bis-α- -mannosyl linkages on the surface were prepared via a [3+2]-cycloaddition reaction between 2-azidoethyl α- -mannoside and C60 followed by polyhydroxylation with aqueous NaOH. Their biological activity was evaluated in terms of binding affinity to lectins by hemagglutination assay and surface plasmon resonance. [60]Fullerenols without the mannosyl linkage caused aggregation of erythrocytes and binding to a β- -galactopyranoside specific lectin (RCA120). In contrast, mono- and bis-mannosyl fullerenols were found to decrease the activity for both aggregating erythrocytes and binding to RCA120, and mono-mannosyl fullerenols turned to binding to α- -mannose specific lectin (Con A).