Abstract: Fullerene has been chemically functionalized by covalent attachment of different adducts onto the parent cage, to improve its solubility in polar organic solvents or to prepare aqueous solutions. This would be helpful for studying the biological activities of fullerene derivatives and their potential application in the biomedical field. N-Substituted 3,4-fullero pyrrolidine was synthesized via 1,3-dipolar cycloaddition of the azomethine ylide. Aspartic acid and glutamic acid with protected α-amino and α-carboxyl groups were reacted with the activated hydroxyl group of N-substituted 3,4-fullero pyrrolidine, respectively. The products were then deprotected, affording two novel fullerene α-amino acids, fullerene aspartic acid and fullerene glutamic acid. Their chemical structures were characterized via MALDI-TOF-MS, UV-Vis, FTIR and ¹H NMR. Furthermore, the aqueous nanoparticle suspensions of these fullerene amino acids were obtained by the method of organic solvent exchange, characterized by electron microscopy and zeta-potential analysis. The nanoparticle sizes of both fullerene amino acids were around 100 nm, with zeta-potentials of about 27 mV. The results indicate that these aqueous suspensions were rather stable with considerably homogeneous shape and size of nanoparticles, and thus were worthy of further investigating their potential application in the biomedical field.

Key words: Fullerene α-amino acids, Nanoparticle aqueous suspension, Addition reaction, Condensation reaction