Synthesis of amphiphilic amino acid C60 derivatives and their protective effect on hydrogen peroxide-induced apoptosis in rat pheochromocytoma cells

Water-soluble fullerene derivatives have often been used as effective scavengers for reactive oxygen species. Three amphiphilic amino acid C60 derivatives, β-alanine C60 derivative, cystine C60 derivative and arginine C60 derivative have been synthesized and characterized. Because of the hydrophobic interaction, the amino acid C60 derivatives could self-assemble to form spherical aggregates. Moreover, the cystine C60 derivative and arginine C60 derivative could further form multilayer vesicles because of hydrogen bonding. Experiments demonstrate that the aggregate morphology could impact the protective effect of amino acid C60 derivatives on apoptosis. These compounds were able to penetrate the cell membrane and reduce the accumulation of reactive oxygen species and cellular damage caused by hydrogen peroxide in PC12 cells. The results suggest that amino acid C60 derivatives have the potential to prevent oxidative stress-induced cell death without evident toxicity. Hence, we hypothesize that the protective effect of amino acid C60 derivatives on hydrogen peroxide induced apoptosis is related to many factors, such as scavenger activity and morphology of the aggregate.