The 61-bis(1-adamantylcarbamoyl)-1,2-methano[60]fullerene was synthesized from N,N'-di(1-adamantyl)malondiamide and C(60) in the presence of 1,8-diazabicyclo[5,4,0]-7-undecene. The intraperitoneal administration of this fullerene derivative (10mg/kg) caused an antagonistic effect on