中文摘要：

通过Bingle环加成反应，利用富勒烯与丙二酸二乙酯催化合成羧酸富勒烯C3，经^1H-NMR，^13C-NMR以及MS-ESI确认其结构和分子量。通过芬顿体系检测了C3清除自由基的能力。利用CCK-8法和Annexin-V／PI染色和流式细胞分析法，分别检测C3对γ射线照射后AHH-1、HIEC细胞存活率，细胞凋亡和细胞周期变化的影响。结果表明，C3具有良好的清除自由基的能力，当芬顿体系中C3终浓度为1000mg／L时，清除效率高达93％左右。对1．12Gyγ射线照射的细胞，C3具有良好的辐射保护作用，表现为照后细胞存活率明显升高，细胞凋亡率显著降低；且对于较高剂量的照射，辐射防护效果较好。说明C3对γ射线照射的细胞具有较好的辐射防护作用，其机理可能主要与其清除自由基的作用有关。

英文摘要：

In this paper the carboxyl-fullerene C3 was synthesized using Bingle＇s cycloaddition reaction and its molecular structure was characterized by ^1H-NMR, ^13C-NMR and MS-ESI. The free radical scavenging ability of C3 was confirmed by ESR in Fenton system. CCK-8 assay, AnnexinV/PI staining and flow cytometry assay were performed to evaluate the cell survival rate, apoptosis and cell cycle alteration after γ-ray irradiation respectively. The results showed that C3 has excellent free radical scavenging ability in Fenton system with a scavenging rate 93 % at the concentration of 1000 mg/L. It has been revealed that C3 has good radioprotection effects to AHH-1 and HIEC cells from radiation damage induced by 1-12 Gy γ-rays in evidence of higher survival and lower apoptosis rate of the cell. The mechanism may be related to its ability of scavenging free radicals.