利用自由基聚合反应合成了聚丙烯酸修饰的富勒烯(C60-PAA),进一步通过酯化反应将核黄素类似物6,7-二甲基-9-(2'-羟乙基)-异咯嗪(DHIX)与C60-PAA共价连接,得到C60-PAA-DHIX.利用傅立叶红外光谱(F-IR)、核磁共振氢谱(1HNMR)、紫外-可见吸收光谱(UV-Vis)、荧光光谱对产物的化学结构进行了表征.循环伏安法表明,C60-PAA-DHIX中富勒烯基团的第一还原电位要高于DHIX基团的第一还原电位.ESR实验表明C60-PAA-DHIX能与N,N-二甲基苯胺发生多步光诱导电子转移反应,即DHIX基团与N,N-二甲基苯胺发生光诱导电子转移生成DHIX负离子自由基(DHIX-·),DHIX-·能进一步将电子传递给富勒烯生成富勒烯负离子自由基.DNA熔解曲线、紫外-可见吸收光谱和荧光光谱结果表明,C60-PAA-DHIX通过沟槽结合与CTDNA作用,而C60-PAA与DNA的作用较弱.无氧条件下,C60-PAA-DHIX具有比C60-PAA更强的DNA光损伤能力.%Poly (acrylic acid) conjugated fullerene (C60-PAA) is synthesized by free-radical po1ymerization. C60-PAA is covalently linked with riboflavin analogue 6, 7-Dimethyl-9-( 2'hydroxyethyl)-isoalloxazine through esterification reaction, affording C60-PAA-DHIX. The products are characterized by Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (1 H NMR), UV-visible absorption spectroscopy (UV-Vis), and fluorescence spectroscopy. Cyclic voltammetry results show that the first reduction potential of fullerene moiety is higher than that of DHIX moiety in C60-PAA-DHIX. ESR results indicate that multi-step photoinduced electron-transfer processes may occur between C60-PAA-DHIX and N, N-dimethyl aniline under irradiation. One-electron transfer from N, N-dimethyl aniline to excited-state DHIX induces the generation of DHIX-. radical, followed by electron transfer from the DHIX-. radical to C60, forming the corresponding anion radical of C60 (C60-.). The results obtained from DNA melting experiments, UV-Vis absorption and fluorescence spectra suggest that C60-PAA-DHIX could interact with CT DNA through groove binding mechanism.However, C60-PAA can only weakly interact with DNA. C60-PAA-DHIX exhibited stronger DNA photodamage ability on plasma DNA than C60-PAA under anaerobic condition.
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