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目的 测定苯醌 (BQ)与脱氧鸟苷酸 (dGMP)反应形成的加合物结构与化学特性。方法高效液相色谱 质谱联机技术及紫外分光光度法。结果 苯醌与脱氧鸟苷酸反应形成两种可检测的加合物Ad1 和Ad2 ,质谱显示Ad1 的分子量为 437,在不同pH条件下的特征紫外吸收光谱及结合键类型测定结果表明 ,Ad1 为BQ与dGMP共价结合而成 ,推测结合位点在dGMP的N 1和N2 位 ,分子式为C1 6 H1 6 O8N5P。BQ与小牛胸腺DNA反应水解产物经高效液相色谱 (HPLC)分离同样检出了与Ad1 具有相同保留时间的化合物。Ad2 分子量为 2 4 1 ,其分子式为C1 1 H7O2 N5,可能是由BQ进攻dGMP的N 9位并脱掉糖基所得。结论 苯醌可在体外试管反应条件下形成DNA加合物 ,其中一种主要的加合物结构为 (3’ 羟基 ) 1 ,N2 苯乙烯基 2’ 脱氧鸟苷 5’ 磷酸
Objective To determine the structure and chemical properties of adducts formed by the reaction of benzoquinone (BQ) with deoxyguanosine (dGMP). Methods High performance liquid chromatography-mass spectrometry online and UV spectrophotometry. Results The benzoquinone and deoxyguanosine reacted to form two detectable adducts, Ad1 and Ad2. The mass spectrometry showed that the molecular weight of Ad1 was 437. The characteristic UV absorption spectra and the type of binding bonds at different pH showed that Ad1 was BQ was covalently bound to dGMP, suggesting that the binding site is at the N1 and N2 positions of dGMP with the formula C1 6 H1 6 O8N5P. BQ and calf thymus DNA hydrolysates were also separated by high performance liquid chromatography (HPLC). Compounds with the same retention time as Ad1 were also detected. Ad2 has a molecular weight of 2 4 1 and its molecular formula is C1 1 H7O2 N5. It is probable that BQ attacked the N 9 position of dGMP and removed the glycosyl residue. CONCLUSION Benzoquinone can form DNA adducts under in vitro tube reaction conditions. One of the major adduct structures is (3 ’hydroxyl) 1, N2 styryl 2’ deoxyguanosine 5 ’phosphate