染料木素及其葡萄糖苷与DNA相互作用的研究  

Research on the Interactions between Genistein and Its Glucosides with DNA

作　　者：李华[1] 余燕影[1] 胡昕[1] 曹树稳[1,2] 

机构地区：[1]南昌大学化学系,江西南昌330031 [2]食品科学与技术国家重点实验室,南昌大学,江西南昌330047

出　　处：《光谱学与光谱分析》2008年第8期1905-1909,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(20562008);长江学者和创新团队发展计划项目(IRT0540)资助

摘　　要：在pH7.2 Tris缓冲溶液中,采用紫外、荧光、粘度等方法研究了染料木素、染料木素葡萄糖苷、染料木素7,4’-二-O-β-D-葡萄糖苷与小牛胸腺ctDNA的作用。结果表明,在ctDNA存在下,染料木素及其葡萄糖苷的紫外吸收光谱的最大吸收峰均产生明显的减色效应。三种化合物的加入均能有效猝灭EB-DNA体系的荧光,而猝灭方式并不唯一。另外,ctDNA溶液的粘度也都随三种化合物的加入而增大。据此推断,染料木素及其葡萄糖苷与ctDNA之间具有较强的作用,可能以部分插入及氢键作用与ctDNA结合,其作用强弱顺序为染料木素葡萄糖苷>染料木素7,4’-二-O-β-D-葡萄糖苷>染料木素。结果提示染料木素的7位或4’位葡萄糖基化修饰有望作为抗癌活性候选物,值得进一步深入研究。The interactions of genistein （GEN）, genistein glucoside （GENG） and genistein 7,4 ＇-di-O-β- D- glucoside （GEND） with calf thymus DNA（ctDNA） in Tris （pH 7. 2） buffer were investigated by UV spectra, fluorescence spectra and viscosity. From the absorption titration experiments, no obvious red shifts were found, but the notable hypochromicities were observed. The π→π＇ transitions of GEN at 262 nm showed a 10% decrease in intensity at [GEN]/[DNA]=2, and for the GENG and GEND, the decreases were 24. 8% and 18% at 260 and 258 nm, respectively. These results indicated that there were intercalations between these compounds and ctDNA, involving a strong a-stacking interacting. The hypochromism of the two glucosides was bigger than that of GEN, which suggested that the two glucosides intercalated deeply into the DNA base pairs. The emission intensity of DNA-EB system at 600 nm decreased remarkably with increasing the three compounds, indicating that these compounds could intercalate into DNA and replace EB from the DNA-EB system. And at 25 and 37 ℃, the fluorescence quenching curves of these compounds with DNA-EB system were not linear curves. According to the classical Stern-Volmer equation, it was not single static or dynamic quenching model, so there would be hydrogen bonding besides intercalation, Viscosity experiments were carried out by an Ubbelodhe viscometer at （20. 0±0. 1）℃. The relative viscosity of ctDNA increased steadily with increasing these compounds. The results clearly showed that these compounds could intercalate between DNA base pairs, causing an extension of the helix, and thus increased the viscosity of DNA. And because of the greatest increase in viscosity of the DNA, the interaction of GENG with DNA was the strongest, followed by GEND, and then GEN. The results were consistent with the above spectral results. These results suggested that genistein and its glucosides could bind to ctDNA partly by intercala- tion and hydrogen bonding mode, and the binding ability t

关 键 词：染料木素 葡萄糖苷 小牛胸腺DNA 

分 类 号：O657.3[理学—分析化学] Q523[理学—化学]