7-羟基黄酮及磷酰化7-羟基黄酮与DNA的弱相互作用荧光法研究

Study on the Non-Covalent Interaction of 7-Hydroxy Flavone and Its Phosphate with DNA by Fluorescence Method

以溴化乙锭(EB)为荧光探针,研究了7-羟基黄酮及磷酰化7-羟基黄酮与DNA的弱相互作用。实验结果表明,两种化合物与DNA间均存在弱相互作用,但与7-羟基黄酮相比,磷酰化7-羟基黄酮对DNA更具亲和力。随着温度的升高,7-羟基黄酮及磷酰化7-羟基黄酮对DNA-EB体系的荧光猝灭常数降低,两种化合物均可与DNA形成复合物,此猝灭过程为静态猝灭。根据Stern-Vol mer方程和Scatchard方程,常温下7-羟基黄酮及磷酰化7-羟基黄酮对DNA-EB体系的荧光猝灭常数和它们与DNA的固有的结合常数分别为Kq1=601L.mol-1,Kq2=1381L.mol-1;K1=2.07×104L.mol-1,K2=3.19×104L.mol-1。

The non-covalent interaction of 7-hydroxy flavone and its phosphate with DNA was studied using ethidium bromide （EB）as a probe. The result showed that both 7-hydroxy flavone and its phosphate could form non-covalent complexes, but the phosphorylated flavonoid showed higher binding affinity with DNA than 7-hydroflavone did. Experiments demonstrated that the higher the temperature, the lower the slop of quenching curve of DNA-EB in the presence of different amounts of 7-hydroxy flavone and its phosphate. It was confirmed that the combinations of DNA with 7-hydroxy flavone and its phosphate were a single static quenching process. According to the Stern-Volmer equation and Scatchard equation the quenching constants and the intrinsic binding constants of 7-hydroxy flavone and its phosphate were measured respectively, they were Kq1 = 601 L ·mol^-1 , Kq2 =1 381 L·mol^-1 ; K1 =2. 07×10^4 L·mol^-1 , K2=3.19×10^4 L · mol^-1 respectively.