State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China.
J Agric Food Chem. 2011 Aug 24;59(16):8944-52. doi: 10.1021/jf2019006. Epub 2011 Jul 25.
The interaction between farrerol and calf thymus DNA in a pH 7.4 Tris-HCl buffer was investigated with the use of neutral red (NR) dye as a spectral probe by UV-vis absorption, fluorescence, and circular dichroism (CD) spectroscopy, as well as viscosity measurements and DNA melting techniques. It was found that farrerol molecules could intercalate into the base pairs of DNA as evidenced by decreases in iodide quenching effect and single-stranded DNA (ssDNA) quenching effect, induced CD spectral changes, and significant increases in relative viscosity and denaturation temperature of DNA. Furthermore, the spectral data matrix of the competitive reaction between farrerol and NR with DNA was resolved with an alternative least-squares (ALS) algorithm, and the concentration profiles in the reaction and the corresponding pure spectra for three species (farrerol, NR, and DNA-NR complex) were obtained. This ALS analysis demonstrated the intercalation of farrerol to the DNA by substituting for NR in the DNA-NR complex. Moreover, the thermodynamic parameters enthalpy change (ΔH°) and entropy change (ΔS°) were calculated to be -16.49 ± 0.51 kJ mol(-1) and 32.47 ± 1.02 J mol(-1) K(-1) via the van't Hoff equation, which suggested that the binding of farrerol to DNA was driven mainly by hydrophobic interactions and hydrogen bonds.
在 pH 7.4 的 Tris-HCl 缓冲液中，利用中性红（NR）染料作为光谱探针，通过紫外-可见吸收、荧光和圆二色性（CD）光谱、粘度测量和 DNA 融解技术研究了法呢醇与小牛胸腺 DNA 的相互作用。结果表明，法呢醇分子可以嵌入 DNA 的碱基对中，这可以通过碘离子猝灭效应和单链 DNA（ssDNA）猝灭效应的降低、诱导的 CD 光谱变化以及 DNA 相对粘度和变性温度的显著增加来证明。此外，通过交替最小二乘（ALS）算法解析了法呢醇与 NR 与 DNA 之间竞争反应的光谱数据矩阵，并获得了反应中的浓度分布曲线和相应的三种物质（法呢醇、NR 和 DNA-NR 复合物）的纯光谱。该 ALS 分析表明，法呢醇通过取代 DNA-NR 复合物中的 NR 嵌入 DNA 中。此外，通过范特霍夫方程计算得到焓变（ΔH°）和熵变（ΔS°）的热力学参数分别为-16.49±0.51 kJ mol(-1)和 32.47±1.02 J mol(-1) K(-1)，这表明法呢醇与 DNA 的结合主要是由疏水相互作用和氢键驱动的。
