中文摘要：

采用荧光和紫外（UV）光谱等手段，研究了中药有效成分小檗碱（Ber）与脱氧核糖核酸（DNA）的键合作用。结果发现，小檗碱能插入到DNA双螺旋碱基对之间的空腔中，使小檗碱在λem=530nm处较弱的荧光强度显著提高；酸度显著影响其相互之间的作用；随着DNA浓度的增大，Ber的荧光强度增大，显示了很好的光敏性能。偏振、荧光猝灭实验等也进一步表明：Ber与DNA的作用方式主要是嵌插结合；离子强度的大小会影响Ber与DNA之间的作用。在PH=3．0适宜酸度条件下，建立了以Ber为探针定量测定DNA的分析方法。方法线性范围为0～5．2×10^-5mol／L，精密度（RSD）为2．7％（n=7），检出限为1．43×10^-7mol／L。

英文摘要：

The binding of berberine to calf thymus DNA was investigated by fluorescence and ultravioletvisible absorption spectroscopy. The experimental results revealed that the intercalation of berberine into calf thymus DNA leaded to a dramatic enhancement of the photoluminescence of the drug at 530 nm. The absorption and fluorescence spectra, salt concentration effect, KI quenching, fluorescence polarization and DNA denaturation experiments were given. These results provided the evidence that Ber was inserted into the base stacking domain of DNA double helix. The intrinsic binding constant and the binding site number were estimated. The analytical characteristics were also reported. Linear range was 0-5.2×10^-5 mol/L, precision RSD=2.7%（n=7）, and detection limit was 1.43×10^-7 mol/L.