卟啉化合物四-[3-甲氧基-4-(N-咔唑)]正丁氧苯基和四-[3-甲氧基-4-(N-咔唑)]正己氧苯基与小牛胸腺DNA相互作用的研究

〔四-3-甲氧基-4-(N-咔唑)正丁氧苯基]，4C4-TPP〕和〔四-3-甲氧基-4-(N-咔唑)正己氧苯基]，4C6-TPP〕是两个结构相似但侧链不同的卟啉化合物，4C6-TPP的侧链长于4C4-TPP。应用紫外吸收光谱、荧光光谱和园二色谱，研究了4C4-TPP和4C6-TPP与小牛胸腺DNA（Calf thymus, ctDNA）之间的相互作用。结果表明：4C4-TPP和4C6-TPP均以侧链插入DNA与之作用，计算二者与DNA之间的结合常数，4C6-TPP与DNA的结合常数远大于4C4-TPP与DNA的结合常数。基于4C4-TPP与4C6-TPP二者之间结构差异仅在于侧链基团，证明了侧链基团对于卟啉与DNA作用的影响不是主要决定于其空间尺寸大小，取代基化学结构是影响卟啉与DNA的相互作用的重要因素。

Interaction of [3-Methoxy-4- (N-Carbazyl)]N-BuxyloxyPhenyl]Porphyrin and [3-Methoxy-4- (N-Carbazyl)N-Hexyloxyphenyl]Porphyrin with ctDNA

4C4-TPP(meso-tetrakis3-methoxy-4-(N-carbazyl)n-buxyloxyphenyl]porphyrin) and 4C6-TPP (meso-tetrakis 3-methoxy-4-(N-carbazyl)n-hexyloxyphenyl]porphyrin) are similar in structure, but the substitutent size of later is longer than that of former. The interaction of 4C4-TPP and 4C6-TPP with calf thymus-DNA (ctDNA) was explored by UV-vis, fluorescence and circular dichroism spectra. The results demonstrated that the outside of 4C4-TPP and 4C6-TPP binds ctDNA but peripheral substitutents intercalated. The binding constant of 4C6-TPP with ctDNA is greater than that of 4C4-TPP. The difference of binding between 4C4-TPP and 4C6-TPP suggests that the chemical structure of peripheral substitutent plays a more important role than merely their size in determining the binding preferences of porphyrins.