DNA靶向功能的痂囊腔菌素A类光敏剂的设计合成与光动力性质研究

Aimed to improve the photodamage ability of elsinochrome A (EA) under anaerobic circumstance, the derivatives of EA bearing DNA-targeted groups are designed and synthesized, which are based on the factors of the advantage of EA, photodynamic therapy and the feature of cancer growth lack of oxygen. Meanwhile, the actual availability of reactive oxygen species (ROS) increase because the DNA-targeting of derivatives and the adhesion between DNA and derivatives are enhanced. By virtue of the regulation on combining capacity between the derivatives and DNA, the photophysical process transformed and the long lifetime charge-separation state are achieved. Finally, the new type photosensitizer is acquired which can damaged DNA under the low concentration of O2 following the Type I mechanism. Both transient and steady-state spectrums can be used to study the affinity of EA derivatives to DNA. The species of ROS generated by photosensitizer are detected by ESR experiments. Using UV-Vis and fluorescence spectrum, the mutual affinity between the photosensietizers and DNA are carried out in order to elucidate which way and how intensity the mutual affinity to DNA is. Through the laser flash photolysis, the electron which transfers from DNA to photosensitizer are also discussed. In order to enhance the photodamage capability of photosensitizer in anaerobic conditions, the long lifetime triplet charge-separation state are obtained. And the new way that how to improve the photodynamic efficiency is provided by the project.

本项目基于痂囊腔菌素A与光动力疗法的优点，结合肿瘤缺氧生长特点，以调控痂囊腔菌素A缺氧条件下光损伤能力为目标，利用多种DNA分子靶向基团对痂囊腔菌素A进行结构修饰，合成具有DNA靶向功能的痂囊腔菌素A类光敏剂。同时通过增强对DNA的靶向作用和结合能力，还可以提高活性氧物种的实际利用率。申请人期望通过调控光敏剂与DNA分子间结合能力，改变二者间光物理过程，获得长寿命电荷分离态，实现以I型机制为主的光动力过程，得到在缺氧条件下可以有效损伤DNA新型光敏剂。本项目采用ESR等实验方法，确定光敏剂产生活性氧物种的种类与能力。利用紫外光谱与荧光光谱，通过多种实验方法，研究稳态下二者间的相互作用，确定二者间的作用方式与结合能力。采用闪光光解技术，研究瞬态下光敏剂与DNA分子间电子转移性质，通过控制二者间结合能力，得到三重态电荷分离态，增强光敏剂缺氧条件下的光损伤效率，为改善光敏剂光动力效率提供新思路。

本项目基于痂囊腔菌素A与光动力疗法的优点，结合肿瘤缺氧生长特点，以调控痂囊腔菌素A缺氧条件下光损伤能力为目标，利用萘酰亚胺等DNA靶向基团对其进一步修饰，以提高痂囊腔菌素A衍生物与DNA之间的亲合能力，合成得到了多个具有DNA靶向功能的痂囊腔菌素A类光敏剂。采用ESR等实验方法，确定了光敏剂产生活性氧物种的种类与能力。利用紫外光谱与荧光光谱，通过多种实验方法，研究稳态下二者间的相互作用，确定二者间主要通过扦插发生相互作用。结合EB分析法，确定了衍生物在有氧与缺氧条件下的光损伤能力。为了进一步调控痂囊腔菌素A类光敏剂与DNA之间的结合方式，设计合成了4-位和4,5-位双肼基取代的萘酰亚胺类衍生物。以N-丁基-4,5-双肼基-1,8-萘酰亚胺中间体，得到了双水杨酸修饰的萘酰亚胺类衍生物。该化合物对Cu2+表现出了良好的识别能力，在其溶液中加入Cu2+后，其荧光强度明显提高，二者按照1：1发生结合。以罗丹明6G作为母体，合成了多个罗丹明6G衍生物，均对不同金属离子表现出良好的识别能力。结合摩尔比和连续滴定等方法，确定了衍生物与不同金属离子之间的化学计量比。采用核磁滴定和高分辨质谱等方法，研究了衍生物与金属离子之间的作用机理。