糖基齐聚物紫外线吸收剂设计合成及其构效关系研究

Our research focuses on design and synthesis of a series of new block and asymmetrical dumbbell-shaped oligomeric ultraviolet absorbers with its good biocompatibility based on saccharide, to overcome the drawbacks of the existing ultraviolet absorbers, such as poor hydrophilicity and biocompatibility and skin absorption of ultraviolet absorber with small molecular weight, low effectiveness and sensitivity to electrolyte and pH value of polymeric ultraviolet absorber. The new oligomeric ultraviolet absorbers based on saccharide were synthesized by the reversible addition fragmentation chain transfer living radical polymerization (RAFT) using small molecule of saccharide, benzophenone-type ultraviolet absorbers (UV-A) and cinnamic acid esters ultraviolet absorbers (UV-B)as raw materials, can provide effective protection against both UV-A and UV-B radiation. The controlled ultraviolet absorbers were prepared by control of the backbone of polymer, molecular weight and regulating the numbers, length and ratio of the water-solublepolymerizable saccharide monomer, UV-A monomer and UV-B monomer. In order to find the relationship between structure and properties of the saccharide-based oligomeric ultraviolet absorbers, the ultraviolet light absorption performance and sun protection behavior of the new oligomeric ultraviolet absorbers based on saccharide were investigated. Meanwhile, the simulation are put up, taking solubility parameter, HLB value, and affinity as the starting point. The results obtained may provide some theoretical guidance for the design and synthesis of saccharide-based oligomeric ultraviolet absorbers.

本课题为了克服小分子紫外线吸收剂亲水性差、与其他物质相容性不好、易被皮肤吸收的缺陷，针对现有高分子紫外线吸收剂利用率低以及对电解质和pH值敏感的问题，设计合成一类分子尺寸介于小分子与高分子之间的新型糖基齐聚物紫外线吸收剂SOUAB，其整体结构为嵌段型和非对称哑铃型；同时实现对全波段即UV-A和UV-B段紫外线的高效吸收。拟以小分子糖类、二苯甲酮类（UV-A段）和肉桂酸酯类（UV-B段）紫外线吸收剂为原料，采用可逆加成-断裂链转移自由基活性可控聚合（RAFT）制备SOUAB。通过调节分子主链结构、分子量大小、分子中UVA段和UVB段紫外线吸收剂单元与水溶性糖基单元的个数、长短、比例实现SOUAB结构可控。研究其紫外吸收性能，同时以溶解度参数、HLB、亲和力等物理参数为切入点对整个齐聚物分子进行模拟计算，以明确糖基齐聚物紫外线吸收剂的构效关系，为该类紫外线吸收剂的设计合成提供一定的理论指导。

随着大气臭氧层的破坏日趋严重以及人们自我保护意识的不断加强，使得具有紫外线吸收功能的紫外线吸收剂成为了抗紫外研究的重点。现有小分子紫外线吸收剂虽然具有良好的紫外吸收性能，但却在使用中存在着亲水性差、与其他物质相容性不好、易被皮肤吸收的缺陷，高分子紫外线吸收剂存在利用率低以及对电解质和pH 值敏感的问题，为此，本项目以小分子糖类、二苯甲酮类（UV-A 段）和肉桂酸酯类（UV-B 段）紫外线吸收剂为原料，采用可逆加成-断裂链转移自由基活性可控聚合（RAFT）制备了一类新型糖基齐聚物紫外线吸收剂SOUAB，实现了对全波段即UV-A 和UV-B 段紫外线的高效吸收。主要成果概述如下：（1）制备了一类新型嵌段型和非对称哑铃型主链结构的糖基紫外线吸收剂SOUAB，所制备的糖基紫外线吸收剂具有良好的生物相容性，为生物体相关的紫外线吸收体系提供了一种思路；（2）所制备的糖基紫外线吸收剂SOUAB，实现了对UV-A 和UV-B 段紫外线的高效吸收，为全波段紫外线吸收剂的设计合成提供了重要参考；（3）制备了UV-A 和UV-B 段紫外线吸收剂单体，为其他类聚合物紫外线吸收剂的合成提供了途径；（4）合成了二硫代碳酸酯和三硫代碳酸酯链转移剂，优化了RAFT聚合工艺；（5）通过紫外吸收性能测试，确定了嵌段型和非对称哑铃型主链结构、分子量范围，通过HLB计算，研究了构效关系，对结构优化，能够为该类紫外线吸收剂的设计合成提供一定的理论指导。这些研究成果发表SCI论文12篇，授权专利4件；培养硕士生5人；完成了项目既定的研究工作和任务。