促神经再生的氮杂类黄酮的设计与合成及其增殖分化机制

Neurodegenerative diseases lead to apoptosis of a large number of neurons. Designing small molecules that promote neurogenesis is crucial to improve the plasticity and function of the brain. Most of the natural bioactive compounds are generally in high oxidation state and free of nitrogen atoms, as restricts their capacity of penetrating through the blood-brain barrier. Previously, we removed the unnecessary the oxygen atoms from the natural stilbenes and chalcones followed by insertion of the required nitrogen atoms being a component of the pharmacophore, which led to enhance of the potency of promoting neurogensis. Therefore ,we proposedwhether we could build and uncover a new three-dimensional pharmacophore to promote neurogenesis via the deoxy-aza transformation of natural flavonoids sharing similar biosynthetic pathway with stilbenes. In this proposal, we will investigate the deoxy-aza routes to construct pharmacopores with the help of computer-aided design, and by this way the resulted compounds get easier to penetrate the blood-brain barrier. The optimized aza-flavonoids with good pharmacophoric conformation are accomplished by means of conformation restriction and skeleton hopping. Then, the structure-activity relationship and structure-property relationship will be illustrated in detail at the stages of cellular proliferation and differentiation. Next, differential proteomics analysis would tell expressing levels' changes of both the key signaling proteins and micro-environmental factors that have great impacts on proliferation and differentiation of endogenous stem cells. Investigation on underlying mechanism that regulates signaling proteins plus micro-environmental factors would be carried out for further rational structural modification. In combination with other kinds of biochemical technology, the mechanism of the pharmacophore interacting with the potential (multi)targets that effect on proliferation and differentiation could be revealed. This study will surmount the structural limitation of the natural skeleton, namely excessive oxygens and free of nitrogens, and pave the way for the rational design of novel candidates that stimulate the neurogenesis effectively and in situ.

神经退行性疾病导致神经元大量凋亡，设计小分子促神经再生成为重塑大脑功能的关键。天然活性成分多呈无氮原子的高氧化态，制约了其血脑屏障通过能力。前期课题组对天然二苯乙烯和查耳酮去氧-氮杂，不但提高其促神经再生活性还发现含氮取代基为药效团的重要组成。故本申请提出：能否通过去氧-氮杂改造骨架同源的天然类黄酮来构建并阐明促神经再生的三维药效团？项目拟借助计算机辅助设计，研究去氧-氮杂类黄酮合成方法，优化其血脑屏障通过能力，通过构象限制和骨架跃迁探索能达到最优药效构象的氮杂类黄酮骨架，阐明增殖和分化阶段的构效关系和构性关系；差异蛋白质组学分析增殖分化信号通路蛋白和微环境因子的变化规律，探索调控信号蛋白与调控微环境因子相结合的结构修饰策略，并结合其它多种生化手段揭示调控增殖和定向分化的（多）靶标与药效团相互作用机制。该研究将突破天然骨架的多氧缺氮的结构缺陷，为原位、高效促神经再生分子的理性设计奠定基础。

紫檀芪促进神经发生，但是难以通过血脑屏障。我们通过合成二苯乙烯、二苯丙烯、二苯丙烯腈、二苯二亚基胺等骨架，同时改变苯环上的含氮取代基进行构效关系研究，阐明了最优骨架和取代基。通过免疫组化染色证明优化的化合物不但可以通过血脑屏障促进海马区祖细胞增殖还可以定向神经元分化。此类化合物可以改变抑郁鼠的神经发育并提高抗抑郁效果。此外，发现促神经发生药物兼具抗炎活性，在此基础上我们结合计算机辅助设计阐明了构效关系，将活性比先导化合物提高了百倍（纳摩尔）。本项目中合成了近百化合物，最终获得了体内具有促神经发生活性和抗炎活性化合物，可为今后抗神经退行性疾病的临床前研究奠定基础。