Combinatorial and in situ Approachies to Lead and Refined Compounds

在上一个资助期，发现了GABAB受体的第一个小分子正调节剂，并且发现正调节是一种可行的策略，用于逆转动物模型中与尼古丁依赖相关的行为，同时最大限度地减少不良副作用。有了这个应用程序，我们寻求资源，以继续开发GABA{B}受体阳性调节剂，并了解更多有关其作用机制。项目1的目标是完成现有嘧啶基化合物的精制，并找到具有更好性能的替代结构。遵循一 详细的结构-活性研究，提出了对嘧啶结构的某些关键位置进行修饰，以增加溶解度，同时保持亲和力。我们还将同时努力通过用在类似方向上显示官能团的杂环取代中心嘧啶环来产生新的先导结构。在所有情况下，合成路线都是短的，高产的，并容忍不同的功能，以使其易于优化铅结构。另外两条发现线也将继续进行。第一个利用了在斯克里普斯佛罗里达，这将是挖掘的相似性建模成功的正调制器结构在项目2的大型化合物集合。将筛选最终的候选人，并将新的牵头人纳入项目1的综合和测试周期。此外，我们将采用靶向合成技术，将本计划中已经开发的正调节剂转化为GABA{B}受体的双位点结合剂。这种方法使用高度选择性的连接反应，仅当同时结合到靶蛋白上的相邻位点时才连接小分子，从而产生高亲和力和选择性的二价配体。所有新化合物将在Finn实验室通过受体结合试验进行筛选，并在项目2中通过第二信使和信号传导试验进行筛选。 通过与项目2的体外测试、体内药理学和生物信息学能力的密切合作，将确定并改进最佳化合物，以获得项目3中尼古丁依赖动物模型行为研究的优化结构。

In the previous funding period, the first small-molecule positive modulators of the GABAB receptor were discovered, and positive modulation was found to be a viable strategy for reversing behaviors with relevance to nicotine dependence in animal models, while minimizing undesired side-effects. With this application, we seek the resources to continue the development of GABA{B} receptor positive modulators and learn more about their mechanism of action. The goals of Project 1 are to complete the refinement of the existing pyrimidine-based compounds and to find alternative structures with even better properties. Guided by a detailed structure-activity study, modifications certain key positions of the pyrimidine structure are proposed to increase solubility while retaining affinity. We will also mount a parallel effort to generate new lead structures by replacing the central pyrimidine ring with heterocycles that display functional groups in similar orientations. In all cases, the synthetic routes are short, high-yielding, and tolerant of diverse functionality, in order to make it easy to optimize lead structures. Two additional lines of discovery will also be pursued. The first takes advantage of the large compound collection at Scripps Florida, which will be mined by similarity modeling to successful positive modulator structures in Project 2. The resulting candidates will be screened and new leads will be incorporated into the synthesis and testing cycle of Project 1. In addition, we will employ the technique of target-guided synthesis to convert the positive modulators already developed in this program into two-site binders to the GABA{B} receptor. This approach uses a highly selective connecting reaction to join small molecules only when simultaneously bound to adjacent sites on the target protein, giving rise to bivalent ligands of high affinity and selectivity. All new compounds will be screened by a receptor binding assay in the Finn laboratory and by second messenger and signaling assays in Project 2. By close collaboration with the in vitro testing, in vivo pharmacology, and bioinformatics capabilities of Project 2, the best compounds will be identified and refined to arrive at optimized structures for behavioral studies in animal models of nicotine dependence in Project 3.