新颖抗抑郁活性化合物paeoveitol作用靶点及结构优化研究

Depression is one of the mental illness that seriously endangers people's physical and mental health. Currently, synthetic antidepressants are clinically useful but suffering from various shortcomings including slow onset of action, unwilling side effects. Thus, the search for new antidepressants with rapid onset and low toxicity is ever increasing. Our previous chemical investigation of traditional Chinese medicine Paeonia veitchii led to the isolation of a pair of structurally novel norditerpene paeoveitol enantiomers, then we accomplished the first enantioselective total synthesis of (+)- and (−)-paeoveitol on decagram scale. Subsequent biologically active investigations found (+)-paeoveitol showed notably antidepressant effect by significantly reduce immobility time of mice in the forced swimming test, which is comparable to the positive drug fluoxetine under the same dose (60 μmol/kg). In this project, therapeutic target studies on (+)-paeoveitol with antidepressant effect will be conducted on related G protein-coupled receptors. Then, diverse derivatives of (+)-paeoveitol will be synthesized and evaluated on revealed target to study structure-activity relationship. The most potential compounds will be further evaluated for anti-depressant efficacy, mechanism, acute toxicity and preliminary pharmacokinetics in vivo，which will provide scientific basis for the discovery of new anti-depressant leading compounds.

抑郁症是严重危害人类健康的精神疾病，目前临床上使用的合成抗抑郁药物取得了显著疗效，但因起效慢、副作用明显等缺点，不能满足治疗需要，亟需研发快速起效、低毒的新型药物。我们前期从疏肝解郁中药川赤芍中发现了新颖骨架的降二萜(±)-paeoveitol；我们首次完成了(+)-和(-)-paeoveitol不对称全合成；采用小鼠强迫游泳实验发现在60 μmol/kg 剂量时(+)-paeoveitol能够显著缩短小鼠强迫游泳的不动时间，其活性与相同剂量阳性药物氟西汀相当，提示其有显著的抗抑郁活性。拟在此基础上，采用精神疾病相关的G-蛋白偶联受体模型揭示其作用靶点;合成结构多样的(+)-paeoveitol类似物，以发现的作用靶点进行衍生物活性研究，探索其构效关系；开展高活性化合物的体内抗抑郁药效评价、对脑内神经递质的影响和作用机制、初步药代、急性毒性等研究，为研发新型抗抑郁先导化合物提供科学依据。

我们前期从疏肝解郁中药川赤芍中发现了新颖骨架的降二萜(±)-paeoveitol并首次完成了(+)-和(-)-paeoveitol不对称全合成；采用小鼠强迫游泳实验发现在60 μmol/kg 剂量时(+)-paeoveitol能够显著缩短小鼠强迫游泳的不动时间，具有潜在抗抑郁活性。项目在此基础上，对paeoveitol开展结构修饰，合成了32个paeoveitol衍生物，利用稳转MT1和MT2受体的体外筛选模型，发现7个化合物对MT1和MT2受体具有激动作用。采用小鼠强迫游泳实验模型对活性最好的化合物开展了体内抗抑郁剂量与效应关系研究，发现高活性化合物2个。发现paeoveitol D在浓度约为1 mM时，对MT1和MT2受体激动率的分别为57.5%和51.7%，在活性指导下合成了paeoveitol D衍生物34个，利用稳转MT1、MT2体外筛选模型发现16个化合物活性较paeoveitol D显著提高，活性化合物显示较好的量效关系。利用Tango assay系统进一步测定了高活性化合物（N-甲基哌嗪衍生物）对MT1和MT2受体的激动活性，结果显示其激动MT1和MT2的EC50分别为21.0和298.9 μM，并能在动物实验中显著缩短小鼠强迫游泳不动时间，可显著升高不同脑区5-羟色胺和多巴胺的含量，且具有良好的量效关系和安全性，是一个潜在的抗抑郁活性候选分子。本项目申请发明专利两项（申请号：202111513524.7. ；202111513606.1.），整理研究论文2篇，其中一篇将于近期投出，将会按照相关要求进行标注。在项目执行期间，负责人博士后出站，并晋升为副研究员，入选中科院“青年创新促进会”，云南省中青年学术和技术带头人后备人才专项，协助培养博士和硕士研究生各1名。