Pilot--Molecular features of cembranoids as nicotinic a

烟叶中既含有烟碱激动剂，也含有烟碱型乙酰胆碱受体的各种拮抗剂。最后一类化合物是由环状二萜类化合物组成的，这些二萜类化合物被称为西伯利亚类化合物。初步证据表明，这些化合物可能在大脑中积累到足以显著改变尼古丁作用的浓度。西膜类烟碱拮抗剂 也在海洋无脊椎动物，即柳珊瑚中发现。这些生物体展示了令人惊叹的各种膜衍生物，为结构-活性关系研究提供了一个理想的机会。本建议的目的是：1.确定影响其与电子器官中nAChR亲和力的西膜类分子的分子特征。为此，将通过有机合成的方法制备最丰富的活性海洋西门冬酸甲酯(PAME)的合成类似物，并测试其与电浆膜中受体的特异性结合。2.分离、提纯和鉴定新的以及已知的软珊瑚和烟草衍生的西莫地里类化合物，用于活性测试。3.检测上述化合物对SH-SY5Y和SH-EPL-h-α-4-β-2细胞表达的α3β4和α4β2受体亚型的影响。预期的结果是更好地了解西膜类药物与nAChRs的相互作用，并最终发现神经元受体亚型的特定拮抗剂。这些知识可能最终导致尼古丁成瘾、中风或各种神经退行性疾病的治疗应用。

Tobacco leaves contain both an agonist, nicotine, and various antagonists of nicotinic acetylcholine receptors. The last group is composed of cyclic diterpenoids called cembranoids. Preliminary evidence suggests that these compounds may accumulate in the brain to a concentration sufficient to significantly modify nicotine action. Cembranoid nicotinic antagonists are also found in marine invertebrates, namely gorgonian corals. These organisms display a stunning variety of cembrane derivatives, presenting an ideal opportunity for structure-activity relationship studies. The goals of this proposal are: 1. To determine the molecular features of the cembranoid molecule that affect its affinity for the nAChR from electric organ. For that purpose, synthetic analogues of the most abundant active marine cembranoid, pseudoplexauric acid methyl ester (PAME), will be prepared by organic synthesis and tested for specific binding to the receptor in electroplax membranes. 2. To isolate, purify, and chemically characterize novel as well as previously known soft coral and tobacco-derived cembranoids for activity testing. 3. To test the above compounds on activity of the alpha3beta4 and alpha4beta2 receptor subtypes expressed in SH-SY5Y and SH-EPl-h-alpha-4-beta-2 cell lines, respectively. The expected outcome is a better understanding of cembranoid interaction with nAChRs and eventual finding of specific antagonists for neuronal receptor subtypes. This knowledge might eventually result in therapeutic applications related to nicotine addiction stroke or various neurodegenerative diseases.