Analogs: Unique Probes for Cannabinoid Receptors

描述（由申请人提供）：源自SR 141716 A的化合物（一种有效的delta 9-THC拮抗剂和大麻模拟物）的合成可能导致鉴定出独特的拮抗剂、反向激动剂以及新结构类别的激动剂。这些努力也可以进一步我们的大麻素的结构-活性关系的理解，促进我们的大麻素神经化学系统的理解，并提供相关的药物滥用和脑功能障碍的生化工具和潜在的药物。拟议研究的具体目的是基于我们实验室进行的研究结果，表明可以合成具有独特特征的SR 141716 A类似物：对大麻素受体的高亲和力，并且能够以合理的亲和力完全置换[3 H] CP 55940和[3 H] SR 141716 A，同时能够或不能，取代[3 H] WIN 55212 -2。此外，我们有证据表明，由于这种结合选择性，这些化合物具有独特的药理活性。这些结果表明，可能有必要改变目前大麻素配体-受体相互作用的范式，这可能导致研究和操纵大麻素药理学的创新方法。迄今为止产生的化合物的不同结构似乎适合于三维结构-活性关系分析，其作为以迭代方式进一步设计、合成和测试这类化合物的结构要求的范例。拟用于合成的化合物包括吡唑核各取代基位置的系统性结构修饰，还包括替代吡唑、咪唑和吡唑并[1，5-f]菲啶环系统，其中取代基可能或可能不保持SR 141716 A中的原始空间关系。还提出了来自SR 141716 A的二价配体，我们相信这代表了首次合成二价配体来探测CB 1寡聚化。评价这些类似物的药理学试验将继续包括在人和大鼠脑制备物以及表达CB 1或CB 2受体的转染细胞系中使用[3 H] SR 141716 A、[3 H] CP 55940和[3 H] WIN 55212 -2进行的比较受体结合试验，以确定每种化合物的亲和力和选择性。将对选定的化合物进行使用GTP-γ-[35 S]的公认信号转导试验，以表征其拮抗其他大麻模拟物配体（特别是CP 55940和WIN 55212 -2）的疗效和能力。最感兴趣的类似物也将在分离的组织（小鼠输精管和豚鼠回肠）中以及在小鼠和大鼠体内进行测试，以鉴定具有原位和体内活性的化合物。

DESCRIPTION (provided by applicant): The synthesis of compounds derived from SR141716A, a potent antagonist of delta9-THC and cannabimimetics, may lead to the identification of unique antagonists, inverse agonists, as well as a new structural class of agonists. These efforts can also further our understanding of cannabinoid structure-activity relationships, facilitate our understanding of the cannabinoid neurochemical system and provide biochemical tools and potential medicinal agents relevant to drug abuse and to brain dysfunction. The specific aims of the proposed research are based on results of studies conducted in our laboratory showing that analogs of SR141716A could be synthesized with unique characteristics: high affinity for cannabinoid receptors, and that are able to fully displace [3H]CP55940 and [3H]SR141716A with reasonable affinity, while simultaneously much less able, or unable, to displace [3H]WIN55212-2. In addition, we have evidence to suggest that because of this binding selectivity, these compounds possess a unique profile of pharmacological activity. These results suggest that it might be necessary to change current paradigms of cannabinoid ligand-receptor interaction, and this could lead to innovative approaches to investigating, and manipulating the pharmacology of cannabinoids. The diverse structures of compounds generated to date appear amenable to three dimensional structure-activity relationship analyses, which serves as a paradigm for the further design, synthesis and testing of the structural requirements of this class of compounds in an iterative fashion. Compounds intended for synthesis comprise a systematic structural modification of each substituent position of the pyrazole nucleus and also include alternative pyrazole, imidazoles and pyrazolo [l,5-f] phenanthridine ring systems where the substituents may or may not maintain the original spacial relationships in SR141716A. Bivalent ligands derived from SR141716A are also proposed, and we believe this represents the first synthesis of bivalent ligands to probe for CB1 oligomerization. Pharmacological assays to evaluate these analogs will continue to include a comparative receptor binding assay with [3H]SR141716A, [3H]CP55940 and [3H]WIN55212-2 in human and rat brain preparations and transfected cell lines expressing CB1 or CB2 receptors to establish each compounds affinity and selectivity. An accepted signal transduction assay using GTP-gamma-[35S] will be performed on selected compounds to characterize their efficacy and ability to antagonize other cannabimimetic ligands, particularly CP55940 and WIN55212-2. Analogs of highest interest will also be tested in isolated tissues (mouse vas deferens and guinea pig ileum) and in vivo in the mouse and rat to identify compounds with in situ and in vivo activity.