Diterpines as Selective Kappa Opioid Receptor Agonists

描述(由申请人提供)： 意义：Salvinorin A是一种自然产生的新克拉里达烷二萜类化合物，也是“魔术薄荷”致幻植物丹参的主要活性成分，是一种有效和选择性的k-阿片受体激动剂(Roth等人，Proc Natl Acad Sci USA，2002)。因此，丹参和丹参甲素代表了一类新的滥用药物(Sheffler和Roth，Trends Pharmacol Sci，正在出版中)，它们选择性地针对kappa-阿片受体。地特平是一种选择性多肽受体激动剂的发现是独一无二的，也是史无前例的。因此，阐明丹参甲素作用于k-阿片受体的结构特征将为多肽药物设计提供新的途径。对Salvinorin A与k-阿片受体相互作用的研究也可能提供一个案例研究，为设计具有极高选择性的药物提供一种创新策略。因此，非胺配体，如丹参素A，有可能具有几乎绝对的选择性。为了实现这一总体目标，我们将检验以下两个假设和5个具体目标：假设1：丹参素A以一种独特的方式与k-阿片受体相互作用。具体目标#1：通过定点突变和分子模拟相结合的方法，确定与Salvinorin A结合所必需的k-阿片受体的结构特征。具体目标#2：通过结合定点突变和分子建模方法，确定丹参素A在KOR的激动剂作用所必需的k-阿片受体的结构特征。具体目的#3：比较丹参甲素与部分生物碱激动剂结合和激活KOR的方式。假设2：Salvinorin A的2-甲氧基羰基位置是与k-阿片受体结合和激活所必需的。具体目标#4：比较一系列天然的和合成的2-取代柴胡素A衍生物的结合和功能性质。这些研究可能会澄清萨尔维甲素和相关滥用药物如何在分子和细胞水平上调节它们的作用，并将导致治疗与萨尔维甲素滥用有关的副作用。

DESCRIPTION (provided by applicant): Significance: Salvinorin A, a naturally occurring neoclaridane diterpine and the main active ingredient of the 'magic mint' hallucinogenic plant Salvia divinorum, is a potent and selective k-opioid receptor agonist (Roth et al., Proc Natl Acad Sci USA, 2002). Salvia divinorum and Salvinorin A thus represent a novel class of abused drugs (Sheffler and Roth, Trends Pharmacol Sci, in press) which selectively target the kappa-opioid receptor. The discovery that a diterpine is a selective peptide receptor agonist is unique and unprecedented. Therefore, the elucidation of the structural features responsible for Salvinorin A's actions at k-opioid receptors will illuminate novel approaches for peptide drug design. Investigation of the interaction of Salvinorin A with the k-opioid receptor may also provide a case study representing an innovative strategy for the design of drugs with exceptionally high selectivity. Thus, non-amine ligands, such as salvinorin A, have a potential for nearly absolute selectivity. To accomplish this overall goal we will test the following two hypotheses and 5 specific aims: Hypothesis #1: Salvinorin A interacts with the k-opioid receptor in a unique manner. Specific aim #1: To determine the structural features of the k-opioid receptor essential for binding Salvinorin A via a combination of site-directed mutagenesis and molecular modeling. Specific aim #2: To determine the structural features of the k-opioid receptor essential for the agonist actions of Salvinorin A at the KOR via a combination of site-directed mutagenesis and molecular modeling approaches. Specific aim #3: To compare the mode of binding and activation of the KOR by Salvinorin A with selected alkaloid agonists. Hypothesis #2: The 2-methoxycarbonyl position of Salvinorin A is essential for binding to and activation of the k-opioid receptor. Specific aim #4: To compare the binding and functional properties of a series of naturally occurring and synthetic 2-substituted Saivinorin A derivatives. These studies are likely to clarify how Salvinorin A and related drugs of abuse mediate their actions at the molecular and cellular levels and will lead to treatments for the side-effects related to Salvinorin A abuse.