目的:5-HT受体(5-HTR)亚型5-HT2A和5-HT2C是重要的神经治疗靶点,虽然,获得对5-HT2B和密切相关的组胺H1Rs的选择性是具有挑战性的。这里,我们描述了新型4-苯基-2-二甲基氨基四氢嘧啶(4-PAT)与5-HT2A和5-HT2CR的选择性结合的分子决定簇。
方法:我们合成了42种在C(4)-苯基间位具有卤素或芳基部分的新型4-PAT。亲和力,函数,分子建模,进行了5-HT2AR诱变研究,以了解5-HT2型和H1R的结构-活性关系。铅4-PAT型选择性5-HT2A/5-HT2CR反向激动剂与匹马色林进行了比较,一种被批准用于治疗精神病的选择性5-HT2A/5-HT2CR反向激动剂,在鼠标头部抽搐的反应中,和运动活动分析,作为抗精神病药物开发相关的模型。
结果:(2S,4R)-构型非选择性地与5-HT2A结合,5-HT2C,和H1Rs,超过5-HT2BRs的选择性>100倍,然而,(2R,4R)-构型比5-HT2C优先结合5-HT2A,比5-HT2B和H1R具有>100倍的选择性。结果表明,5-HT2ARs中的G2385.42和V2355.39(在5-HT2CRs中保守)对于高亲和力结合很重要,然而,与T1945.42和W1584.56的相互作用决定了H1R亲和力。4-PAT(2S,4R)-2k,一种有效和选择性的5-HT2A/5-HT2CR反向激动剂,在小鼠头部抽搐反应试验中具有比马色林的活性,但在不抑制运动活动方面是不同的。
结论:我们提供了新的4-PAT化学型可以通过优化跨膜结构域5中的配体-受体相互作用产生选择性的5-HT2A/5-HT2C-R反向激动剂,用于抗精神病药物开发。我们还表明,可以利用手性获得对H1Rs的选择性,这可能会避免镇静作用。
OBJECTIVE: The 5-HT receptor (5-HTR) subtypes 5-HT2A and 5-HT2C are important neurotherapeutic targets, though, obtaining selectivity over 5-HT2B and closely related histamine
H1 Rs is challenging. Here, we delineated molecular determinants of selective binding to 5-HT2A and 5-HT2C Rs for novel 4-phenyl-2-dimethylaminotetralins (4-PATs).
METHODS: We synthesized 42 novel 4-PATs with halogen or aryl moieties at the C(4)-phenyl meta position. Affinity, function, molecular modeling, and 5-HT2A R mutagenesis studies were undertaken to understand structure-activity relationships at 5-HT2 -type and
H1 Rs. Lead 4-PAT-type selective 5-HT2A /5-HT2C R inverse agonists were compared to pimavanserin, a selective 5-HT2A /5-HT2C R inverse agonist approved to treat psychoses, in the mouse head twitch response, and locomotor activity assays, as models relevant to antipsychotic drug development.
RESULTS: Most 4-PAT diastereomers in the (2S,4R)-configuration bound non-selectively to 5-HT2A , 5-HT2C, and
H1 Rs, with >100-fold selectivity over 5-HT2B Rs, whereas, diastereomers in the (2R,4R)-configuration bound preferentially to 5-HT2A over 5-HT2C Rs and had >100-fold selectivity over 5-HT2B and
H1 Rs. Results suggest that G2385.42 and V2355.39 in 5-HT2A Rs (conserved in 5-HT2C Rs) are important for high affinity binding, whereas, interactions with T1945.42 and W1584.56 determine
H1 R affinity. The 4-PAT (2S,4R)-2k, a potent and selective 5-HT2A /5-HT2C R inverse agonist, had activity like pimavanserin in the mouse head-twitch response assay, but was distinct in not suppressing locomotor activity.
CONCLUSIONS: We provide evidence that the novel 4-PAT chemotype can yield selective 5-HT2A /5-HT2C R inverse agonists for antipsychotic drug development by optimizing ligand-receptor interactions in transmembrane domain 5. We also show that chirality can be exploited to attain selectivity over H1 Rs which may circumvent sedative effects.