γ-Hydroxybutyric acid (GHB) is a neuroactive substance with specific high-affinity binding sites. To facilitate target identification and ligand optimization, we herein report a comprehensive structure–affinity relationship study for novel ligands targeting these binding sites. A molecular hybridization strategy was used based on the conformationally restricted 3-hydroxycyclopent-1-enecarboxylic acid (HOCPCA) and the linear GHB analog trans-4-hydroxycrotonic acid (T-HCA). In general, all structural modifications performed on HOCPCA led to reduced affinity. In contrast, introduction of diaromatic substituents into the 4-position of T-HCA led to high-affinity analogs (medium nanomolar K_i) for the GHB high-affinity binding sites as the most high-affinity analogs reported to date. The SAR data formed the basis for a three-dimensional pharmacophore model for GHB ligands, which identified molecular features important for high-affinity binding, with high predictive validity. These findings will be valuable in the further processes of both target characterization and ligand identification for the high-affinity GHB binding sites.

中文翻译：

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高效和选择性γ-羟基丁酸（GHB）配体的分子杂交：新型3-羟基环戊-1-烯羧酸（HOCPCA）和反式-γ-羟基巴豆酸（T-HCA）的设计，合成，结合研究和分子建模类似物

γ-羟基丁酸（GHB）是一种具有特定高亲和力结合位点的神经活性物质。为促进目标识别和配体优化，我们在此报告了针对这些结合位点的新型配体的全面结构亲和力关系研究。基于构象受限的3-羟基环戊-1-烯羧酸（HOCPCA）和线性GHB类似物反-4-羟基巴豆酸（T-HCA），使用了分子杂交策略。通常，对HOCPCA进行的所有结构修饰均导致亲和力降低。相反，将二芳族取代基引入T-HCA的4位可产生高亲和力类似物（中等纳摩尔浓度的K _i），作为GHB高亲和力结合位点，是迄今为止报道的最高亲和力类似物。SAR数据构成了GHB配体的三维药效团模型的基础，该模型确定了对高亲和力结合具有重要预测意义的重要分子特征。这些发现在靶标表征和高亲和力GHB结合位点的配体鉴定的进一步过程中将是有价值的。