Instituto de Química Médica (IQM-CSIC), 28006 Madrid, Spain.
Alodia Farmacéutica SL, 28108 Alcobendas, Spain.
Int J Mol Sci. 2023 Oct 4;24(19):14894. doi: 10.3390/ijms241914894.
The protein transient receptor potential melastatin type 8 (TRPM8), a non-selective, calcium (Ca)-permeable ion channel is implicated in several pathological conditions, including neuropathic pain states. In our previous research endeavors, we have identified β-lactam derivatives with high hydrophobic character that exhibit potent and selective TRPM8 antagonist activity. This work describes the synthesis of novel derivatives featuring -terminal amides and diversely substituted '-terminal monobenzyl groups in an attempt to increase the total polar surface area (TPSA) in this family of compounds. The primary goal was to assess the influence of these substituents on the inhibition of menthol-induced cellular Ca entry, thereby establishing critical structure-activity relationships. While the substitution of the -butyl ester by isobutyl amide moieties improved the antagonist activity, none of the '-monobencyl derivatives, regardless of the substituent on the phenyl ring, achieved the activity of the model dibenzyl compound. The antagonist potency of the most effective compounds was subsequently verified using Patch-Clamp electrophysiology experiments. Furthermore, we evaluated the selectivity of one of these compounds against other members of the transient receptor potential (TRP) ion channel family and some receptors connected to peripheral pain pathways. This compound demonstrated specificity for TRPM8 channels. To better comprehend the potential mode of interaction, we conducted docking experiments to uncover plausible binding sites on the functionally active tetrameric protein. While the four main populated poses are located by the pore zone, a similar location to that described for the N-(3-aminopropyl)-2-[(3-methylphenyl)methoxy]-N-(2-thienylmethyl)-benzamide (AMTB) antagonist cannot be discarded. Finally, in vivo experiments, involving a couple of selected compounds, revealed significant antinociceptive activity within a mice model of cold allodynia induced by oxaliplatin (OXA).
瞬时受体电位 melastatin 型 8（TRPM8）蛋白是一种非选择性、钙（Ca）渗透性离子通道，与多种病理状态有关，包括神经性疼痛状态。在我们之前的研究中，我们已经鉴定出具有高疏水性的β-内酰胺衍生物，它们表现出有效的和选择性的 TRPM8 拮抗剂活性。这项工作描述了具有末端酰胺和不同取代的'-末端单苄基基团的新型衍生物的合成，试图增加该化合物家族的总极性表面积（TPSA）。主要目标是评估这些取代基对薄荷醇诱导的细胞 Ca 内流抑制的影响，从而建立关键的结构-活性关系。虽然用异丁酰胺取代 -丁基酯提高了拮抗剂的活性，但无论苯环上的取代基如何，'-单苄基衍生物都没有达到模型二苄基化合物的活性。使用 Patch-Clamp 电生理学实验随后验证了最有效化合物的拮抗剂效力。此外，我们评估了其中一种化合物对其他瞬时受体电位（TRP）离子通道家族成员和一些与周围疼痛途径相关的受体的选择性。该化合物显示出对 TRPM8 通道的特异性。为了更好地理解潜在的相互作用模式，我们进行了对接实验，以揭示功能活性四聚体蛋白上可能的结合位点。虽然四个主要的流行构象位于孔区域，但是不能排除类似于 N-(3-氨基丙基）-2-[(3-甲基苯基）甲氧基]-N-(2-噻吩甲基）-苯甲酰胺（AMTB）拮抗剂描述的位置。最后，体内实验涉及几个选定的化合物，在奥沙利铂（OXA）诱导的冷感觉过敏的小鼠模型中显示出显著的镇痛活性。
