Table1_Synthesis, structure-activity relationships and biological evaluation of benzimidazole derived sulfonylurea analogues as a new class of antagonists of P2Y1 receptor.docx

The P2Y receptors are responsible for the regulation of various physiological processes including neurotransmission and inflammatory responses. These receptors are also considered as novel potential therapeutic targets for prevention and treatment of thrombosis, neurological disorders, pain, cardiac diseases and cancer. Previously, number of P2Y receptor antagonists has been investigated but they are less potent and non-selective with poor solubility profile. Herein, we present the synthesis of new class of benzimidazole derived sulfonylureas (1a-y) as potent antagonists of P2Y receptors, with the specific aim to explore selective antagonists of P2Y1 receptors. The efficacy and selectivity of the synthesized derivatives 1) against four P2Y receptors i.e., t-P2Y1, h-P2Y2, h-P2Y4, and r-P2Y6Rs was carried out by calcium mobilization assay. The results revealed that except 1b, 1d, 1l, 1m, 1o, 1u, 1v, 1w, and 1y, rest of the synthesized derivatives exhibited moderate to excellent inhibitory potential against P2Y1 receptors. Among the potent antagonists, derivative 1h depicted the maximum inhibition of P2Y1 receptor in calcium signalling assay, with an IC50 value of 0.19 ± 0.04 µM. The potential of inhibition was validated by computational investigations where bonding and non-bonding interactions between ligand and targeted receptor further strengthen the study. The best identified derivative 1h revealed the same binding mechanism as that of already reported selective antagonist of P2Y1 receptor i.e (1-(2- (2-tert-butyl-phenoxy) pyridin-3-yl)-3–4-(trifluoromethoxy) phenylurea but the newly synthesized derivative exhibited better solubility profile. Hence, this derivative can be used as lead candidate for the synthesis of more potential antagonist with much better solubility profile and medicinal importance.

P2Y受体（P2Y receptors）可调控包括神经传递、炎症反应在内的多种生理过程。该类受体同时被视为血栓形成、神经系统疾病、疼痛、心脏疾病及癌症的预防与治疗的新型潜在治疗靶点。此前已有多款P2Y受体拮抗剂被研究，但此类拮抗剂普遍存在药效偏弱、选择性不佳且溶解度欠佳的问题。本文报道了一类全新的苯并咪唑衍生磺酰脲类（benzimidazole derived sulfonylureas）化合物（1a~1y）作为强效P2Y受体拮抗剂的合成工作，核心目标为筛选P2Y1受体（P2Y1 receptors）的选择性拮抗剂。我们通过钙动员实验（calcium mobilization assay）评估了上述合成衍生物对四种P2Y受体——即t-P2Y1、h-P2Y2、h-P2Y4及r-P2Y6受体——的活性与选择性。结果显示，除1b、1d、1l、1m、1o、1u、1v、1w及1y外，其余合成衍生物对P2Y1受体均表现出中等至优异的抑制活性。在强效拮抗剂中，化合物1h在钙信号检测实验中展现出对P2Y1受体最强的抑制作用，其半数抑制浓度（IC50）为0.19 ± 0.04 µM。该抑制活性通过计算模拟研究得到验证，配体与靶标受体间的成键及非键相互作用进一步支撑了本研究的结论。经筛选得到的最优化合物1h，与已报道的P2Y1受体选择性拮抗剂——1-(2-(2-叔丁基苯氧基)吡啶-3-基)-3-(4-(三氟甲氧基)苯基)脲——具有相同的结合机制，但本研究中新合成的衍生物展现出更优异的溶解度特性。因此，该化合物可作为先导候选物，用于开发活性更强、溶解度更佳且具备药用价值的更高效P2Y1受体拮抗剂。