Human proteinase‐activated receptor 2 (PAR2), a transmembrane G‐protein‐coupled receptor (GPCR), is an attractive target for a novel anticancer therapy, as it plays a critical role in cell migration and invasion. Selective PAR2 inhibitors therefore have potential as anti‐metastatic drugs. Knowing that the natural product teleocidin A2 is able to inhibit PAR2 in tumor cells, the goal of the present study was to elaborate structure–activity relationships and to identify potent PAR2 inhibitors with lower activity against the adverse target, protein kinase C (PKC). For this purpose, an efficient gram‐scale total synthesis of indolactam V (i.e., the parent structure of all teleocidins) was developed, and a library of derivatives was prepared. Some compounds were indeed found to exhibit high potency as PAR2 inhibitors at low nanomolar concentrations with improved selectivity (relative to teleocidin A2). The pseudopeptidic fragment bridging the C3 and C4 positions of the indole core proved to be essential for target binding, whereas activity and target selectivity depends on the substituents at N1 or C7. This study revealed novel derivatives that show high efficacy in PAR2 antagonism combined with increased selectivity.

中文翻译：

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合成吲哚内酰胺V类似物作为三阴性乳腺癌细胞中PAR2诱导的钙动员的抑制剂。

人蛋白酶激活受体2（PAR2）是一种跨膜G蛋白偶联受体（GPCR），是新型抗癌治疗的引人注目的靶标，因为它在细胞迁移和侵袭中起着至关重要的作用。因此，选择性PAR2抑制剂具有作为抗转移药物的潜力。知道天然产物telociocidin A2能够抑制肿瘤细胞中的PAR2，因此本研究的目的是阐明结构与活性之间的关系，并确定对有害靶标蛋白激酶C（PKC）具有较低活性的有效PAR2抑制剂。为了这个目的，开发了吲哚内酰胺V的有效的克级全合成（即，所有teleocidins的母体结构），并制备了衍生物库。实际上，发现某些化合物在低纳摩尔浓度下具有较高的选择性（相对于Teleocidin A2）作为PAR2抑制剂。桥联吲哚核的C3和C4位置的伪肽片段被证明对靶标结合至关重要，而活性和靶标选择性则取决于N1或C7处的取代基。这项研究揭示了新型衍生物，在PAR2拮抗作用中表现出很高的功效，并具有更高的选择性。