Piperlongumine is a natural amide alkaloid isolated from several species of Piper and is described in the literature as selectively cytotoxic to several cancer cell lines. Inhibiting cell migration has gained considerable interest as an approach for discovering antimetastatic agents because this process is fundamental to metastasis. Piperlongumine, selected from cell-based assay screening of NuBBE Database, inhibited the migration of MDA-MB-231 breast cancer cells with an EC 50 of 3.0 ± 1.0 µM by the Boyden chamber assay. A series of five analogous compounds based on the structure of piperlongumine were designed, synthesized and evaluated in cell migration and cytotoxicity assays. The analogue designed by molecular simplification ((E)-N-acryloyl-3-(3,4,5-trimethoxyphenyl)acrylamide) was the most active of the series, with an EC 50 of 1.5 ± 1 µM. Additionally, this compound was selectively cytotoxic, with a selectivity index (SI) of 4.4.
Keywords: piperlongumine, piplartine, piperamide, cytotoxicity, cell migration inhibition
IntroductionMetastasis is the process by which undifferentiated cancer cells migrate to other parts of the body.1,2 Suppression of metastasis is an urgent need in cancer treatment, as most existing drugs only inhibit cell proliferation.3 Traditionally, chemotherapy is based on cytotoxic therapeutic agents that inhibit proliferation and cause cell death. However, the strategy of inhibiting cell migration has recently gained considerable interest. 4 Several compounds that inhibit the process of metastasis have been described to date. 5,6 Paclitaxel, which was originally discovered as an antimitotic agent that disrupts the cell cycle in cancer cells by stabilizing microtubules, exhibits marked and selective inhibition of tumor cell migration.
7As extensively reviewed elsewhere, biodiversity in nature has provided unique chemical scaffolds that have been used as templates for medicinal chemistry and drug discovery. [8][9][10][11][12][13] The availability of natural compound libraries is of significant importance for integrating natural products and medicinal chemistry, especially for the identification of new bioactive agents and the rational design of compounds in drug discovery.14 Within this context, we selected the natural product piperlongumine (1), also known as piplartine, from cell-based assay screening of NuBBE Database (NuBBE DB ) 15 and evaluated its ability to inhibit Synthetic Analogue of the Natural Product Piperlongumine as a Potent Inhibitor of Breast Cancer Cell Line Migration J. Braz. Chem. Soc. 476 cancer cell migration using biological and target-based experiments.Piperlongumine (1, Figure 1) is an alkamide isolated from several species of Piper (Piperaceae). 16 It is described as possessing antifungal properties, 17 cytotoxicity toward several cancer cell lines, 18,19 and trypanocidal effects, 20 as well as other biological activities. 21 Furthermore, piperlongumine selectively induces cell death in cancer cells but does not reduce viability in normal cells.
22This ...