Design, Synthesis and Pharmacological Evaluation of 4‐Hydroxycoumarin Derivatives as Antiproliferative Agents

Coumarin as an Elite Scaffold in Anti-Breast Cancer Drug Development: Design Strategies, Mechanistic Insights, and Structure-Activity Relationships

Breast cancer is the most common cancer among women. Currently, it poses a significant threat to the healthcare system due to the emerging resistance and toxicity of available drug candidates in clinical practice, thus generating an urgent need for the development of new potent and safer anti-breast cancer drug candidates. Coumarin (chromone-2-one) is an elite ring system widely distributed among natural products and possesses a broad range of pharmacological properties. The unique distribution and pharmacological efficacy of coumarins attract natural product hunters, resulting in the identification of numerous natural coumarins from different natural sources in the last three decades, especially those with anti-breast cancer properties. Inspired by this, numerous synthetic derivatives based on coumarins have been developed by medicinal chemists all around the globe, showing promising anti-breast cancer efficacy. This review is primarily focused on the development of coumarin-inspired anti-breast cancer agents in the last three decades, especially highlighting design strategies, mechanistic insights, and their structure-activity relationship. Natural coumarins having anti-breast cancer efficacy are also briefly highlighted. This review will act as a guideline for researchers and medicinal chemists in designing optimum coumarin-based potent and safer anti-breast cancer agents.

α-Amylase and mycobacterium-TB H37Rv antagonistic efficacy of novel pyrazole-coumarin hybrids: an in vitro and in silico investigation

The present investigation of minutiae to acquire structural information of the novel pyrazole-coumarin hybrids (PC1-PC10) synthesized using ultrasound methods and characterized using different spectroscopic techniques: mass, 1H-NMR, 13 C-NMR and IR spectroscopy, and theoretically explored using the DFT approach with a B3LYP/6-311G (d, p) basis set, and there in vitro, antagonistic efficacy against α-amylase and mycobacterium-TB H37Rv are described in this article. Pyrazole-coumarin hybrids (PC1-PC10) showed α-amylase inhibition ranging from IC50 (0.32-0.58 mM) when compared with acarbose (IC50 = 0.34 mM). Similarly, Mycobacterium-TB H37Rv strain inhibition screening showed MIC values ranging from 62.5 to 1000 µg/mL when compared with rifampicin and isoniazid MIC = 0.25 and 0.20 µg/mL, respectively. Molecular docking and MD simulation studies were performed to determine the active sites and rationalize the activities of the active compounds. To investigate the binding conformation and dynamics responsible for their activity, the three most active compounds (PC1, PC3 and PC6) were docked into the porcine pancreatic α-amylase active site (PDB ID:1OSE), and mycobacterium-TB H37Rv active site (PDB ID: 4TZK). The binding interactions between PC1, PC3, and PC6 with α-amylase were like those responsible for inhibiting α-amylase by acarbose. Also, the mycobacterium-TB H37Rv inhibiting responsible residues were compared with standard isoniazid and rifampicin.Communicated by Ramaswamy H. Sarma.

Design, Synthesis and Cytotoxicity Evaluation of Novel Indole Derivatives of Panaxadiol

Based on the well-known cytotoxicity of indole compounds, we used the 'Fisher indole synthesis' method to introduce appropriately substituted indole rings into panaxadiol (PD), generating eighteen novel Panaxadiol indole derivatives. Six human cancer cell lines (A549, HepG-2, HCT-116, SGC-7901, MDA-MB-231, PC-3 cells) and one normal ovarian cell lines (IOSE144) were designed to evaluate the anti-proliferative activity of the PD derivatives. The results showed that the majority of PD derivatives showed enhanced anti-proliferative activity, when compared with PD, with P-Methylindolo-PD exhibiting the highest cytotoxicity. In A549 cells, IC₅₀ value was 5.01±0.87 μM, which is roughly 12 times higher than the activity of PD and 5 times that of 5-FU. Moreover, cell morphology analysis and Annexin V-FITC/PI assays exhibited that P-Methylindolo-PD could induce A549 cell apoptosis (55.7 % of apoptotic cells at 20 μM). Moreover, molecular docking experiments were performed to explore the molecular mechanism underlining the binding of P-Methylindolo-PD to the active site of EGFR. The results support that P-Methylindolo-PD might be a promising lead compound for further studies.

2-Amino-4-aryl-5-oxo-4,5-dihydropyrano[3,2-c]chromene-3-carbonitriles with microtubule disruptive, centrosome declustering and antiangiogenic effects in vitro and in vivo

A series of fifteen 2‐amino‐4‐aryl‐5‐oxo‐4,5‐dihydropyrano[3,2‐c]chromene‐3‐carbonitriles (1 a–o) were synthesized via a three‐component reaction of 4‐hydroxycoumarin, malononitrile, and diversely substituted benzaldehydes or pyridine carbaldehydes. The compounds were tested for anticancer activities against a panel of eight human tumor cell lines. A few derivatives with high antiproliferative activities and different cancer cell specificity were identified and investigated for their modes of action. They led to microtubule disruption, centrosome de‐clustering and G2/M cell cycle arrest in 518 A2 melanoma cells. They also showed anti‐angiogenic effects in vitro and in vivo.