ABSTRACT
A series of 30 non-covalent imidazo[1,2-a]quinoxaline-based inhibitors of epidermal growth factor receptor (EGFR) were designed and synthesized. EGFR inhibitory assessment (against wild type) data of compounds revealed 6b, 7h, 7j, 9a and 9c as potent EGFRWT inhibitors with IC50 values of 211.22, 222.21, 193.18, 223.32 and 221.53 nM, respectively, which were comparable to erlotinib (221.03 nM), a positive control. Furthermore, compounds exhibited excellent antiproliferative activity when tested against cancer cell lines harboring EGFRWT; A549, a non-small cell lung cancer (NSCLC), HCT-116 (colon), MDA-MB-231 (breast) and gefitinib-resistant NSCLC cell line H1975 harboring EGFRL858R/T790M. In particular, compound 6b demonstrated significant inhibitory potential against gefitinib-resistant H1975 cells (IC50 = 3.65 µM) as compared to gefitinib (IC50 > 20 µM). Moreover, molecular docking disclosed the binding mode of the 6b to the domain of EGFR (wild type and mutant type), indicating the basis of inhibition. Furthermore, its effects on redox modulation, mitochondrial membrane potential, cell cycle analysis and cell death mode in A549 lung cancer cells were also reported.
Subject(s)
ErbB Receptors/antagonists & inhibitors , Quinoxalines/chemistry , Quinoxalines/pharmacology , A549 Cells , Antineoplastic Agents/pharmacology , Carcinoma, Non-Small-Cell Lung/metabolism , Cell Line, Tumor , Cell Proliferation/drug effects , Drug Resistance, Neoplasm/drug effects , Drug Screening Assays, Antitumor , ErbB Receptors/metabolism , Erlotinib Hydrochloride/pharmacology , Gefitinib/pharmacology , Humans , Imidazoles/chemistry , Imidazoles/pharmacology , Inhibitory Concentration 50 , Lung Neoplasms/metabolism , Molecular Docking Simulation , Mutation/drug effects , Protein Kinase Inhibitors/pharmacology , Structure-Activity RelationshipABSTRACT
Ponicidin, an ent-kaurane diterpenoid derived from Rabdosia rubescens, exhibits antitumor activities against several types of cancers. This review summarizes the botanical sources, biological activities, and biopharmaceutical profile of ponicidin. Additionally, a molecular docking study has been undertaken to correlate the interaction of this diterpenoid with biomacromolecules found in the literature. For this purpose, an up-to-date (till December 2018) literature survey was conducted using a number of databases such as PubMed, Science Direct, Web of Science, Scopus, the American Chemical Society, Clinicaltrials.gov, and Google Scholar. Findings suggest that ponicidin exerts antioxidant and anticancer activity in various test systems, including experimental animals and cultured cancer cells. Research findings revealed that anticancer mechanisms of ponicidin include antioxidant/oxidative stress induction, cytotoxic, apoptotic inductive, chemosensitizer, antiangiogenic, and antiproliferative effects. In silico study suggests that 5ITD (PI3K) was the best protein with which ponicidin interacts to exert its anticancer effect. In conclusion, ponicidin might be a promising plant-derived cancer chemotherapeutic agent.
