Synthesis and anti-cancer screening of benzopyran derivatives

Introduction: Global cancer incidence continues to rise, with an estimated 20 million new cases and 10 million deaths reported in 2025. Despite significant advances in early detection and therapeutic strategies, cancer remains one of the leading causes of mortality worldwide. Current research efforts are directed toward the discovery and development of novel compounds that offer enhanced anticancer efficacy with minimal side effects. Objectives of the Study: This study aims to synthesize and characterize a series of novel 2-(toluene sulfonamido)-3-cyano-7,7-dimethyl-4-substituted phenyl-5,6,7,8-tetrahydrobenzopyran-5-one derivatives and evaluate their anticancer potential against MCF-7 breast cancer cells. Cytotoxic activity is assessed using the MTT assay to determine IC₅₀ values, with the objective of identifying a potent lead compound for the development of an effective breast cancer therapy. Experimental Procedure: Substituted benzaldehyde and malononitrile were condensed in ethanol using sodium hydroxide to afford the arylidene-malononitrile intermediate which was subsequently refluxed with dimedone to yield the cyclized benzopyran compound, which was then treated with aryl sulfonyl chloride in the presence of triethylamine to furnish the final benzopyran derivatives. The reaction sequence proceeds through a Knoevenagel condensation followed by a Michael addition mechanism. Spectroscopic Characterization: The synthesized compounds (THBP2 to THBP8) were characterized by melting point, UV, IR, ¹H NMR, and mass spectrometry. The spectral data obtained were in good agreement with the proposed molecular structures, confirming the successful synthesis and purity of the target compounds. MTT assay in MCF-7 cell line The cytotoxic activity of THBP2 to THBP8 was evaluated against MCF-7 breast cancer cells using the MTT assay at concentrations ranging from 6.25-100 µg/ml. Cell viability was determined from the reduction of MTT to formazan, and IC₅₀ values were calculated from the dose response curves. Research Outcome: A series of benzopyran derivatives were successfully synthesized and characterized using spectroscopic techniques. The MTT assay results demonstrated that THBP-6 exhibited the highest cytotoxic activity, with an IC₅₀ value of 20.99 µg/mL, highlighting its potential as a promising anticancer lead compound. THBP6 exhibits low IC₅₀ despite containing electron-donating groups, likely due to enhanced lipophilicity and optimal electronic or steric factors that promote stronger binding to the target in MCF-7 cells. Conclusion: Five novel benzopyran derivatives were synthesized and screened for anticancer activity against MCF-7 cells. In future perspectives, the potent activity of THBP-6 suggests that sulphonamide and cyano substituted benzopyran scaffolds could be further optimized and explored as promising candidates for anticancer drug development.