4-Chloro-4-Methoxychalcone and its analogues as a Potential Anticancer Agent in Breast Cancer: A Review

Abstract

Breast cancer remains the most commonly diagnosed cancer among women worldwide and continues to present significant therapeutic challenges, particularly in aggressive subtypes such as triple-negative breast cancer (TNBC), where effective targeted therapies are limited. Chalcones, a class of α,β-unsaturated carbonyl compounds, have emerged as promising anticancer scaffolds because of their structural simplicity, synthetic accessibility, and diverse biological activities. Among them, 4-chloro-4′-methoxychalcone has attracted considerable interest due to its unique electronic architecture, generated by the combination of an electron-withdrawing para-chloro group and an electron-donating para-methoxy group, which enhances molecular polarization and target-binding potential. This review summarizes current evidence regarding the pharmacological activity, molecular targets, and structure–activity relationships (SARs) of 4-chloro-4′-methoxychalcone and related chloro-methoxy chalcone analogues in breast cancer. Available studies indicate that these compounds exert anticancer effects through multiple mechanisms, including modulation of estrogen receptor-α (ERα), HER2/EGFR tyrosine kinases, Bcl-2/BAX-mediated apoptosis, cyclin B1/CDK1 cell-cycle regulation, β-tubulin polymerization, VEGF/VEGFR-2 signaling, NF-κB, histone deacetylases, and MAPK/PI3K/AKT pathways. SAR analyses consistently identify the para-chloro/para-methoxy substitution pattern as favorable for enhanced anticancer activity, while molecular docking studies support strong interactions with several oncogenic targets. Related analogues have demonstrated low micromolar cytotoxicity against breast cancer cell lines, including MCF-7 and MDA-MB-231. Despite these promising findings, major translational gaps remain, including limited in vivo validation, insufficient ADMET characterization, and the absence of clinical studies. Overall, 4-chloro-4′-methoxychalcone represents a promising multi-target lead scaffold for future breast cancer drug development.