Abstract

Alcea rosea L. (Malvaceae) is a medicinal plant traditionally used for treating inflammatory and respiratory disorders, yet its medium-polarity metabolites and associated biological activities remain insufficiently characterised. This study aimed to profile the phytochemical composition of the ethyl acetate fraction of A. rosea, isolate its major coumarin constituent, and evaluate its cytotoxic effects on A549 lung carcinoma cells. High-resolution LC–ESI–QTOF-MS/MS analysis revealed a diverse metabolite profile comprising coumarins, flavonoids, iridoids, phenolic derivatives, and terpenoid esters, with scopoletin identified as a predominant compound. Targeted isolation using preparative TLC yielded 31.2 mg of purified scopoletin, whose identity was confirmed through LC–MS/MS, HPLC retention matching, ¹H NMR spectroscopy, UV–Vis spectral overlap, and FTIR functional group analysis. The ethyl acetate fraction exhibited a clear dose- and time-dependent cytotoxic effect in the MTT assay, with decreasing IC₅₀ values observed over 24, 48, and 72 h of exposure. These findings demonstrate that A. rosea contains a rich diversity of bioactive secondary metabolites and establish scopoletin as a major constituent contributing to its cytotoxic potential. The integrated analytical and biological data presented here provide a foundation for further investigation into the therapeutic relevance of A. rosea and its coumarin derivatives.