Abstract

The Tabebuia aurea (Bignoniaceae) is recognized as a plant with significant ethnomedicinal potential. Species within the Tabebuia sp. have long been utilized in traditional medicine for the treatment of various conditions, including infectious diseases, inflammatory disorders, and metabolic syndromes. This study reports the isolation, screening of naphthoquinone content, and cytotoxic evaluation of three lapachol derivatives, lapachol (1), α-lapachone (2), and β-lapachone (3), from the bark of T. aurea. The bark extracts yielded the highest concentrations of these naphthoquinones, with acetone providing the greatest retrieval by 36.62 ± 2.44 ppm. Among the isolates, β-lapachone demonstrated the strongest cytotoxic activity against HeLa, MCF-7, and A549 cell lines with IC50 values of 6.24 ± 0.52, 2.85 ± 0.26, and 5.61 ± 0.88 μM, respectively. Solvent polarity and tissue type markedly influenced metabolite distribution, identifying bark–acetone as the optimal source of bioactive naphthoquinones. The results provide insight into the therapeutic potential of T. aurea and contribute to the upward evidence supporting its dual role in biodiversity restoration and herbal medicine development.

Key words: T. aurea, lapachol derivatives, cytotoxic activity, human cancer cells