Evaluation of cytotoxicity and radical scavenging activities of flavones isolated from the twigs of Dodonaea angustifolia

Dodonaea angustifolia (commonly known as Kitikita in Amharic) is a medicinal plant widely used in traditional medicine for its diverse therapeutic properties. The twigs of the plant were extracted with 1:1 (methanol:dichloromethane mixture) and subjected to chromatographic techniques and yielded 8 pure compounds included: 5,7-dihydro-3,4′,6-trimethoxyflavone 1, 5,6,7-trihydroxy-3,4'-dimethoxyflavone 2, 5,7,4'-trihydroxy-3,6-dimethoxyflavone 3, 5-hydroxy-3,4",6,7-tetramethoxyflavone 4, 5,4'-dihydroxy-3,6,7-trimethoxyflavone 5, 5,7,8,4’-tetra hydroxy-3,6-dimethoxy flavone 6, l-C-syringylglycerol 7, and fraxetin 8. Their structural elucidation was performed using spectroscopic data (1D and 2D NMR) in combination with the literature values. The antibacterial, cytotoxic, and antioxidant activities of these isolated pure compounds were evaluated. Antibacterial assays, conducted against both Gram-positive and Gram-negative bacteria, revealed that the compounds exhibited no activity compared to standard antibiotics. In cytotoxicity tests using the KB-3-1 human cervix carcinoma cell line, the compounds 1, 3 and 5 showed moderate activity, with lower cytotoxicity relative to Cryptophycin 52. The antioxidant capacity, assessed using the DPPH radical scavenging assay, and compounds 1 and 3 indicated weak free radical scavenging potential. These findings highlight the chemical diversity of Dodonaea angustifolia twigs and their potential as sources of bioactive compounds for medicinal applications. KEY WORDS: Dodonaea angustifolia, Structural elucidation, Cytotoxicity test, Antibacterial activity, Antioxidant activity Bull. Chem. Soc. Ethiop. 2025, 39(6), 1177-1184. DOI: https://dx.doi.org/10.4314/bcse.v39i6.12