Phytochemical characterization and antioxidant potential of black mangrove (Avicennia germinans L.) from the northern coast of Ecuador using aqueous and ethanolic extraction

• Identification of bioactive metabolites : A phytochemical characterization was performed that identified the presence of secondary metabolites such as alkaloids, tannins, flavonoids and saponins in the different parts of the black mangrove ( Avicennia germinans ). • Concentration of phenolic compounds: The aqueous extracts of the bark showed a high content of phenolic compounds (629.5 ±10.44 mg GAE g⁻¹), which highlights its potential as a rich source of antioxidants. • High antioxidant activity: The roots demonstrated the highest antioxidant capacity, with 21171.73 µmol Trolox equivalents g⁻¹ in the DPPH assay and 13512.00 µmol Trolox equivalents g⁻¹ in the ABTS assay, significantly surpassing other parts of the plant and many plant species. • Impact on conservation and industrial applications: The findings confirm the potential of A. germinans as a source of bioactive compounds with applications in the pharmaceutical, nutraceutical and environmental sectors, promoting its conservation and sustainable use. Predominant among the mangroves of the northern coast of Ecuador, the black mangrove ( Avicennia germinans) has been traditionally used in medicine. This study focuses on its phytochemical characterization and antioxidant activity. Bark, leaves, seeds, and roots were washed, dried at 35°C for 96 hours until reaching a moisture content of 10 ± 2%, and ground. Extracts were obtained by macerating the plant material (1:10 ratio) with sterile water or 96% ethanol, followed by ultrasound-assisted extraction at 35°C for 1 hour and further maceration at 35 ± 1°C for 24 hours. Qualitative phytochemical screening identified secondary metabolites such as alkaloids, tannins, flavonoids, and saponins, while total phenol content was quantified using the Folin-Ciocalteu method. Antioxidant activity was evaluated using the DPPH and ABTS assays. Aqueous extracts showed higher phenol concentrations, with the bark extract containing 629.5 ±10.44 mg GAE·g⁻¹. The roots exhibited the highest antioxidant activity, with 21171.73 µmol Trolox equivalents g⁻¹ (DPPH) and 13512.00 µmol Trolox equivalents g⁻¹ (ABTS). The antioxidant activity values exhibited statistically significant differences among the extracts and relative to other plant species. The differences in metabolite concentration and antioxidant activity among plant parts and solvents are attributed to physiological adaptation and selective mobility of compounds within the plant. These findings confirm that A. germinans is a valuable source of bioactive compounds with therapeutic and antioxidant properties, supporting its potential use in the development of antioxidant-based formulations. Moreover, these results provide key information for mangrove conservation and its potencial application in pharmaceutical, nutraceutical, and environmental sectors.