Comparative Phytochemical and Pharmacological Properties of Commonly Available Tropical Green Seaweeds

This study analyzed the ethyl acetate-methanol extracts of tropical green seaweeds for phytochemical indicators and antioxidant activities. Compositional analysis of the organic extracts of green seaweeds Ulva lactuca (formerly Ulva fasciata), Halimeda macroloba, Chaetomorpha linum and Chaetomorpha antennina identified the presence of phytoconstituents, such as total phenols, terpenoids, saponins and flavanoids. U. lactuca exhibited higher levels of total phenols (59.8 mg GAE/g), saponins (1.77 %), flavanoids (2.3 %), as well as greater 2, 2-diphenyl-1-picrylhydrazylradical radical quenching activity (DPPH.IC50 0.86 mg/mL). Extracts of U. lactuca and H. macrobola showed promising antimicrobial activities against Vibrio parahaemolyticus. Proton nuclear magnetic resonance fingerprint analyses of the solvent extracts showed that higher proton integrals were present in the downfield regions in U. lactuca, which could be responsible for lowering DPPH activity. The present work supports that the renewable green seaweed U. lactuca could be used to isolate prospective bioactive leads