Evaluation of antioxidant and antibacterial activities of some selected seaweeds from Saint Martin's Island of Bangladesh

The effects of extracting solvents on the antioxidant and antibacterial activity of crude extracts of six seaweeds were investigated. The antioxidant activity of seaweed crude extracts was evaluated by total antioxidant activity (TAA), 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)diammonium salt (ABTS), and cupric reducing antioxidant capacity (CUPRAC) assays. Acetone extract of B. wrightii showed significantly (P < 0.05) the highest total phenolic content (TPC) (71.09 mg GAE/g), while methanolic extract of Porphyra sp. had the highest total flavonoid content (75.61 mg QE/g). Methanolic extract of S. muticum showed significantly (P < 0.05) the highest TAA. Methanolic extract of P. tetrastromatica and S. muticum showed significantly (P < 0.05) the highest DPPH and ABTS radical scavenging effects, while acetone extract of B. wrightii…