International Journal of Biology Reports

en Comparative evaluation of phytochemical contents and antioxidant activity of three marine macroalgal taxa from the Gulf of Mannar, Sri Lanka عمومى General پژوهشي Research Marine macroalgae are recognized as promising sources of bioactive compounds with potential applications in functional foods and pharmaceutical research. This study investigated and compared the phytochemical contents and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activities of three marine macroalgal taxa, Sargassum sp., Ulva sp. and Codium sp., collected from the intertidal zone of the Gulf of Mannar, Sri Lanka, during the 2024 monsoon season. Methanolic extracts were evaluated for total phenolic content (TPC) and total flavonoid content (TFC), while polysaccharide content was also determined. Significant differences in phytochemical contents and antioxidant activity were observed among the three taxa (p < 0.001). Sargassum sp. exhibited the highest TPC (42.6 ± 2.3 mg gallic acid equivalents g⁻¹ dry weight) and TFC (18.2 ± 1.4 mg quercetin equivalents g⁻¹ dry weight), followed by Ulva sp. (28.4 ± 1.8 and 12.6 ± 0.9 mg g⁻¹, respectively) and Codium sp. (19.7 ± 1.5 and 8.4 ± 0.7 mg g⁻¹, respectively). Polysaccharide contents ranged from 145 ± 10 to 185 ± 12 mg g⁻¹ dry weight. In the DPPH radical-scavenging assay, Sargassum sp. showed the strongest antioxidant activity, with the lowest IC₅₀ value (0.38 ± 0.05 mg mL⁻¹), followed by Ulva sp. (0.52 ± 0.06 mg mL⁻¹) and Codium sp. (0.71 ± 0.07 mg mL⁻¹). Correlation analysis indicated a strong association between phenolic content and antioxidant activity (r = 0.92, p < 0.001). Overall, the findings identify Sargassum sp. as the most promising of the three investigated macroalgal taxa in terms of phenolic content and DPPH radical-scavenging activity. Further chemical characterization, biological validation and toxicity assessment are required to establish their potential applications in functional foods and pharmaceutical products. Antioxidant activity, Codium, DPPH assay, marine macroalgae, phenolic compounds, polysaccharides, Sri Lanka, Sargassum, Ulva 0 0 http://injbir.com/browse.php?a_code=A-10-60-2&slc_lang=en&sid=1 Chathura Kavinda chathuocean98728@gmail.com No Ocean University Of Sri Lanka Gihani Chathurangi chathurangi246@gmail.com No Colombo University Of Sri Lanka Sapunika Sammandapperum nsapunika@gmail.com No Ocean University Of Sri Lanka Anukshi Madurangi madurangirajapaksha2016@gmail.com No Ocean University Of Sri Lanka Randi Hansima randinihansima24@gmail.com No Ocean University Of Sri Lanka Sajeewani Jayapala SajeewanieJ@ocu.ac.lk No Ocean University Of Sri Lanka Rochana Weerasinghe rochanaweerasingha@gmail.com No NARA Lanka Wickramasingha LankaW@ocu.ac.lk Yes Ocean University Of Sri Lanka