Chellamanimegalai, P.; Deshmukhe, G.; Balange, A.K., and Layana, P., 2024. Effect of solvents on extraction efficiency and in vitro antioxidant activity of bioactive compounds from Dictyota ceylanica and Dictyota cervicornis. Journal of Coastal Research, 40(5), 929–936. Charlotte (North Carolina), ISSN 0749-0208.

Seaweeds can fight reactive oxygen species by producing secondary metabolites in adverse environmental conditions. In the present study, bioactive compounds, including chlorophyll a and c₁ + c₂, carotenoids, fucoxanthin, and total phenols, were extracted from Dictyota ceylanica and Dictyota cervicornis using various solvents to evaluate their in vitro antioxidant activities. Species-specific and solvent-specific differences (p < 0.05) were observed for those compounds. D. ceylanica yielded high chlorophyll a (2.083 mg/g) and carotenoids (0.672 mg/g) in acetone, whereas D. cervicornis showed a maximum of chlorophyll c₁ + c₂ (1.134 mg/g) and fucoxanthin (0.803 mg/g) in dimethyl sulfoxide. D. cervicornis was found to have a significant amount of total phenols (583.46 mg GAE/100 g), DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging activity (39.85%), ferric reducing antioxidant power activity (472.81 mg TE/100 g), and total antioxidant activity (1037.52 mg AAE/100 g) in the water extract. The Pearson's correlation and R² value revealed that chlorophyll a, chlorophyll c₁ + c₂, carotenoids, fucoxanthin, and total phenols are highly responsible for the remarkable antioxidant activities in D. ceylanica and D. cervicornis.