Phytochemical Constituents, Antimicrobial Properties and Bioactivity of Marine Red Seaweed () and Seagrass ().

The present work was performed to evaluate the levels of phytochemical constituents and the antioxidant and antibacterial properties of marine red seaweed () and seagrass (). Quantitative phytochemical analysis, antioxidant activity and antimicrobial activity against five potential pathogenic bacteria was investigated. In each case, we found the presence of flavonoids, tannins, phenolic compounds, glycosides, steroids, carbohydrates and ashes. Alkaloids were only found in , though they were not found in . The antimicrobial properties of both and chloroform extracts were found to be antagonistically effective against the Gram-positive bacteria and the Gram-negative bacteria , and . GC-MS analysis revealed the presence of 94 bioactive compounds in and 104 bioactive compounds in , including phenol, decane, dodecane, hexadecane, vanillin, heptadecane, diphenylamine, benzophenone, octadecanoic acid, dotriaconate, benzene, phytol, butanoic acid and 2-hydroxyl-ethyl ether, which all played important roles in antioxidant and antibacterial activities. Thus, in view of the results, both and could be considered to be sources of ingredients with appreciable nutritional and medicinal value.