1H NMR Analysis and Bioautography Screening of Methanol Extract of Sargassum wightii by Chromatographic Separation

Seaweeds are an important source of bioactive secondary metabolites which may be employed as potential leads in the development of new pharmaceutical agents. In the present study, the methanolic extract of S. wightii has been screened for bioactive compounds. The biochemical analysis revealed that the alga is rich in carbohydrates (75.47μg/mg) and proteins (43.8μg/mg). Phytochemical screening revealed the presence of alkaloids, saponins, flavonoids, quinines, phenols and phlobatannins. The total phenolic and total flavonoid contents were 2.71 and 2.65 μg/ml respectively, which were confirmed by TLC and were further purified by silica gel column chromatography. The Bioautography screening of the fractions was performed by the agar well diffusion assay and H₂O₂ scavenging activity. Two fractions that showed potential antioxidant (95.81% and 94.28%) and antibacterial activity were further characterized by FT-IR and NMR spectroscopy which revealed the presence of Myricetin and Quercetin.