Abstract: Objective: To screen and characterize the bioactive compounds in the brown seaweed Turbinaria ornata. Methods: The brown seaweed, T. ornata was collected from Nalupanai coast of Gulf of Mannar. It was cleaned from epiphytes, washed, shade dried and powdered. Algal extraction was carried out using distilled water, ethanol, methanol, acetone and petroleum ether. The crude methanolic extract was subjected to GC-MS analysis to reveal the phyco-constituents. Results: The results obtained in the phytochemical screening supports that the seaweeds contain biologically active substance. Methanol was identified as the most appropriate solvent to extract the bioactive compounds. Different fatty acids and volatile compounds were identified in the GC-MS analysis. The volatile mixture comprised of hydrocarbons, acids, aldehydes, ketones, esters, ethers, alcohols, halogenated and aromatic compounds.

Keywords: Turbinaria ornata, phycochemical screening, bioactive compounds, GC-MS.