Seaweeds are multicellular macroalgae used as potential renewable resource in the field of medical and commmerical environment. The aim of this study was to study the antifungal, phytochemical and repellency activities of the red seaweed G.edulis since published reports on this particular seaweed were limited.The seaweed G.edulis was collected from the Gulf of Mannar coast of Tuticorin in Tamil Nadu. It was shade dried and extracted using five different solvents such as methanol, ethanol, acetone, ethyl acetate and chloroform in a soxhlet apparatus. Among the solvents, the acetone extract showed highest antifungal activity against A.flavus (18±0.4mm) and it was followed by A.terreus (17±0.6mm) and F. semitectum (17±0.6mm). Moderate activity was observed in the ethanol extract showing inhibition zone of (13 ± 0.4mm, 13 ± 0.3mm and 13±0.6mm) against A.niger, Mucor sps and T.viride respectively. In the preliminary phytochemical screening 11 phytoconstituents were present out of the 14 tested.Terpenoids, phenols and flavanoids were present in all the solvent extracts. 100% repellent effects were observed in the acetone extract of 4% concentration of G.edulis during the fourth and fifth hour. At 4% concentration 100% repellency rate was observed with the ethyl acetate and the chloroform extracts at the fifth hour. The present study showed that the seaweed G.edulis may be a rich source of phytoconstituents. Acetone being a polar solvent was effective in extracting bioactive compounds which produced antifungal and repellency activities. The compound producing biological activity could be further isolated and used in the pharmaceutical industry.
