Seasonal Variation in Alginic Acid, Mannitol, Laminarin and Fucoidin in the Brown Alga, Ecklonia radiata

THE brown alga Ecklonia radiata (Ag.) J. Ag. which occurs abundantly in the sub-littoral zo ne of the southern coasts of Australia, has been found to contain alginic acid, mannitol, laminarin and fucoidin, in conformity with observations on other species of the Laminariales from South Africa and the northern hemisphere. The above constituents were isolated from the seaweed and characterized by physical constants, chromatography and infra-red spectra 1 . An examination has now been made of the seasonal variation in the content of these carbohydrates, which is of interest in connexion with their biochemical function and possible utilization.