Minor Uses of Algae and their Products

Abstract

This is a reserve compound found in some quantity in fronds of the Laminariaceae and to a lesser extent in the rockweeds of the Fucaceae. It is a polysaccharide sugar with the general formula (C₅ H₁₀ O₅)_n and was discovered by Schmiedeberg in 1885. Barry (1939) and later Connell, Hirst and Percival (1950) and Percival and Ross (1951) showed that laminaran probably consisted of a branched chain of 20 β-d-glucopyranose units with 1, 3 glucosidic linkages, with the molecule bent in a spiral form. There are also mannitol end groups (2·4–3·7%). Subsequently it has been found that there are two forms, soluble and insoluble. The present situation is that laminaran exists in a reducing and non-reducing form, the latter possessing the mannitol end groups (Percival, 1969; Levring, Hoppe and Schmid, 1969).