Structural Studies

Polysaccharide and Lipid Composition of the Brown Seaweed Laminaria gurjanovae

N. M. Shevchenko1, S. D. Anastyuk1, N. I. Gerasimenko1, P. S. Dmitrenok1, V. V. Isakov1 and T. N. Zvyagintseva1#

#Phone: (4232) 31-07-05; fax: (4232) 31-40-50; e-mail: zvyag@piboc.dvo.ru

1Pacific Institute of Bioorganic Chemistry, Far-East Division, Russian Academy of Sciences, Vladivostok, pr. 100 Let Vladivostoku 159, 690022, Russia

Received: April 7, 2006;  in final form: August 1, 2006

Abstract. Polysaccharide and lipid composition of the Pacific brown seaweed Laminaria gurjanovae is determined. Alginic acid is shown to be the main polysaccharide of its biomass (about 28%); it consists of mannuronic and guluronic acid residues at a ratio of 3:1. The yield of water-soluble polymannuronic acid is low and does not exceed 1.1% of dry biomass. High laminaran content (about 22%) is found, whereas the yield of fucoidan is no more than 3.6%. Laminaran consists of two fractions, soluble and insoluble in cold water, their ratio is 2.5:1. Insoluble laminaran is a practically linear 1,3-β-D-glucan, and the soluble fraction was shown to be 1,3;1,6-β-D-glucan. The oligosaccharide products of desulfation or partial acidic hydrolysis of fucoidan were studied by MALDI TOF MS; they were found to be fuco- and galactooligosaccharides. The fucoidan is suggested to be a highly sulfated partially acetylated galactofucan (Fuc/Gal is ~1:1). The main lipid components of the dried L. gurjanovae are neutral lipids and glyceroglycolipids, whereas phospholipids are found in minor amounts. The main fatty acid components of lipids are 14:0, 16:0, 16:1 ω-7, 18:1 ω-7 and 18:2 ω-6 acids.

Key words: alginate, brown seaweed, fatty acids, fucoidanglyceroglycolipidlaminaranLaminaria gurjanovaephospholipid

Russian Journal of Bioorganic Chemistry 2007, 33 (1): 88-98