Journal of Applied Phycology 8: 155-161, 1996. 155 © 1996 Kluwer Academic Publishers. Printed in Belgium. Annual variation in composition and in vitro anti-HIV-1 activity of the sulfated glucuronogalactan from Schizymenia dubyi (Rhodophyta, Gigartinales) N. Bourgougnonl,*, M. Lahaye 2 , B. Quemener 2 , J-C Chermann 3 , M. Rimbert 4 , M. Cormaci 5 , G. Furnaris & J-M Komprobst 4 1 Laboratoire de Biologie et Biochimie Marines, P6le Sciences et Technologie, Universite de La Rochelle, avenue Marillac, 17042 La Rochelle, France (email: nathalie. bourgougnon @biolo. univ-lr.fr) 2 Laboratoire de Biochimie et Technologie des Glucides, INRA BP 527, 44026 Nantes Cedex 03, France (email: lahaye@nantes. inra.fr) 3 INSERM U322, Campus Universitaire de Luminy BP33, 13273 Marseille, Cedex 09 France 41SOMer, Faculte de Pharmacie, 1 rue Gaston Veil, 44035 Nantes, Cedex 01 France 5 Dipartimento di Botanica, Universita di Catania, Sicily, Italy (*Authorfor correspondence) Received 26 April 1996; revised 22 May 1996; accepted 28 May 1996 Key words: Schizymenia dubyi, sulfated polysaccharide; antiviral; HIV-1 Abstract An account is given of the annual variation in composition and in vitro anti-HIV-1 activity of the water-soluble sulfated glucuronogalactan from Schizymenia dubyi collected in Sicily. No marked variation seasonal chemical or physico-chemical features was observed, with the exception of L-galactose residues and viscosity. Evaluation of the anti-HIV- effect of the polysaccharide indicated that syncitial formation and HIV-associated reverse transcriptase in vitro were completely suppressed at 5 /jg ml-' by alga collected during the summer/spring period. This high anti-HIV- 1 activity corresponded with a decrease in L-galactose, viscosity and sulfate content of the polysaccharide. Introduction Marine algal cell walls contain a large quantity of char- acteristic mucilaginous polysaccharides which have recently been demonstrated to reveal some biologic- al activities (Noda et al., 1989; Given et al., 1990; Indergaard & Ostgaard, 1991; Witvrouw et al., 1994). Red algal cell-walls contain large amounts of sulfated galactans such as agars and carrageenans, gener- ally built on the repeating alternating 1,3-linked /- D-galactopyranose and 1,4-linked anhydro-3,6-L- or D-a-galactopyranose. Different repeating structures have been identified on the basis of the sulfation pat- tern and of the substitution by methoxyl, glycosyl and/or pyruvate groups (Craigie, 1990; Usov, 1992; Knutsen et al., 1994). A sulfated polysaccharide isol- ated from Schizymenia pacifica (Kylin) Kylin (Gigar- tinales, Gymmnophlaeaceae) with chemical character- istics close to that of carrageenans inhibits in vitro Human Immunodeficiency Virus (HIV) replication and reverse transcriptase (Nakashima et al., 1987a, b). The sulfated glucuronogalactan from Schizymenia dubyi (Chauvin ex Duby) J. Agardh collected in Sicily differed from the other generally encountered red algae by its unusually high content of glucuronic acids (Bourgougnon et al., 1993). Indeed, the gametophyt- ic S. dubyi (Sicily) was shown to contain a sulfated polysaccharide composed of 1/0.75/1.3 of galactose, glucuronic acid and sulfate groups. 45% of total galactose was in a L-form and no 3,6-anhydrogalactose was detected (Bourgougnon et al., 1996a). This polysaccharide marked in vitro specific activity against several viruses, including HIV-1 (Bourgougnon et al., 1993; 1996b). The present work relates to the seasonal variation of its chemical com- position and its relationship to the in vitro anti-HIV activity of S. dubyi sulfated glucuronogalactan.