Description
Carrageenans are mucopolysaccharides from the cell walls of the red algae. They are anionic linear polymers composed of 1,3α-1,4β-galactans having one (κ-), two (ι-) or three (λ-) sulfates per disaccharide unit. In ionic solutions, κ- and ι-carrageenans self-associate into helical structures that form rigid or flexible gels, respectively. λ-carrageenans do not form helices and are non-gelling. Carrageenans are used commercially as thickeners and stabilizing agents.Carrageenans are used to suppress immune response in vivo and in vitro via mechanisms believed to involve selective cytopathic effect on macrophages. As ι-, κ-, and λ-carrageenans have varying degress of sulfation, they may be studied comparatively for differences in protective, antiviral, and immunosuppression activities