Structural and compositional characteristics of hybrid carrageenans from red algae Chondracanthus chamissoi

► The precise structure of carrageenans from Chondracanthus chamissoi was elucidated. ► A series of hybrid carrageenan-derived oligosaccharides, e.g., κ-κ, κ-μ and κ-ι, were obtained by mild acid hydrolysis. ► A series of even-numbered κ-carrageenan-derived oligosaccharides were obtained by reductive acid hydrolysis.