The system of low-molecular-weight carrageenans and agaroids from the room-temperature-extracted fraction of Kappaphyeus alvarezii

The room-temperature-extracted fraction from the red seaweed Kappaphycus alvarezii consists mainly of low-molecular-weight carrageenans, with structural dispersion around a basic κ-pattern. This dispersion results from: (a) low percentages of 3,6-anhydrogalactose and the presence of precursor units; (b) important quantities of 6-Ο-methyl β-D-galactose (4-sulfate) residues; (c) significant amounts of i-repeating structure, and (d) small amounts of non-sulfated and disulfated β-D-galactose residues. Significant quantities of β-L-galactose units suggest the presence of agaroids, as it has been reported in several other carrageenophytes.