A chromatographic study of agar extracts from the red alga Ahnfeltia tobuchiensis

The red alga Ahnfeltia tobuchiensis was successively extracted six times, a nd the resulting crude agar extracts were characterized by high-performance size exclusion chromatography. An agar fraction (13.1-42.7%), protein-poly saccharide contaminants (53.4%-77.2%), and low-molecular mass impurities (3 .9-9.7%) were found in the extracts. In successive extracts, the degree of methylation of agar molecules was shown to increase, the methyl groups bein g located only in position 2 of 3,6-anhydro-alpha-L-galactose residues. The differences in molecular mass and sulfate content between the different ag ar extracts were insignificant. An increase in the methylation degree of ag ars does not affect their gelation temperature and only decreases the melti ng point of the agar gels.