Carotenoid glycoside isolated and identified from cyanobacterium Cylindrospermopsis raciborskii

The freshwater cyanobacterium Cylindrospermopsis raciborskii was investigated for carotenoid composition. Besides β-carotene, echinenone and (9/9′Z)-echinenone a carotenoid glycoside was found to be the main component. This compound was isolated and subsequently acetylated for structural elucidation. The acetyl derivative was fully characterized by UV–vis, ECD, NMR and HRMS techniques. The detailed 1H and 13C NMR chemical shift assignment of the major carotenoid supported the unequivocal identification of (2′S)-2-hydroxymyxol 2′-α-l-fucoside.