Unique carotenoids in the terrestrial cyanobacterium Nostoc commune NIES-24: 2-hydroxymyxol 2'-fucoside, nostoxanthin and canthaxanthin.
Cyanobacteria produce some carotenoids. We identified the molecular structures, including the stereochemistry, of all the carotenoids in the terrestrial cyanobacterium, Nostoc commune NIES-24 (IAM M-13). The major carotenoid was beta-carotene. Its hydroxyl derivatives were (3R)-beta-cryptoxanthin, (3R,3'R)-zeaxanthin, (2R,3R,3'R)-caloxanthin, and (2R,3R,2'R,3'R)-nostoxanthin, and its keto derivatives were echinenone and canthaxanthin. The unique myxol glycosides were (3R,2'S)-myxol 2'-fucoside and (2R,3R,2'S)-2-hydroxymyxol 2'-fucoside. This is only the second species found to contain 2-hydroxymyxol. We propose possible carotenogenesis pathways based on our identification of the carotenoids: the hydroxyl pathway produced nostoxanthin via zeaxanthin from beta-carotene, the keto pathway produced canthaxanthin from beta-carotene, and the myxol pathway produced 2-hydroxymyxol 2'-fucoside via myxol 2'-fucoside. This cyanobacterium was found to contain many kinds of carotenoids and also displayed many carotenogenesis pathways, while other cyanobacteria lack some carotenoids and a part of carotenogenesis pathways compared with this cyanobacterium.
Takaichi
Shinichi
S
Department of Biology, Nippon Medical School, Nakahara, Kawasaki, Japan. takaichi@nms.ac.jp
Maoka
Takashi
T
Mochimaru
Mari
M
D053898:Biosynthetic Pathways; D016644:Canthaxanthin / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D005643:Fucose / Q000031:analogs & derivatives* / Q000032:analysis; D015394:Molecular Structure; D050501:Nostoc commune / Q000737:chemistry* / Q000378:metabolism; D013057:Spectrum Analysis; D024341:Xanthophylls / Q000032:analysis*
C533812:2-hydroxymyxol-2'-fucoside; D024341:Xanthophylls; C533811:nostoxanthin; D005643:Fucose; D016644:Canthaxanthin