Synechoxanthin, an aromatic C40 xanthophyll that is a major carotenoid in the cyanobacterium Synechococcus sp PCC 7002

A major aromatic, dicarboxylate carotenoid (> 15% of total) was isolated from the euryhaline cyanobacterium Synechococcus sp. PCC 7002. This compound, which was given the common name synechoxanthin (1), has been assigned the structure (all-E) chi,chi-caroten-18,18'-dioic acid by a combination of spectroscopic (UV-vis, FT-IR, H-1 and C-13 NMR, LC-MS) and chemical methods. This discovery conclusively establishes that some cyanobacteria are capable of synthesizing aromatic carotenoids.