Identity of Tunaxanthin A with Oxyxanthin 45

Salmoxanthin, Deepoxysalmoxanthin, and 7,8-Didehydrodeepoxysalmoxanthin from the Salmon Oncorhynchus keta

“…From the results of deepoxysalmoxanthin described above, it is assumed that substitution at C-6‘ (OH-6‘) has no influence on both the sign of the Cotton effects and the general shape of the spectrum. Therefore, according to the additivity rule of CD spectra, the CD spectrum of 1 corresponded to that of the calculated CD of 1/2 (3 S ,5 R ,-6 S ,3‘ S ,5‘ R ,6‘ S )-violaxanthin , (having a 3-hydroxy-5,6-epoxy end group) and 1/2 (3 S ,6 S ,3‘ S ,6‘ S )-tunaxanthin (tunaxanthin A) , (having a 3-hydroxy-ε end group), as shown in Figure . From the results described above, it seemed that 1 has the same chiralities at C-3, C-5, and C-6 as (3 S ,5 R ,6 S ,3‘ S ,5‘ R ,6‘ S )-violaxanthin, and at C-3‘ and C-6‘ as tunaxanthin A.…”