Table 1. Absorption Maxima (λ_max) and Relative Intensities of the Z-Peaks (Q-Ratio) for Geometrical Astaxanthin Isomers Separated and Observed Using Normal-Phase HPLC^a.

		λmax (nm)		Q-ratio
label	isomerb	observed	reportedb	observed	reportedb
i	(xZ)-astaxanthin	457	–	ND	–
ii	(xZ)-astaxanthin	457	–	ND	–
(all-E)	(all-E)-astaxanthin	474	472	ND	–
iii	(xZ)-astaxanthin	462	–	ND	–
(9Z)	(9Z)-astaxanthin	367, 467	365, 465	0.22	0.20
(13Z)	(13Z)-astaxanthin	366, 464	366, 465	0.49	0.52
(15Z)	(15Z)-astaxanthin	366, 467	365, 468	0.54	0.56

^aValues and peak designations are obtained from the chromatograms in Figure 1. −, not assigned. ND, not detected substantially.

^bTentatively assigned in the literature.^12,14,18,19