Table 1.

Identification of the carotenoids in three different Erythrobacter species. Strain 1, E. flavus strain KJ5; 2, E. longus; 3, E. nanhaesediminis. +, detected and −, not detected. The chemical structures of the major carotenoid identified are presented in Figure S3.

Peak No	Identification	tR (min)	λmax (nm)	Capacity Factor (k’)	Molecular Ion	Fragment Ion	Ref.	Strain
								1	2	3
1	Erythroxanthin sulfate	15.3	464	8.71	677.5 [M − Na]−	80.3 [SO3]−, 97.3 [HSO4 ]−, 597.6 [M − SO3]−	[29,36]	−	+	−
2	Ketonostoxanthin	17.0	463, 475	9.83	614.6 [M]+	596.0 [M − 18]+	[36]	−	−	+
3	Nostoxanthin sulfate	17.6	(427), 452, 480	10.18	679.6 [M − Na]−	97.3 [HSO4]−	[36]	+	−	−
4	Caloxanthin sulfate	19.9	(427), 453, 480	11.69	663.6 [M − Na]−	97.2 [HSO4]−	[29,36]	+	+	−
5	Nostoxanthin	20.8	(427), 452, 480	12.27	600.5 [M]+	508.6 [M − 92]+	[28,36]	+	+	+
6	Caloxanthin sulfate isomer	21.9	(427), 453, 480	12.94	663.4 [M − Na]−	97.3 [HSO4]−	−	+	−	−
7	Ketonostoxanthin cis isomer	22.7	353, 454, (472)	13.46	614.5 [M]+	596.4 [M − 18]+, 582.4 [M − 32]+	−	−	−	+
8	Zeaxanthin sulfate	24.0	(427), 453, 481	14.31	647.5 [M − Na]−	97.6 [HSO4]−	−	+	−	−
9	Caloxanthin	25.0	(427), 453, 480	14.92	584.4 [M]+	492.0 [M − 92]+	[28,36]	+	+	+
10	Unidentified	27.0	468	16.20	582.5 [M]+	536.5 [M − 46]+, 490.3 [M − 92]+	−	−	−	+
11	Zeaxanthin sulfate cis isomer	27.1	331, (427), 452, 476	16.27	647.6 [M − Na]−	97.2 [HSO4]−	−	+	−	−
12	Bacterio- rubixanthinal	27.8	510	16.68	596.5 [M]−	550.4 [M − 46]−	[28,36]	−	+	−
13	Zeaxanthin	28.5	(426), 453, 478	17.15	568.5 [M]+	476.5 [M − 92]+	[5,28,32]	+	+	+
14	Zeaxanthin isomer	32.6	(426), 453, 479	19.77	568.5 [M]+	476.6 [M − 92]+	−	+	−	−
15	β-cryptoxanthin	33.4	(426), 453, 479	20.24	552.5 [M]+	460.4 [M − 92]+	[28,36]	+	−	−
16	BChl a	33.6	362, 601, 769	20.39	911.3 [M]+	783.5 [M − 128]+	[8]	−	+	−
17	β-carotene cis isomer	36.7	340, (425), 449, 474	22.37	536.1 [M]+	444.4 [M − 92]+	−	+	−	−
18	β-carotene	37.2	(426), 452, 478	22.71	536.5 [M]+	444.3 [M − 92]+	[5,28,32]	+	+	+