Table 1.

Main carotenoids from marine microalgae.

Main Carotenoid	Chemical IUPAC Name/Chemical Structure	Concentration	Microalga	Other Carotenoids	Remarks	References
β-carotene	β,β-carotene	10%–13% DW	Dunaliella salina	zeaxanthin, lutein, α-carotene	occur mostly as a mixture of 9-cis and all-trans, but also other cis isomers	[31,32,33,34,35,36,37]
		50% TC (TC = 0.9% DW)	Chlorella zofingiensis	canthaxanthin (25% TC or 97% DW), astaxanthin (0.7% DW)
		80% TC	Arthrospira	astaxanthin, lutein β-cryptoxanthin, zeaxanthin, echinenone, oscillaxanthin, myxoxanthophyll
astaxanthin(as 3S,3′S isomer)	3,3′-dihydroxy-β,β-carotene-4,4′-dione	up to 7% DW; 75% TC	Haematococcus pluvialis	β-carotene, lutein, canthaxanthin, neoxanthin, violaxanthin, zeaxanthin, echinenone	occur as a racemic mixture of mainly mono- and diesters (ca. 73% TC), but also as freeastaxanthin	[21,38,39,40,41,42]
lutein	β,ε-carotene-3,3′-diol	0.2%–0.4% DW	C. pyrenoidosa	violaxanthin, loroxanthin, α- and β-carotene		[43]
canthaxanthin	β,β-carotene-4,4′-dione	4.75% DW	Coelastrella striolata var. multistriata	astaxanthin 0.15% DW, β-carotene 0.7% DW		[37]
canthaxanthin lutein	β,β-carotene-4,4′-dione β,ε-carotene-3,3′-diol	45% TC	C. vulgaris	astaxanthin 12.5% TCviolaxanthin		[44,45]
fucoxanthin	acetic acid [(1S,3R)-3-hydroxy-4-[(3E,5E,7E,9E,11E,13E,15E)-18-[(1S,4S,6R)-4-hydroxy-2,2,6-trimethyl-7-oxabicyclo[4.1.0]heptan-1-yl]-3,7,12,16-tetramethyl-17-oxooctadeca-1,3,5,7,9,11,13,15-octaenylidene]-3,5,5-trimethylcyclohexyl] ester	1.65%DW	P. tricornutum	diadinoxanthin, eaxanthin, neoxanthin, violaxanthin, β-carotene	occur mainly as all-trans but also as cis isomers	[46,47,48]
		1.8% DW	Isochrysis aff. galbana			[49]
		0.52% DW	Cylindrotheca closterium			[50]
		up to 2.2% DW	Odontella aurita	diadinoxanthin, β-carotene		[51]
zeaxanthin	β,β-carotene-4,4′-diol	97.4% TC	P. cruentum	β-carotene		[52]
echinenone (extracelular)	β,β-carotene-4-one	0.17% DW	B. braunii	botryoxanthins A and B—0.03% DW braunixanthins 1 and 2—0.06% DW	extracellular pigments are produced and secreted into the intercellular matrix	[53]
Lutein (intracelular)	β,ε-carotene-3,3′-diol	up to 0.16% DW		neox/loroxanthin 0.042% DW α- and β-carotene 0.031% DW violaxanthin 0.02% DW
violaxanthin	(1S,4S,6R)-1-[(1E,3E,5E,7E,9E,11E,13E,15E,17E)-18-[(1S,4S,6R)-4-hydroxy-2,2,6-trimethyl-7-oxabicyclo[4.1.0]heptan-1-yl]-3,7,12,16-tetramethyloctadeca-1,3,5,7,9,11,13,15,17-nonaenyl]-2,2,6-trimethyl-7-oxabicyclo[4.1.0] heptan-4-ol		C. ellipsodea	antheraxanthin, zeaxanthin		[45]

TC = total carotenoids.