2 Carotenoids in Phototrophic Microalgae …
23
algal divisions and classes, and are summarized in Table 2.1 based on our results
(Takaichi and Mimuro 1998; Yoshii et al. 2005; Takaichi and Mochimaru 2007;
Takaichi 2011) and some references (Rowan 1989; Bjørnland and Liaaen-Jensen
1989; Liaaen-Jensen 1990; Mackey et al. 1996; Jeffrey and Vesk 1997).
Many cyanobacteria contain β-carotene, zeaxanthin, echinenone, and myxol
pentosides (myxoxanthophyll), while certain species lack some of these, and others
contain additional carotenoids, such as nostoxanthin, canthaxanthin, and oscillol
dipentoside (Table 2.1, Fig. 2.1) (Takaichi and Mochimaru 2007). In addition,
the carotenoid compositions of cyanobacteria are different from those of chloroplasts in algae; consequently, during symbiosis of cyanobacteria to eukaryotic cells,
carotenoids may have been considerably restructured (Takaichi and Mochimaru
2007). Note that, since the name of myxoxanthophyll cannot specify the glycoside
moieties, we proposed the name of myxol glycosides to specify the glycosides, such
as myxol 2
-α-l-fucoside, 4-ketomyxol 2
-rhamnoside, and oscillol dichinovoside
(Takaichi et al. 2001; Takaichi and Mochimaru 2007; Takaichi 2011). Additionally, most species contain chlorophyll a, whereas some species contain additional
chlorophylls b, d, or f (Table 2.1).
Carotenoid composition is very diverse in Rhodophyta (red algae). They can
be divided into three groups based on their carotenoid composition and phylogenetics: the unicellular group contains only β-carotene and zeaxanthin (ZEA-type);
whereas the macrophytic group contains additional antheraxanthin (ANT-type); and
the Bangiophyceae and some others contain α-carotene and lutein along with ZEAtype carotenoids (LUT-type) (Table 2.1, Fig. 2.1) (Takaichi et al. 2016). The Glaucophyta contains only β-carotene and zeaxanthin, and the major carotenoid in the
Cryptophyta is acetylenic alloxanthin. The latter group also contains α-carotene and
its acetylenic derivatives, crocoxanthin and monadoxanthin, which are only found
in this division (Takaichi et al. 2016).
The Heterokontophyta, Haptophyta, and Dinophyta contain β-carotene and its
derivatives as well as chlorophyll c (Table 2.1, Fig. 2.1). These divisions, except for
the Eustigmatophyceae, which lack chlorophylls c, contain the unique acetylenic
carotenoids of diadinoxanthin and diatoxanthin. Fucoxanthin and its derivatives
are found in only four classes of the Heterokontophyta (Chrysophyceae, Raphidophyceae, Bacillariophyceae, and Phaeophyceae) and in the Haptophyta and Dinophyta. Peridinin and its derivatives are found only in the Dinophyta. In fact, fucoxanthin and peridinin exhibit unique structures (Fig. 2.1) and are class-specific
carotenoids (Table 2.1) (Takaichi 2011).
The Euglenophyta, Chlorarachniophyta, and Chlorophyta contain the same
carotenoids including β-carotene, violaxanthin, 9
-cis neoxanthin (Takaichi and
Mimuro 1998), and lutein, as well as chlorophyll a and b, which are found in land
plants (Table 2.1, Fig. 2.1). Some classes contain additional carotenoids, such as
loroxanthin, siphonaxanthin, and prasinoxanthin, which are derivatives of lutein,
and are class specific (Takaichi 2011).
Note that identification of some carotenoids is lacking because they have not yet
been fully investigated. Moreover, some algal names have been changed due to new
developments in taxonomic technology and phylogenetic classification.
23
algal divisions and classes, and are summarized in Table 2.1 based on our results
(Takaichi and Mimuro 1998; Yoshii et al. 2005; Takaichi and Mochimaru 2007;
Takaichi 2011) and some references (Rowan 1989; Bjørnland and Liaaen-Jensen
1989; Liaaen-Jensen 1990; Mackey et al. 1996; Jeffrey and Vesk 1997).
Many cyanobacteria contain β-carotene, zeaxanthin, echinenone, and myxol
pentosides (myxoxanthophyll), while certain species lack some of these, and others
contain additional carotenoids, such as nostoxanthin, canthaxanthin, and oscillol
dipentoside (Table 2.1, Fig. 2.1) (Takaichi and Mochimaru 2007). In addition,
the carotenoid compositions of cyanobacteria are different from those of chloroplasts in algae; consequently, during symbiosis of cyanobacteria to eukaryotic cells,
carotenoids may have been considerably restructured (Takaichi and Mochimaru
2007). Note that, since the name of myxoxanthophyll cannot specify the glycoside
moieties, we proposed the name of myxol glycosides to specify the glycosides, such
as myxol 2
-α-l-fucoside, 4-ketomyxol 2
-rhamnoside, and oscillol dichinovoside
(Takaichi et al. 2001; Takaichi and Mochimaru 2007; Takaichi 2011). Additionally, most species contain chlorophyll a, whereas some species contain additional
chlorophylls b, d, or f (Table 2.1).
Carotenoid composition is very diverse in Rhodophyta (red algae). They can
be divided into three groups based on their carotenoid composition and phylogenetics: the unicellular group contains only β-carotene and zeaxanthin (ZEA-type);
whereas the macrophytic group contains additional antheraxanthin (ANT-type); and
the Bangiophyceae and some others contain α-carotene and lutein along with ZEAtype carotenoids (LUT-type) (Table 2.1, Fig. 2.1) (Takaichi et al. 2016). The Glaucophyta contains only β-carotene and zeaxanthin, and the major carotenoid in the
Cryptophyta is acetylenic alloxanthin. The latter group also contains α-carotene and
its acetylenic derivatives, crocoxanthin and monadoxanthin, which are only found
in this division (Takaichi et al. 2016).
The Heterokontophyta, Haptophyta, and Dinophyta contain β-carotene and its
derivatives as well as chlorophyll c (Table 2.1, Fig. 2.1). These divisions, except for
the Eustigmatophyceae, which lack chlorophylls c, contain the unique acetylenic
carotenoids of diadinoxanthin and diatoxanthin. Fucoxanthin and its derivatives
are found in only four classes of the Heterokontophyta (Chrysophyceae, Raphidophyceae, Bacillariophyceae, and Phaeophyceae) and in the Haptophyta and Dinophyta. Peridinin and its derivatives are found only in the Dinophyta. In fact, fucoxanthin and peridinin exhibit unique structures (Fig. 2.1) and are class-specific
carotenoids (Table 2.1) (Takaichi 2011).
The Euglenophyta, Chlorarachniophyta, and Chlorophyta contain the same
carotenoids including β-carotene, violaxanthin, 9
-cis neoxanthin (Takaichi and
Mimuro 1998), and lutein, as well as chlorophyll a and b, which are found in land
plants (Table 2.1, Fig. 2.1). Some classes contain additional carotenoids, such as
loroxanthin, siphonaxanthin, and prasinoxanthin, which are derivatives of lutein,
and are class specific (Takaichi 2011).
Note that identification of some carotenoids is lacking because they have not yet
been fully investigated. Moreover, some algal names have been changed due to new
developments in taxonomic technology and phylogenetic classification.