D. Carotenoids
47
111
ο
113
Another pair of xanthophylls that proved to have acetylenic linkages
were first isolated by Strain and co-workers (1944) from a number of diatoms
including Navicula torquatum and Isthmia nervosa. Strain et al. (1944)
designated the new pigments diatoxanthin (114) and diadinoxanthin (115)
and noted that the visible absorption spectra of the two carotenoids strongly
114
HO
115
resembled those of zeaxanthin (110) and of lutein (106), respectively. Chapman (1966) isolated diatoxanthin (114) from Isochrysis galbana and Mallams
et al. (1967) assigned structure 114 to the pigment on the basis of spectral
comparisons. The companion xanthophyll of diatoms, diadinoxanthin, which
has also been isolated from dinoflagellates and from Euglena gracilis, is the
epoxide of diatoxanthin (114) and has structure 115 (Aitzetmüller et al, 1968).
47
111
ο
113
Another pair of xanthophylls that proved to have acetylenic linkages
were first isolated by Strain and co-workers (1944) from a number of diatoms
including Navicula torquatum and Isthmia nervosa. Strain et al. (1944)
designated the new pigments diatoxanthin (114) and diadinoxanthin (115)
and noted that the visible absorption spectra of the two carotenoids strongly
114
HO
115
resembled those of zeaxanthin (110) and of lutein (106), respectively. Chapman (1966) isolated diatoxanthin (114) from Isochrysis galbana and Mallams
et al. (1967) assigned structure 114 to the pigment on the basis of spectral
comparisons. The companion xanthophyll of diatoms, diadinoxanthin, which
has also been isolated from dinoflagellates and from Euglena gracilis, is the
epoxide of diatoxanthin (114) and has structure 115 (Aitzetmüller et al, 1968).