Of fucoxanthin

Most of this amount is in the form of fucoxanthin in various algae and in the three main carotenoids of green leaves lutein, violaxanthin, and neoxanthin. Others produced in much smaller amounts but found widely are p-carotene and zeaxanthin. The other pigments found in certain plants are lycopene and capsanthin (Figure 2.2.1). Colorant preparations have been made from all of these compounds and obviously the composition of a colorant extract reflects the profile of the starting material. Carotenoids are probably the best known of the food colorants derived from natural sources. ... 

In iron-deplete cells, the pool of fucoxanthins was not stable over the day. The ratio of 19,-hexanoyloxyfucoxanthin to fucoxanthin... 

Fig. 3 Daily dynamics of the fucoxanthin pigments plotted l -hexanoyloxyfucoxanthin to fucoxanthin (hexa/fuco). alongside irradiance (photons m-2 s 1 solid line) in iron- (B, E) Ratio of fucoxanthin to chlorophyll a. (C, F) Ratio...

A study on the effect of fucoxanthin on the viability of human cancer cells Caco-2, revealed that after 72 hr of incubation with 7.6 mM of fucoxanthin, the number of viable cells decreased by 39% compared to the control (Fig. 26.7). 

Figure 26.6. Effect of fucoxanthin on DNA fragmentation in HL-60 cells. HL-60 cells (1 - 105 cells/ml) were incubated with different concentration of fucoxanthin for 24h (A) and different incubation time with 11.3mM fucoxanthin (B). DNA fragmentation was analyzed by sandwich ELISA with biotin labeled anti-histone antibody and peroxidase conjugated anti-DNA antibody.The level of DNA fragmentation was expressed as an enrichment factor defined as absorbance (405 nm) of cells treated with fucoxanthin relative to that of untreated cells. Source Hosokawa et al., 1999.

Hosokawa, M., Wanezaki, S., Miyauchi, K., Kurihara, H., Kohno, H., Kawabata, J., Odashima, S., and Takahashi, K. 1999. Apoptosis inducing effect of fucoxanthin on human leukemia cell HL-60. Food Sci. Technol. Res., 5, 243-246. 

Maoka, T., Fujiwara, Y., Hashimoto, K., and Akimoto, N. 2007. Characterization of fucoxanthin and fucoxanthinol esters in the Chinese Surf Clam, Mactra chinensis. 

Nishino, H., Tsushima, M., Matsuno, T., Tanaka, Y., Okuzmi, J., Murakoshi, M., Satomi, Y., Takayasu, J., Tokuda, H., Nishino, A., and Iwashima, A. 1992. Anti-neoplastic effect of halocynthiaxanthin, ametabolite of fucoxanthin. Anticancer Drugs, 3, 493 197. 

Okuzumi, J., Nishino, H., Murokoshi, M., Iwashima, A., Tanaka, Y., Yamane, T., Fujita, Y., and Takahashi, T. 1990. Inhibitory effects of fucoxanthin, natural carotenoids on N-MYC expression and cell cycle progression in human malignant tumor cells. Cancer Lett., 55, 75-81. 

Satomi, Y.,Tokuda, H., Fuji, H., Shimidzu, N.,Tanaka, Y., and Nishino, H. 1996. Antitumor promoting activity of fucoxanthin, natural carotenoids. J. Kyoto Pref. Univ. Med., 105,739-743. 

The end groups of acetylenic carotenoids like alloxanthin (8), found in algae and marine organisms, are structurally related to the end groups of fucoxanthin (9), the most abundant natural carotenoid . The allene and acetylene bonds are known to be biogenetically linked in polyacetylenes and the same seems likely to apply to... 

DETronrud, MF Schmid and BW Mathews (1986) Structure and x-ray amino acid sequence of a bacteriochlo-rophyll a protein from Prosthecochloris aestuarii refined at 1.9 resolution. J Mol Biol 188 443-454 T Katoh, M MImuro and S Takalchl (1989) Light-harvesting particles Isolated from a brown alga, DIctyota dichotoma. A supramolecular assembly of fucoxanthin-chlorophyll-protein complexes. Biochim Biophys Acta 976 233-240... 

Fig 6. Absorption and second-derivative spectra of intact fucoxanthin-chlorophyll- a/c protein assembly (FCPA) at room temperature (A, top) and 77 K (A, bottom). Absorption spectra of intact and Triton-treated FCPA (B, top) and their difference spectrum between the two (B, bottom). Figure source Katoh, Mimuro and Takaichi (1989) Light-harvesting particles isolated from a brown alga, Dictyota dichotoma. A supramolecular assembly of fucoxanthin-chlorophyll-protein complexes. Biochim BiophysActa 968 236,237. 

Whether carotenoid fluorescence originates from the S2- So or S ->So transition appears to depend on the number of conjugated double bonds, i.e., the chain length, and possibly other molecular-structural factors. For instance, the fluorescence from both (3-carotene and spheroidene, each ofwhich has 10 conjugated double bonds, originates from the S2->So transition, while that of fucoxanthin, which has 8 conjugated double bonds, displays the Stokes-shifted Si- Socmission. 

T Katoh, M Mimuro and S Takaichi (1989) Light-harvesting particles isolated from a brown alga, Dictyota dichotoma. A supramolecular assembly of fucoxanthin-chlorophyll-protein complexes. Biochim Biophys Acta 976 233-240... 

T Katoh and T Ehara (1990) Supramolecular assembly of fucoxanthin-chlorophyll-protein complexes isolated from a brown alga, Petalonia fascia. Electron microscopic studies. Plant Cell Phyiol 31 439-447... 

DL Dexter (1953) A theory of sensitized luminescence in solids. J Chem Phys 21 836-860 T Gillbro and RJ Cogdell (1989) Carotenoid fluorescence. Chem Phys Lett 158 312-316 T Katoh, U Nagashima and M Mimuro (1991) Fluorescence properties of the allenic carotenoid fucoxanthin Implication for energy transfer in photosynthetic pigment systems. Photosynthesis Res 27 221-226 AP Shreve, JK Trautman, TG Owens and AC Albrecht (1991) A femtosecond study of electronic state dynamics of fucoxanthin and implication for photosynthetic carotenoid-to-chlorophyll energy transfer mechanisms. Chem Phys 154 171-178... 

Repeta D.J. (1989) Carotenoid diagenesis in recent marine sediments II. Degradation of fucoxanthin to loliolide. Geochim. Cosmochim.Acta 53, 699—707. 

The defensive excretion of the grasshopper Romalea microptera contains the allenic ketone (10). This structure is clearly related to neoxanthin (57). Racemic samples of (10) were synthesised by two routes (Scheme 5) and, although there were some differences between the two products, their n.m.r. spectra show that they belong to the natural series and that they are clearly different from the photochemically synthesised isomer (3-OH, 90, R = Ac). The stereochemistry of the synthetic racemate was shown by X-ray crystallography to be the same as an optically active sample derived from the degradation of fucoxanthin. The absolute stereochemistry of the latter sample presumably also applies to the grasshopper ketone itself. 

Shreve AP, Trautmann TG, Owens TG and Albrecht AC (1991) A femtosecond study of electronic state dynamics of fucoxanthin and implications for photosynthetic carotenoid to chlorophyll energy transfer mechanisms. Chem Phys 154 171-178... 

Fig. (17). Formation of blue oxonium ions via cyclic hemiketals upon treatment of fucoxanthin (42) with strong acid, and conversion of the blue oxonium ion to yellow hemiketal with base Reprinted with permission from [10], Copyright 1994 Acta Chemica Scandinavica.

The synthesis of fucoxanthin (121), reported by Ito is clearly a highlight in the field of carotenoid synthesis [32-74], The carotenoid was synthesized according to the strategy Cis + Cio + Ci5 = C40 with the Cio-dialdehyde 45 as central unit. As the allenic precursor 103 for the Ci5-end group 122 had previously been prepared for the synthesis of peridinin (108) the emphasis was on the preparation of the 3-hydroxy-8-oxo-p end group 123. 

Figure 6. SFC-MS total ion current chromatogram and methane chemical ionization spectrum of fucoxanthin.

---