Carotenoids peridinin

Hoffman, E., et al., 1996. Structural basis of light harvesting by carotenoids Peridinin-chlorophyll-protein from Amphidinium carterae. Science 272 1788-1791. 

The AE reactions on 2,5,5-trisubstituted allyl alcohols have received little attention, due in part the limited utility of the product epoxides. Selective ring opening of tetrasubstituted epoxides are difficult to achieve. Epoxide 39 was prepared using stoichiometric AE conditions and were subsequently elaborated to Darvon alcohol. Epoxides 40 and 41 were both prepared in good selectivity and subsequently utilized in the preparation of (-)-cuparene and the polyfunctoinal carotenoid peridinin, respectively. Scheme 1.6.12... 

Carotenoids Peridinin Fucoxanthin 19 -butanoyloxyfucoxanthin 19 -hexanoyloxyfucoxanthin Alloxan thin Prasinoxanthin Lutein Zeaxanthin Dinoflagellates Diatoms Pelagophytes Haptophytes Cryptophytes Prasinophytes Chlorophytes Cyanobacteria, chlorophytes... 

Eukaryotic plants and cyanobacteria. Photosynthetic dinoflagellates, which make up much of the marine plankton, use both carotenoids and chlorophyll in light-harvesting complexes. The carotenoid peridinin (Fig. 23-29), which absorbs blue-green in the 470- to 550-nm range, predominates. The LH complex of Amphidinium carterae consists of a 30.2-kDA protein that forms a cavity into which eight molecules of peridinin but only two of chlorophyll a (Chi a) and two molecules of a galactolipid are bound (Fig. 23-29).268... 

The unique water-soluble peridinin- Chi a-protein (PCP) complexes are found in many dynoflagellates in addition to intrinsic membrane complexes. [64] It contains Chi a and the unusual carotenoid peridinin in stoichiometric ratio of 1 4. Unlike other families of antennas, the main light-harvesting pigments are carotenoids, not chlorophylls. The structure of the PCP consists of a protein that folds into four domains, each of which embeds four peridinin molecules and a single Chi a. The protein then forms trimers, suggested to be located in the lumen [64] in contact with both LHCI and LHCII [66], allowing efficient EET to occur. 

A survey10 of several dinoflagellates has revealed the presence of some interesting new carotenoids in addition to the main carotenoid peridinin [3 -acetoxy-5,6-epoxy-3,5 -dihydroxy-6, 7 -didehydro-5,6,5, 6 -tetrahydro-12, 13, 20 -trinor-/3,/ -caroten-19,11-olide (19)]. Pyrrhoxanthin was assigned the trinor structure 3 -acetoxy-5,6-epoxy-3-hydroxy-7, 8 -didehydro-5,6-dihydro-12, 13, 20 -trinor-/3,/3-caroten-19,11-olide (20) from a consideration of its spectroscopic properties and by chemical correlation with peridinin, and dinoxanthin was shown to be an acetate of neoxanthin, i.e. 3 -acetoxy-5,6-epoxy-6, 7 -didehydro-5,6,5, 6 -tetrahydro-/3,j8-carotene-3,5 -diol (11). Small amounts were also obtained of pyrrhoxanthinol and peridininol which were shown to be the deacetylated analogues (21) and (22) of pyrrhoxanthin and peridinin respectively. 

Katsumura and collaborators [137-139] reported the total synthesis of a polyfimctional carotenoid, Peridinin 314 (Scheme 101). Diene-allenyl sulfone 312 was combined with unsaturated aldehyde 313 using NaHMDS in THF. The product was obtained in 50% yield as a mixture of isomers EjZ 25/75. 

Fig. 5. Crystal structure ofthe A. carterae PCP monomer. (A) stereogram ofthe ribbon model ofthe PCP monomer. The scaffold formed by the helices is likened to a boat the various parts of a boat (bow, stern, deck and keel) are marked. The chromophores in the hydro-phobic cavity ofthe monomer complex are likened to "cargos. (B) stereogram ofthe arrangement of peridinins and chlorophyll in the N-terminal domain [oniy two peridinins ofthe C-terminai domain are shown by thinner iines]. Figure source Hofmann, Wrench, Sharpies, Hiller, Werte and Diederichs (1996) Structural basis of light harvesting by carotenoids Peridinin-chlorophyll-protein from Amphidinlum carterae. Science 272 1789,1790. A color stereogram of (A) kindiy provided by Dr. Eckhard Hofmann and Dr. Wolfram Weite is shown in Color Plate 7.

Amphidinium carterae also shows precisely where the carotenoid peridinin is located in this antenna complex (Hofmann et al., 1996 Fig. 11). Kiihlbrandt et al. (1994) have provided the atomic level structure of LHCllb, the major light harvesting Chi a/Chl b complex of plants and green algae this has allowed the rationalization of the proposed mechanisms of excitation energy transfer among the Chls. 

Olpp, T. and Bruckner, R. (2006) Total synthesis of the lightharvesting carotenoid peridinin. Angeiv. Chem. Lnt. Ed., 46, 4023-4027. 

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