C-Carotene

Caro s acid, H2SOS. See persulphuric acid, carotene, C4qHs6- M.p. 18 J-J82°C. Carotene... 

P = phytoene PF = phytofluene -C = -carotene L = lycopene y-C = y-carotene p-C = p-carotene Lut = lutein Viola = violaxanthin Neo = neoxanthin d.p.b. days post breaker. 

ERNST s and sandmann g (1988) Poly-c carotene pathway in the Scenedesmus mutant C-6D , Arch Microbiol, 150, 590-94. 

FIGURE 1. Chemical structures of various polyenes (a) unsubstituted and a,< disubstituted polyenes (b) retinal (c) -carotene... 

Bauernfeind, J. C. "Carotenes as Colorants and Vitamin A Precursors Academic Press, New York and London. 1981, p. arlii. 

The syntheses of methyl bixin (24) and other natural carotenoids were mentioned above. A biogenetically inspired synthesis of e-carotene used the titanium tetrachloride complex of lycopene (16). Dehydrolycopene was also isolated. Two more syntheses of ) -carotene (2) have been reported which use intermediates in the synthesis of vitamin A (see Scheme 2). Although ll-cis-j5-carotene was produced it is rapidly isomerised to the all-frons form. The cross-conjugated system (72) has a previously unknown chromophore. Another example of this system, but with an additional 4 -oxo-group, was synthesised by Surmatis et al. in a study of the synthesis of keto carotenoids. They prepared echinenone (73) and the two protected 3,3 -dioxo-j8-carotene compounds (74) and (75). Treatment of the ketal with sulphuric acid gave mainly 3,3 -dioxo- -carotene (76) while hydrochloric acid gave 3,3 -dioxo-c-carotene (77). Under both conditions the enol ether gave the latter product. 

Metabolism in Animals. The conversion of [ C]-/ -carotene into its 2-hydroxy-and 3-hydroxy-metabolites by two species of moths has been demonstrated. The sea anemone Metridium senile can utilize dietary canthaxanthin but not jS-carotene, echinenone (/3,/3-caroten-4-one), or zeaxanthin to produce asta-xanthin in its ovaries. The chirality (3 5) of the 3-hydroxy-e-ring carotenoids a-doradexanthin (14) and lutein (15) of goldfish suggests that these carotenoids... 

The Heliobacteriaceae only have Cj acyclic carotenes, 4,4"-diapocarotenes, instead of the usual carotenoids (Fig. 11 Takaichi et al., 1997b). 4,4"-Diaponeurosporene is the major carotene, and diapophytoene, diapophytofluene, diapo-C-carotene and diapolycopene are also found as minor components. Two genes encoding enzymes in the early steps of diapocarotene biosynthesis have been... 

Bo-Xan p,c-Carotene-3,3 -diol p,s-Carotene-3,3-diol, (3R,3 R,6 R)- EINECS 204-840-0 Lutein all-trans-Lutein Lutein, ali-trans- Lutein ester Luteine NSC 59193 Vegetable lutein Vegetable luteol Xanthophyll all-trans-(-r)-Xanthophyll Xanthophyll, all-trans-(+)-. The yellow pigment occurring in green vegetafon and some animal products. Yellow or violet prisms mp = 196° [af D = 160° (c = 0.7, CHCI3) Xm = 340, 457, 488 nm (e = 6607, 123027, 112202, CsHs) insoluble in H2O, very soluble in CeHs, EtOH, EtaO,... 

Analogs of Diethylaminoethylphenylethers. Treatment with analogs of diethylaminoethylphenylethers (Table III) gave a similar carotenoid pattern. Neurosporene content did not increase as much as previously, although C-carotene content did show a large increase. The cyclic carotenes, with the exception of y-carotene, did not... 

If this hypothesis is true, one would also expect to find poly-cis-C-carotene, -phytofluene, and -phytoene present in the fruit. Poly-cis induction appears to differ from the lycopene inducer in another respect. In addition to gene derepression, the lycopene inducers inhibit the cyclase(s), causing lycopene to accumulate at the expense of the cyclic carotenes. The accumulation of significant amounts of poly-cis-y-carotenes I and II indicates that the cyclase(s) is not inhibited by the poly-cis inducers and that their only apparent function is to derepress the recessive gene. 

Direct interaction with the enzyme [Pg.191]

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