Carotene structure

Diels-Alder reaction of, 575 electrostatic potential map of, 576 evidence for, 575 structure of, 576 Bergman, Torbern, 2 Bergstrom, Sune K., 1068 Beta anomer, 984 Beta-carotene, structure of, 172 industrial synthesis of, 722 UV spectrum of, 504 Beta-diketone, 851... 

There are of course many other approaches to the p-carotene structure (ref.48) such as one based on the combination of 2Ci6 and a C9 intermediate, another on the combination of 2Cj4 with a C,2 component and also by the use of reactants with a Cjo dialdehyde. However... 

Therapeutic Function As a vitamin A precursor sunscreen agent Chemical Name f3-Carotene Structural Formula ... 

FIGURE 3.9 Examples of carotene structural diversity (a) lycopene ( /,t t-carotene) displaying the carbon number system for carotenes (b) the systematic nomenclature end group designations for carotenes and (c) a-carotene ( 3,e-carotene) and P-carotene (P,P-carotene). 

Fig. 7.35 Structures, numbering, trivial names, and systematic names in brackets) of major carotenes Greek letters at the terminal residues are identical with those of the systematic names. The systematic name for a-carotene (structure not shown) is (6 i )-P,e-carotene...

Lycopene, C4gHgg, the colouring matter of tomatoes, differs from the carotenes structurally in being a non-cyclic hydrocarbon. 

The structural chemistry of the visual process beginning with 3 carotene was de scribed in the boxed essay entitled Imines in Biological Chemistry in Chapter 17... 

Fig. 1. Carotenoid pigments -carotene (42), P-apo-8 -carotenal (44), and canthaxanthin (43) = structure (42) with ketone groups at the 4 and 4 positions.

Why are some organic compounds colored while others aren t /3-Carotene, the pigment in carrots, is purple-orange, for instance, while cholesterol is colorless. The answer involves both the chemical structures of colored molecules and the way we perceive light. 

Carotene, a yellow food-coloring agent and dietary source of vitamin A, can be prepared by a double Wittig reaction between 2 equivalents of jS-ionvlideneacetaldehyde and a diylide. Show the structure of the /0-carotene product. 

The molecular structure of astaxanthin. p-carotene is the same molecule where the =0 and —OH groups are replaced with hydrogens. 

Hypervitaminosis A is characterized by hepatomegaly, cerebral edema and bone structure alterations. (3-Carotene... 

As further described in the section on beta-carotene, organic dyes owe their colors to resonance structures in the molecule, where charges are free to move in the molecule at frequencies that fall in the range of visible light. 

The fine structures of P-carotene and zeaxanthin are different becanse of different side groups and slightly different electronic confignrations. 

The carotenoids are the most widely distributed group of pigments, occur naturally in large quantities, and are known for their structural diversity and various functions. The carotenoids constitnte a widespread class of natural pigments that occur in all three domains of life in the eubacteria, the archea, and the eucarya. Carotenoids are ubiquitous organic molecules, but they are not produced by the human body. They have been fonnd to be essential to human health based on the nutritional understanding of vitamin A (retinol) and (i-carotene. ... 

FIGURE 2.2.1 Structures of common carotenoids (I. Main carotenes. II. Xanthophylls. III. Animal carotenoids). 

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