Lycopene is an organic compound classified as a tetraterpene and a carotene. Lycopene is a bright red carotenoid hydrocarbon found in tomatoes and other red fruits and vegetables.
Vitamin A is a fat-soluble vitamin and an essential nutrient for animals. The term "vitamin A" encompasses a group of chemically related organic compounds that includes retinol, retinal, retinoic acid, and several provitamin (precursor) carotenoids, most notably beta-carotene. Vitamin A has multiple functions: it is essential for embryo development and growth, for maintenance of the immune system, and for vision, where it combines with the protein opsin to form rhodopsin – the light-absorbing molecule necessary for both low-light and color vision.
Carotenoids are yellow, orange, and red organic pigments that are produced by plants and algae, as well as several bacteria, archaea, and fungi. Carotenoids give the characteristic color to pumpkins, carrots, parsnips, corn, tomatoes, canaries, flamingos, salmon, lobster, shrimp, and daffodils. Over 1,100 identified carotenoids can be further categorized into two classes – xanthophylls and carotenes.
Retinal is a polyene chromophore. Retinal, bound to proteins called opsins, is the chemical basis of visual phototransduction, the light-detection stage of visual perception (vision).
Carotenoid oxygenases are a family of enzymes involved in the cleavage of carotenoids to produce, for example, retinol, commonly known as vitamin A. This family includes an enzyme known as RPE65 which is abundantly expressed in the retinal pigment epithelium where it catalyzed the formation of 11-cis-retinol from all-trans-retinyl esters.
CRT is the gene cluster responsible for the biosynthesis of carotenoids. Those genes are found in eubacteria, in algae and are cryptic in Streptomyces griseus.
Blakeslea trispora is a mould and member of the division Zygomycota. This species has been well studied for its ability to produce carotenoids, particularly, β-carotene and lycopene. β-carotene is a vitamin A precursor and both of β-carotene and lycopene play a significant role in the inhibition of oxidative stress. Blakeslea trispora is commonly isolated from soil samples throughout the Southern United States and Southern Asia. B. trispora is a pathogen of tropical plants. In vivo pathogenicity testing using animal models suggests this fungus is not a cause of animal or human disease.
In enzymology, beta-carotene 15,15'-dioxygenase, (EC 1.13.11.63) is an enzyme with systematic name beta-carotene:oxygen 15,15'-dioxygenase (bond-cleaving). In human it is encoded by the BCDO2 gene. This enzyme catalyses the following chemical reaction
Retinal pigment epithelium-specific 65 kDa protein, also known as retinoid isomerohydrolase, is an enzyme of the vertebrate visual cycle that is encoded in humans by the RPE65 gene. RPE65 is expressed in the retinal pigment epithelium and is responsible for the conversion of all-trans-retinyl esters to 11-cis-retinol during phototransduction. 11-cis-retinol is then used in visual pigment regeneration in photoreceptor cells. RPE65 belongs to the carotenoid oxygenase family of enzymes.
Damascenones are a series of closely related chemical compounds that are components of a variety of essential oils. The damascenones belong to a family of chemicals known as rose ketones, which also includes damascones and ionones. beta-Damascenone is a major contributor to the aroma of roses, despite its very low concentration, and is an important fragrance chemical used in perfumery.
Phytoene synthase is a transferase enzyme involved in the biosynthesis of carotenoids. It catalyzes the conversion of geranylgeranyl pyrophosphate to phytoene. This enzyme catalyses the following chemical reaction
ζ-Carotene (zeta-carotene) is a carotenoid. It is different from α-carotene and β-carotene because it is acyclic. ζ-Carotene is similar in structure to lycopene, but has an additional 4 hydrogen atoms. ζ-carotene can be used as an intermediate in forming β-carotene. A dehydrogenation reaction converts ζ-carotene into lycopene, which then can be transformed into β-carotene through the action of lycopene beta-cyclase. ζ-Carotene is a natural product found in Lonicera japonica and Rhodospirillum rubrum.
15-cis-phytoene desaturases, are enzymes involved in the carotenoid biosynthesis in plants and cyanobacteria. Phytoene desaturases are membrane-bound enzymes localized in plastids and introduce two double bonds into their colorless substrate phytoene by dehydrogenation and isomerize two additional double bonds. This reaction starts a biochemical pathway involving three further enzymes called the poly-cis pathway and leads to the red colored lycopene. The homologous phytoene desaturase found in bacteria and fungi (CrtI) converts phytoene directly to lycopene by an all-trans pathway.
9,9'-dicis-zeta-carotene desaturase is an enzyme with systematic name 9,9'-dicis-zeta-corotene:quinone oxidoreductase. This enzyme catalyses the following chemical reaction
Phytoene desaturase (neurosporene-forming) is an enzyme with systematic name 15-cis-phytoene:acceptor oxidoreductase (neurosporene-forming). This enzyme catalyses the following chemical reaction
Phytoene desaturase (3,4-didehydrolycopene-forming) is an enzyme with systematic name 15-cis-phytoene:acceptor oxidoreductase (3,4-didehydrolycopene-forming). This enzyme catalyses the following chemical reaction
Phytoene desaturase (lycopene-forming) are enzymes found in archaea, bacteria and fungi that are involved in carotenoid biosynthesis. They catalyze the conversion of colorless 15-cis-phytoene into a bright red lycopene in a biochemical pathway called the poly-trans pathway. The same process in plants and cyanobacteria utilizes four separate enzymes in a poly-cis pathway.
ζ-Carotene isomerase is an enzyme with systematic name 9,15,9'-tricis-zeta-carotene cis-trans-isomerase. This enzyme catalyses the following chemical reaction
Beta-carotene isomerase is an enzyme with systematic name beta-carotene 9-cis-all-trans isomerase. This enzyme catalyses the following chemical reaction
Lycopene β-cyclase is an enzyme with systematic name carotenoid beta-end group lyase (decyclizing). This enzyme catalyses the following chemical reaction
