Product name: Lycopene

IUPAC name:ψ,ψ-carotene

Othernames:(6E,​8E,​10E,​12E,​14E,​16E,​18E,​20E,​22E,​24E,​26E)-​2,​6,​10,​14,​19,​23,​27,​31-​octamethyldotriaconta-​2,​6,​8,​10,​12,​14,​16,​18,​20,​22,​24,​26,​30-​tridecaene

CAS number :502-65-8  

EC number: 207-949-1

Molecular formula: C40H56

Molar mass: 536.87 g mol−1

Appearance :Deep red solid

Melting point: 172–173 °C

Solubility in water :Insoluble

Lycopene is a bright red carotene and carotenoid pigment and phytochemical found in tomatoes and other red fruits & vegetables, such as red carrots, watermelons and papayas (but not strawberries or cherries). Although lycopene is chemically a carotene, it has no vitamin A activity.

In plants, algae, and other photosynthetic organisms, lycopene is an important intermediate in the biosynthesis of many carotenoids, including beta carotene, responsible for yellow, orange or red pigmentation, photosynthesis, and photo-protection. Like all carotenoids, lycopene is a polyunsaturated hydrocarbon (an unsubstituted alkene). Structurally, it is a tetraterpene assembled from eight isoprene units, composed entirely of carbon and hydrogen, and is insoluble in water. Lycopenes eleven conjugated double bonds give it its deep red color and are responsible for its antioxidant activity. Due to its strong color and non-toxicity, lycopene is a useful food coloring.

Lycopene is not an essential nutrient for humans, but is commonly found in the diet, mainly from dishes prepared with tomato sauce. When absorbed from the stomach, lycopene is transported in the blood by various lipoproteins and accumulates in the liver, adrenal glands, and testes.

Because preliminary research has shown an inverse correlation between consumption of tomatoes and cancer risk, lycopene has been considered a potential agent for prevention of some types of cancers, particularly prostate cancer. However, this area of research and the relationship with prostate cancer have been deemed insufficient of evidence for health claim approval by the US Food and Drug Administration .

Structure and physical properties

Lycopene is a symmetrical tetraterpene assembled from 8 isoprene units. It is a member of the carotenoid family of compounds, and because it consists entirely of carbon and hydrogen, is also a carotene.Isolation procedures for lycopene were first reported in 1910, and the structure of the molecule was determined by 1931. In its natural, all-trans form, the molecule is long and straight, constrained by its system of eleven conjugated double bonds. Each double bond in this extended π electron system reduces the energy required for electrons to transition to higher energy states, allowing the molecule to absorb visible light of progressively longer wavelengths. Lycopene absorbs all but the longest wavelengths of visible light, so it appears red.

Plants and photosynthetic bacteria naturally produce all-trans lycopene, but a total of 72 geometric isomers of the molecule are sterically possible.When exposed to light or heat, lycopene can undergo isomerization to any of a number of these cis-isomers, which have a bent rather than linear shape. Different isomeres were shown to have different stabilities due to their molecular energy (highest stability: 5-cis ≥ all-trans ≥ 9-cis ≥ 13-cis > 15-cis > 7-cis > 11-cis: lowest). In the human bloodstream, various cis-isomers constitute more than 60% of the total lycopene concentration, but the biological effects of individual isomers have not been investigated.

Lycopene is insoluble in water, and can be dissolved only in organic solvents and oils. Because of its non-polarity, lycopene in food preparations will stain any sufficiently porous material, including most plastics. While a tomato stain can be fairly easily removed from fabric (provided the stain is fresh), lycopene diffuses into plastic, making it impossible to remove with hot water or detergent. If lycopene is oxidized (for example, by reacting with bleaches or acids), the double bonds between the carbon atoms will be broken; cleaving the molecule, breaking the conjugated double bond system, and eliminating the chromophore.