Beta Carotene

β-Carotene is a strongly colored red-orange pigment abundant in plants and fruits. It is an organic compound and chemically is classified as a hydrocarbon and specifically as a terpenoid (isoprenoid), reflecting its derivation from isoprene units. β-Carotene is biosynthesized from geranylgeranyl pyrophosphate.[6] It is a member of the carotenes, which are tetraterpenes, synthesized biochemically from eight isoprene units and thus having 40 carbons. Among this general class of carotenes, β-carotene is distinguished by having beta-rings at both ends of the molecule. Absorption of β-carotene is enhanced if eaten with fats, as carotenes are fat soluble.
Carotene is the substance in carrots, pumpkins and sweet potatoes that colors them orange and is the most common form of carotene in plants. When used as a food coloring, it has the E number E160a.[7]p119 The structure was deduced by Karrer et al. in 1930.[8] In nature, β-carotene is a precursor (inactive form) to vitamin A via the action of beta-carotene 15,15'-monooxygenase.[6] Isolation of β-carotene from fruits abundant in carotenoids is commonly done using column chromatography. It can also be extracted from the beta-carotene rich algae, Dunaliella Salina.[9] The separation of β-carotene from the mixture of other carotenoids is based on the polarity of a compound. β-Carotene is a non-polar compound, so it is separated with a non-polar solvent such as hexane.[10] Being highly conjugated, it is deeply colored, and as a hydrocarbon lacking functional groups, it is very lipophilic.

Source : Wikipedia