δ-Carotene or ε,ψ-carotene is a form of

carotene The term carotene (also carotin, from the Latin ''carota'', "carrot") is used for many related unsaturated hydrocarbon substances having the formula C40Hx, which are synthesized by plants but in general cannot be made by animals (with the exc ...

with an ε-ring at one end, and the other uncyclized, labelled ψ (

psi Psi, PSI or Ψ may refer to: Alphabetic letters * Psi (Greek) (Ψ, ψ), the 23rd letter of the Greek alphabet * Psi (Cyrillic) (Ѱ, ѱ), letter of the early Cyrillic alphabet, adopted from Greek Arts and entertainment * "Psi" as an abbreviation ...

). It is an intermediate synthesis product in some photosynthetic plants between lycopene and

α-carotene α-Carotene is a form of carotene with a β-ionone ring at one end and an α-ionone ring at the opposite end. It is the second most common form of carotene. Human physiology In American and Chinese adults, the mean concentration of serum α-caro ...

(β,ε-carotene) or

ε-carotene ε-Carotene (''epsilon''-carotene) is a carotene The term carotene (also carotin, from the Latin ''carota'', "carrot") is used for many related unsaturated hydrocarbon substances having the formula C40Hx, which are synthesized by plants bu ...

(ε,ε-carotene). δ-Carotene is fat soluble. Delta-carotene contains an alpha-ionone instead of a beta-ionone ring; this conversion is carried out by the gene ''Del'' which shifts the position of the double bond in the ring structure. The formation delta-carotene under the presence of the ''Del'' gene is sensitive to high temperatures.

References

Carotenoids Tetraterpenes Cyclohexenes {{Biochem-stub