Δ-Carotene Explained

δ-Carotene (delta-carotene) or ε,ψ-carotene is a form of carotene with an ε-ring at one end, and the other uncyclized, labelled ψ (psi). It is an intermediate synthesis product in some photosynthetic plants between lycopene and α-carotene (β,ε-carotene) or ε-carotene (ε,ε-carotene).^[1] δ-Carotene is fat soluble. Delta-carotene contains an alpha-ionone instead of a beta-ionone ring;^[2] 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.^[3]

Notes and References

1. Cunningham FX, Gantt E . One ring or two? Determination of ring number in carotenoids by lycopene epsilon-cyclases . Proceedings of the National Academy of Sciences of the United States of America . 98 . 5 . 2905–10 . February 2001 . 11226339 . 30238 . 10.1073/pnas.051618398 . free .
2. Tomes ML . Delta-carotene in the tomato . Genetics . 62 . 4 . 769–80 . August 1969 . 10.1093/genetics/62.4.769 . 17248458 . 1212314 .
3. Tomes ML . The competitive effect of the Beta- and delta-carotene genes on alpha- or Beta-ionone ring formation in the tomato . Genetics . 56 . 2 . 227–32 . June 1967 . 10.1093/genetics/56.2.227 . 17248383 . 1211498 .