ô-Carotene (delta-carotene) or õ,ÃÂ-carotene is a form of carotene with an õ-ring at one end, and the other uncyclized, labelled à(psi). It is an intermediate synthesis product in some photosynthetic plants between lycopene and ñ-carotene (ò,õ-carotene) or õ-carotene (õ,õ-carotene). ô-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.