ChEBI: Axerophthene is a diterpene that is cyclohexene substituted by a (1Z,3E,5E,7E)-3,7-dimethylnona-1,3,5,7-tetraen-1-yl group at position 2 and by methyl groups at positions 1,3 and 3. It is the parent hydrocarbon on which Vitamin A and other retinoids are based. It is a diterpene and a polyene.