Splitting of beta-carotene in the sexual interaction of Phycomyces.

Two new 7-carbon compounds, 1 and 2, have been found in the culture medium of Phycomyces blakesleeanus. A genetic test showed that they derive from beta-carotene. These new molecules represent the missing link that proves that beta-carotene is split into fragments of 18, 15 and 7 carbon fragments, each head of a separate family of apocarotenoids.