Oleanane

Oleananes is the name given to chemicals produced by many flowering plants, which have a suppressing effect on some insect pest organismss. Technically they are oleanone triterpanes.

They are considered a key marker differentiating flowering plants from other life, and have been used in the effort to study their evolution which is as of yet poorly documented in the fossil record.

These compounds appear to have been shared by a group of plants called gigantopterids, which lived twice as long ago as the oldest known flower fossils. They may have been close relatives of the flowering plants, moving the divergence of the flowering plant lineage back to more than 250 million years ago. However oleanane is also recorded from ferns.