Despite the drug's infamy, cocaine is chemically similar to a host of anesthetics and stimulants used legally every day. Understanding how cocaine is made in the coca plant might therefore lead to new anesthetic drugs without the addictive qualities, the study authors say.

"Plants can't run away, so they have to be the planet's best chemists to survive," said study co-author John D'Auria, a biochemist at the Max Planck Institute for Chemical Ecology in Germany.

"They make chemicals other organisms simply cannot make, including cocaine."

(Related: "Cocaine Addiction Uses Same Brain Paths as Salt Cravings.")

But to maximize a chemical's benefits to humans, he said, "we need to have some idea how the plants are making it. If you understand the biochemistry,