Throughout recorded history, and even before it, humans have used plants as medicine. Ancient cultures created organized lists of various plants and their medicinal properties[1]. We now know that the healing properties of plants come from the active substances within them. Over hundreds of millions of years, plants evolved to create a large number of diverse natural substances with different biological properties.
The first successful attempt to chemically isolate active substances from a plant, took place in the beginning of the 19th century (1805)[2]. Chemists isolated alkaloids, among them codeine and morphine, from the opium poppy. These breakthroughs laid down the foundation for plant-based drug discovery. Two hundred years later, more advanced technologies and modern separation techniques have made this process routine. The medicinal and psychoactive properties of cannabis have been documented since at least the second millennium BC when the plant was used by cultures stretching from the Middle East to China.
When scientists started to research the plant, they wanted to find out which substances were responsible for its psychoactive properties. This research discovered that there are actually dozens of chemicals in the plant with closely related structures and physical properties, specific to the species. These are called cannabinoids. As scientific techniques improve, researchers have been able to isolate and study more and more cannabinoids.
