All living things in nature produce a wide array of organic compounds that are not essential for living processes, but contribute to other aspects of their ecology and survival, often by mediating interactions with other organisms. These compounds are called secondary metabolites. While you might have never heard of this term, you surely used many of them in your life. Secondary metabolites produced from plants, in fact, have been used by humans for centuries as medicines, pigments, flavourings and also as recreational drugs¹. Some examples include paclitaxel, an active component of a chemotherapy drug; cocaine, a famous stimulant drug and vanillin, responsible for the vanilla flavour.

The cannabis plant is no different and produces a vast range of secondary metabolites that are responsible for its smell, taste and effects. The two major classes of secondary metabolites found in cannabis are terpenoids and cannabinoids. Terpenoids are volatile compounds (meaning that their low boiling point makes it easy for you to smell them!) that are not specific to cannabis and play a fundamental role in determining the aroma and taste of cannabis plants². Some common examples include myrcene, which is also found in hops, limonene, common in citrusy fruits such as lemon and oranges, and pinene, also found in pine needles and rosemary. As you can imagine, strains of cannabis with a similar aroma usually contain similar quantities of the same terpenoids. Cannabinoids are instead unique to this plant and are behind the psychoactive and pharmacological effects of cannabis consumption. The two major cannabinoids are tetrahydrocannabinol (THC), the primary intoxicating compound, and cannabidiol (CBD), a non-psychoactive compound that can influence the effect of THC and has been researched for its medical properties. The current understanding is that THC and CBD together largely determine the effects and potency of a specific cannabis plant³.

The endocannabinoid system (ECS, Newsletter 3), a collection of receptors and neurotransmitters present in all mammals, is responsible for mediating the response of the human body upon exposure to cannabis. Researchers are still currently investigating what processes are naturally regulated by the ECS, and how cannabinoids and other cannabis-derived compounds could be used to influence its working for therapeutic purposes⁴. As our technology advanced, so did our ability to analyse the full spectrum of chemicals present in cannabis. At least 121 different terpenoids and another 120 different cannabinoids have been discovered, numbers far bigger than the handful of compounds that dominate most research publications⁵. This stunning chemical diversity reveals the many unknowns still surrounding this plant. Several researchers have in fact pointed out that with so many compounds present in cannabis, it would be too simplistic to reduce its whole pharmacology to THC and CBD. On top of that, the wide variety of cannabis metabolites makes cannabis a relatively unexplored, valuable source of plant chemicals that researchers think will contribute to the development of new applications in the food, medicine and cosmetic industries⁶.

In the upcoming editions we will cover some of the most interesting developments of cannabis-related science. Plant genetics and taxonomy, chemical differences among strains, biomedical advancements and potential therapeutic applications, but also societal impact of legalisation and neuropsychological effect of recreational cannabis use will be some of the topics that we will dive into. Stay tuned!