Substances in cannabis guide

Cannabis is a chemically very complex plant. As you know, not only the most familiar cannabinoids are found in it, but over 500 different naturally occurring substances and compounds can be found in it. These include, for example, cannabinoids, flavonoids, terpenoids and omega fatty acids. Our guide will take you through the most important ones – their chemistry, where they occur, how they smell and how they were discovered.

CBD, THC, CBG, CBN, CBC, CBDa, CBDv, THCa, THCv

Cannabinoid acids, polyphenols, flavonoids, cannaflavins, terpenes, terpenoids

CANNABINOIDS

Cannabinoids are a group of chemical compounds that are typical of the cannabis plant. Chemically, most of them belong to the terpenophenols – molecules composed of a terpene part and a phenolic part. Over 100 species have been discovered so far. The most important are THC, CBD, CBN and CBC.

In the plant, cannabinoids are produced in the trichomes – tiny resin glands that cover the flowers and, to a lesser extent, the leaves. The resin protects the plant from UV radiation, drying out and pests.

How are cannabinoids formed and where are they found?

Cannabinoids are not exclusive to cannabis. Similar compounds have also been found in a few other plants and in liverworts. Depending on their origin, they are divided into three groups:

Cannabinoids formed in the cannabis plant (phytocannabinoids)
Similar compounds formed in other plants
Synthetic cannabinoids produced in laboratories

Biosynthesis of cannabinoids

Almost all major cannabinoids originate from a single compound, cannabigerolic acid (CBGa). It is formed from olivetolic acid and geranyl pyrophosphate. Plant enzymes then convert CBGa into THCa, CBDa or CBCa. Which acid prevails depends on the genetics of the given variety – that is why some varieties are rich in THC and others in CBD.

PHYTOCANNABINOIDS

Phytocannabinoids are cannabinoids of plant origin. There are around 100 known phytocannabinoids found in cannabis. The main phytocannabinoids are CBD and THC. In the living plant, they occur mainly in their acidic form, which changes into the neutral form when heated or as the plant material ages.

SYNTHETIC CANNABINOIDS

In addition to natural production, cannabinoids can also be produced in laboratories. These artificially created compounds mimic the structure of naturally occurring cannabinoids, but often differ from them considerably. They have nothing in common with the hemp plant itself.

Now we will look together at some specific cannabinoids and their properties.

CBD

CBD, or cannabidiol, is probably the most well-known cannabinoid compound derived mainly from the Cannabis sativa plant. After THC, it is the second most abundant cannabinoid in cannabis, and in many hemp varieties it is the dominant one.

Cannabidiol was first isolated in 1940 by the American chemist Roger Adams, and its exact chemical structure was described in 1963 by Raphael Mechoulam's team. Its molecular formula is C21H30O2 – the same as that of THC; the two molecules differ only in the arrangement of their atoms.

In the plant, CBD is formed from its acidic precursor CBDa. Pure CBD is a white crystalline substance, which is why it is also sold as an isolate in the form of crystals. It is used in the production of oils, cosmetics and other hemp products.

THC

When you say marijuana, the first substance most people think of is THC. THC, or delta-9-tetrahydrocannabinol, is the best-known cannabinoid of cannabis. It was first isolated and described in 1964 by Raphael Mechoulam and Yechiel Gaoni in Israel.

In the living plant, THC is present almost exclusively as the acid THCa. It is only through heat or long-term storage that THCa loses its carboxyl group and changes into THC. The THC content of individual varieties varies widely and is determined by their genetics; industrial hemp contains only small amounts of it.

THC is an oily substance that is practically insoluble in water but dissolves well in fats and alcohol. When exposed to oxygen and light, it gradually oxidises to CBN.

CBDV

CBDV, or cannabidivarin, is in the class of cannabinoids. CBDV is structurally very similar to CBD – it differs only by a shorter side chain (propyl instead of pentyl).

Although CBDV was discovered more than 50 years ago, it has still not been sufficiently studied, as like most other cannabinoids it has long been overshadowed by THC.

CBDV occurs in higher amounts mainly in varieties originating from Asia and Africa, especially in landrace indica strains. Breeders have recently also created varieties with an increased CBDV content.

CBC

CBC is one of the lesser-known cannabinoids, but that doesn't detract from its interest. Cannabichromene was discovered more than 50 years ago (in 1966) and has the same origin as THC and CBD (it comes from CBGa).

In the plant, CBC is formed from its acidic precursor CBCa. It is more abundant in young plants and in some tropical varieties. When exposed to light, it can change into cannabicyclol (CBL).

CBN

A lesser known and also less studied cannabinoid is CBN. Cannabinol was the very first cannabinoid ever isolated – at the end of the 19th century – and its structure was determined in the 1930s.

CBN is formed by the degradation of THC. If THC is exposed to oxygen, light and heat, it oxidises and gives rise to CBN. That is why old or improperly stored cannabis contains more CBN and less THC. The CBN content is therefore also used as an indicator of the age of the plant material.

CBG

CBG is another very important phytocannabinoid found in cannabis plants. It was first isolated in 1964.

Although the plant itself has been grown for thousands of years, CBG is a fairly new thing and has not yet been subjected to such in-depth study. All research is in its infancy and everything we know so far is just the tip of the iceberg.

Its acidic form CBGa is the "mother" of the other cannabinoids, because THCa, CBDa and CBCa are formed from it. Most of it is therefore converted into other compounds as the plant matures.

CBG is quite hard to "find". Cannabis is harvested specifically for CBD and THC, the two most well-known substances. Harvest time plays a big role in the amount of CBG content, as it decreases as the plant matures. That is why breeders have created special CBG-rich varieties.

THCV

THCV, or tetrahydrocannabivarin, is a relatively unknown compound. It is much less 'attractive' than CBD, THC or CBG, but it still deserves our attention.

THCV was discovered in 1973. Chemically, it is a close relative of THC – it differs from it only by a shorter side chain with three carbon atoms instead of five. Cannabinoids with this shorter chain are called varins.

THCV is formed from its acidic precursor THCVa, which in turn originates from CBGVa. It occurs in higher amounts mainly in sativa landrace varieties from Africa and Asia, for example in strains from South Africa.

Cannabinoid acids

What is the difference between cannabinoids and cannabinoid acids? Probably the most significant difference is that there is a carboxyl group (-COOH) in the structure of a cannabinoid acid. When heated, this group is split off as carbon dioxide and the acid changes into a neutral cannabinoid. This process is called decarboxylation.

As a rule, these acids are the cornerstones of the cannabinoids themselves, because the plant produces cannabinoids almost exclusively in their acidic form. The neutral forms are only formed later, through heat, light or ageing.

CBGa (Cannabigerolic acid)

CBGa is an essential compound found in cannabis. CBGa is located at the top of the cascade reaction and gives rise to three main cannabinoid lineages: THCa, CBDa and CBCa. These acids become THC, CBD or CBC. It can also break down into CBG.

Although this acid was discovered fifty years ago, it has not yet been subjected to sufficient research. Most experiments have focused on its conversion into THCa and CBDa.

The enzymes that convert CBGa are called synthases (THCa synthase, CBDa synthase and CBCa synthase). The genes for these enzymes largely determine the cannabinoid profile of each variety.

THCA (tetrahydrocannabinolic acid)

THC and THCa are almost identical in their chemical formula, but THCa carries an additional carboxyl group. This difference significantly changes the properties of the molecule.

THCa is the main cannabinoid in fresh flowers of THC-rich varieties. When the flowers are dried, THCa slowly changes into THC, and when heated, the conversion is very fast.

Like many other compounds, THCa is derived from CBGa. As the plant matures, CBGa is converted into one of three cannabinoid precursors: THCa, CBDa and CBCa.

CBDA (Cannabidiolic Acid)

CBDa is transformed by heat and time into the familiar CBD. CBDa is formed, like THCa and CBCa, from CBGa. CBGa (cannabigerolic acid) is transformed into these three main compounds. Today, it is often contained in raw (unheated) hemp extracts and oils.

Is CBDa important?

CBDa is the main cannabinoid in fresh hemp varieties rich in CBD. It was first isolated in 1955. Because it is not very stable, it gradually converts to CBD during drying and storage, and very quickly when heated. Products that are not heated during production therefore contain a higher share of CBDa.

CBCa (cannabichromenic acid)

CBCa owes its origins to CBGa. CBCa occurs in very low quantities in the plant, so scientists have not yet studied it in much detail.

Once CBCa undergoes decarboxylation, it becomes CBC. And if CBCa is exposed to UV light, it is converted to CBLa (cannabicyclolic acid). CBCa has still not been subjected to the necessary amount of research, but like many other cannabinoid acids, it has a promising future ahead of it.

CBGVa (cannabigerovarinic acid)

During the biosynthesis process, CBGVa gives us THCVa, CBDVa and CBCVa. It plays the same role for the varins as CBGa does for the common cannabinoids. CBGVa is formed when the plant uses divarinic acid instead of olivetolic acid. It has not yet received much attention, so its research is in its very early stages.

THCVa (tetrahydrocannabivarinic acid)

As we mentioned just a few lines above, THCVa is created from CBGVa. THCVa, like CBDVa, is classified as a propylcannabinoid. These are substances that occur in really small, almost minute quantities in the plant, but of course there can be exceptions.

THCVa has also not been sufficiently studied. When heated, it changes into THCV. For the time being, work is being done to separate THCVa from the other compounds to describe its properties in more detail.

CBDVa (cannabidivarinic acid)

CBDVa is the precursor to CBDV. This substance has also received little attention but is expected to receive more attention from scientists in the future. It occurs mainly in varieties with a higher CBDV content.

CBCVa (cannabichromevarinic acid)

CBCVa is the acidic precursor of cannabichromevarin (CBCV). It belongs to the varins and is structurally related to CBCa.

CBCVa has still not been sufficiently studied. Because of its structure, it is expected to behave chemically in a similar way to the other varins.

Polyphenols

Polyphenols are a large group of plant compounds whose molecules contain several phenolic groups. They are found in fruits, vegetables, tea, coffee, cocoa and of course in cannabis.

Polyphenols form a huge group that includes flavonoids. We also include catechins, tannins, isoflavones, etc.

The role of polyphenols in plants

In plants, polyphenols play a number of roles. They protect the plant from UV radiation and pests, give colour to flowers and fruits, and contribute to their taste – for example, the bitter and astringent taste of tea or red wine is caused by tannins.

Polyphenols are antioxidants in the chemical sense – they easily react with free radicals and oxygen. That is why they also play a role in the stability and colour of food.

They are naturally contained in many plant-based foods.

Flavonoids

Flavonoids are organic chemical compounds found in fruits, vegetables and herbs, so they are a common part of our diet.

Flavonoids make up a small part of the dry weight of cannabis. Scientists have already identified around twenty different flavonoids in cannabis. But some types are only found in cannabis and are called cannaflavins (more below). Like terpenes (more below), flavonoids also contribute to the colour, aroma and taste of the plant.

What is the importance of flavonoids in cannabis?

The word flavonoid comes from the Latin flavus = yellow. One of the main functions of flavonoids is to pigment the plant, thereby attracting pollinators. In addition to pigmentation, flavonoids are also responsible for protecting plants from various elements such as UV radiation, moulds and pests.

The aroma of cannabis is often attributed to terpenes alone, but flavonoids also play an important role. It is only through the interaction between terpenes and flavonoids that different aromas and flavours are created.

Flavonoids and colours

Anthocyanins, a group of flavonoids, are responsible for the purple, blue and red colours of some cannabis varieties. Their formation is influenced by genetics and also by cooler night temperatures at the end of flowering.

Flavonoids can be found, for example, in grapefruit, blueberries, parsley, garlic, red wine and chocolate with a high cocoa content. Flavonoids can also be found in chlorella, spirulina or young barley.

Cannaflavins

Cannaflavins are flavonoids found in cannabis. And why are they so interesting and have a separate name? Because these substances are only found in the cannabis plant. And that's what makes them really special.

Cannaflavins A, B, C

Cannaflavins A and B were first described in 1985 by the British researcher Marilyn Barrett; cannaflavin C was identified later. Chemically, they are prenylated flavones related to apigenin and luteolin.

In addition to cannaflavins, cannabis also contains other flavonoids and related compounds that are common in the plant kingdom:

Quercetin – a yellow pigment found in onions, apples, capers and tea.
Isovitexin – a flavone glycoside also found in passion flower and buckwheat.
Apigenin – a flavone found in chamomile, parsley and celery.
β-sitosterol – a plant sterol that is common in vegetable oils, nuts and seeds.
Luteolin – a yellow flavone found in celery, thyme, peppers and the herb weld, which was once used to dye fabrics.

Other flavonoids in cannabis include Orientin, Catechins and Vitexin.

Terpenes

Terpenes are a very important part of not only cannabis, but also other plants, flowers and herbs. They bring a wonderful aroma. These substances are largely responsible for the smell and taste that the plants possess. In addition, they also protect the plants from pests and attract pollinators. Chemically, terpenes are made up of isoprene units with five carbon atoms.

Terpenes in cannabis

Up to 200 terpenes are found in cannabis in various proportions. However, only dozens of these are considered significant, as they occur in the highest amounts. The ratio of individual terpenes creates the characteristic aroma of each variety.

The best known terpenes include:

MYRCENE

Myrcene is the most abundant terpene in cannabis. It is found in hops, thyme, basil, mango and many other plants. It has an earthy, musky and slightly fruity aroma reminiscent of cloves. Myrcene is a monoterpene with a boiling point of around 167 °C.

CARYOPHYLLENE

Caryophyllene is the second most abundant terpene. It is quite pungent and peppery, as it is primarily found in black pepper. However, it is also found in cinnamon, oregano, cloves and thyme. It is a sesquiterpene, and thanks to its spicy aroma it is often used in the food and perfume industries.

LIMONENE

Limonene is probably the best known of all terpenes. As its name suggests, it has a citrus aroma. It is found in large amounts in the peel of lemons, oranges and other citrus fruits. Limonene is widely used in perfumes, cleaning products, cosmetics and as a flavouring in food.

PINENE

Pinene is a very aromatic terpene and is found not only in cannabis. Its name comes from the word pine, and it has a typical pine tree smell. It occurs in two forms, alpha-pinene and beta-pinene, and is the most common terpene in nature. It is also found in rosemary, basil and parsley.

TERPINOLENE

Terpinolene is found predominantly in fragrant plants and therefore has a fresh herbal floral scent with a unique citrus aroma. It occurs, for example, in nutmeg, lilac, tea tree or apples. Very often used as an ingredient in soaps, perfumes and cosmetics.

HUMULENE

Humulene is most commonly found in hops, cloves, basil and, of course, cannabis. It has a very earthy and woody aroma with spicy undertones. It is responsible for the typical "hoppy" aroma of beer. Chemically, it is an isomer of caryophyllene.

Other terpenes in cannabis

In smaller amounts, cannabis also contains a number of other terpenes:

Linalool – a floral terpene with a lavender scent, also found in coriander, birch and many flowers. It is one of the most commonly used fragrance substances in perfumery.
Ocimene – a sweet, herbal and woody terpene found in mint, parsley, orchids and kumquats.
Eucalyptol (cineole) – a terpene with a fresh, camphor-like scent typical of eucalyptus. It is also found in rosemary, sage and bay leaves.
Bisabolol – a delicate floral terpene known from chamomile, often used in cosmetics.
Geraniol – a terpene with a rose-like scent, found in geraniums and roses.

Where can terpenes be found?

Terpenes are all around us. Whether you go for a walk in the woods, in the city or stay at home – you will always come into contact with terpenes. They give the scent to conifers, citrus fruits, herbs and spices, and they are the main component of essential oils.

Terpenes are produced commercially from many plant sources. They are used to flavour food and drinks, in perfumes, cosmetics and household products.

Terpenes versus cannabinoids

Are cannabinoids related to terpenes? Yes – both groups of compounds are formed in the same trichomes and share some of the building blocks. Cannabinoids are formed by joining a terpene part (geranyl pyrophosphate) with a phenolic part (olivetolic acid). Together, they create the unique chemical profile and aroma of each variety.

Terpenoids

Terpenoids belong to the class of terpenes and the two terms are often used interchangeably. Terpenoids are more complex than terpenes in terms of molecular structure, because they contain additional functional groups, most often oxygen. Some terpenoids are found at higher levels in dried plants after a period of oxidation, while others are found in fresh plants. These molecules fall into two main categories: monoterpenoids and sesquiterpenoids.

Terpenoids are among the largest groups of natural compounds – tens of thousands of them are known. They play a role in food, perfumes, cosmetics, vitamins (e.g. vitamin A) and plant pigments such as carotenoids.

Like terpenes, many terpenoids are contained in the strong resin produced in the heads of trichomes. They play a vital role in ensuring plant survival, helping to eliminate pest attacks and resist fluctuating environmental factors.