Flavonoids are phytochemical compounds found throughout flowers, fruits, and vegetables. They’re not exclusive to cannabis and are responsible for colour pigmentations, odour, and flavour within nature’s flora.
Many are only familiar with the popular phytocannabinoids, such as tetrahydrocannabinol (THC) and cannabidiol (CBD). However, cannabis contains over 400 chemical entities, including flavonoids and terpenes.
Flavonoids are the least-researched but are way more influential than you could believe! Both terpenes and flavonoids are directly responsible for the flavour and aroma, but what separates them is the vibrant colours expressed by flavonoids.
What are flavonoids?
The name flavonoid is derived from the Latin word for yellow, flavus, referring to their colour pigmentation. They are comprised of polyphenolic compounds. The general chemical structure is a carbon skeleton made from 15 water-soluble carbon atoms, with two benzene rings connected by a three-linking carbon chain. Researchers have found over 10,000 flavonoids which have been identified and isolated.
Six main flavonoid subcategories
After identifying and isolating the individual flavonoids, they can be categorised into six significant subcategories:
The word chalcone is derived from the Latin word chalcos. These flavonoids are representative of the brown shades throughout nature. Tomatoes and apples are prime examples of fruits and vegetables with an abundant concentration of chalcones.
Flavones are one of the essential subcategories of flavonoids and are accountable for the soft shades of yellow in nature. They can commonly be found in celery, chamomile, parsley and mint.
Isoflavonoids are a very large sub-group of flavonoids and, as such, span a diverse colour spectrum from white to dark purples. In nature, soya beans and legume seeds are among the best sources of Isoflavonoids.
Flavanones are renowned for their orange hues, and in nature, high concentrations of flavanones can be found within the fruits of the citrus family. They have several potential health benefits, like their free radical-scavenging properties.
Anthoxanthins produce creamy white and yellow colours, often visible in the petals of plants, cauliflower, mushrooms or potatoes. They are occasionally used as food additives.
Anthocyanins are responsible for the darker hues of colour visible throughout flowering. Deep shades of purple to vivid reds and brilliant blues. High concentrations of anthocyanins include blueberries, plums and aubergines. They are also renowned for their analgesic, anti-inflammatory and neuroprotective properties.
These six subcategories can be broken down further, and research has shown there are over 20 flavonoids which are commonly found within cannabis and the plant kingdom. So let’s run through the top eight.
Beta-sitosterol is closely related to cholesterol and can be found in many fruits, vegetables, nuts, spices and seeds. White Haze and Tangerine Sugar are cultivars with high levels of beta-sitosterol in their flavour profiles; get ready for a slightly bitter aftertaste when vaporising.
Vitexin can be detected within the leaves of bamboo plants and passion flowers. It is known for its potential therapeutic properties, with increased medicinal research.
Renowned for its high concentrations of luteolin, the yellow petals of the Dyer’s Rocket plant have been used to produce natural yellow dyes for centuries. Luteolin is also a key ingredient in traditional Chinese medicine and can be found in carrots, peppers, and chrysanthemum flowers.
Isovitexin is an isotype of vitexin, and it occurs naturally in buckwheat, grain, flax and cannabis.
Apigenin is one of the most common flavonoids in nature and can be found in onions, parsley and celery. Its vivid yellow colour can produce cosmetics, fabric and hair dye.
Kaempferol is present in many cruciferous vegetables, including kale, sprouts and spinach. It can also be found in Northern Lights.
High concentrations of quercetin can be found in red onions, grains, blueberries, broccoli and tomatoes. It is amongst the ten most common flavonoids found in cannabis.
Orientin has been identified in the basil plant leaves and has been studied extensively for its potential therapeutic properties.
What are cannflavins?
Cannflavins are flavonoids found explicitly in cannabis and belong to the subcategory flavones. Cannflavins A and B were first isolated in 1985 by Dr Marilyn Baratt during research into anti-inflammatory compounds and have been compared with several anti-inflammatory drugs and the major cannabinoids.
Cannflavin C was identified in 2008 by Mahmoud A. ElSohly, and ongoing research into its anti-inflammatory properties continues. High levels of Cannflavins can be identified in many of the Sensi Seeds varieties, including; Skunk #1, Black Domina, and Silver Haze. There are also numerous hemp varieties bred explicitly with high levels of Cannflavins.
What do flavonoids do?
Flavonoids have multiple functions throughout nature and are found in high concentrations in plant cells. Primarily, they are essential for producing the vivid colour pigmentation needed to attract pollinating insects, but they also help to shield the plant from UV light and disease.
Flavonoids are potent antioxidants and can potentially reduce plant tissue damage. They help protect and regenerate the plant from oxidative stress caused by an imbalance in oxygen due to fluctuating environmental changes. During the Autumn and as the nights grow longer and colder, chlorophyll levels are at their lowest, and as the green hues fade, anthocyanins can be seen throughout the foliage. Similar to the final weeks of flowering, where cannabis cultivars have visible shades of purple.
However, it is not only a stress mechanism; these vivid colours help attract pollinating insects and are crucial for reproducing. This range of colours also helps protect the plant from dangerous UV lights, which can cause grievous cellular damage over long periods. Flavonoids are also responsible for the aroma, and different colour pigments influence the aroma.
When cultivating cannabis, anthocyanins express a broad range of colours throughout the cannabis flowers during flowering, and each pigment produces a distinctive aroma. An excellent example would be how the indica-dominant cultivar Purple Cookie Kush expresses purple hues throughout flowering. Whereas, the sweet and uplifting sativa Tangerine Sugar has deep shades of yellow.
In humans, flavonoids play a vital role in perceiving the plant with your senses. They work synergistically to enhance the effects of other phytocannabinoids within the endocannabinoid system, known as the entourage effect.
Cannabis flavonoids and the endocannabinoid system
The endocannabinoid system is a diverse cell-signalling network comprising endocannabinoids, CB1 and CB2 receptors and corresponding enzymes. Its principal function is to help balance and regulate essential bodily functions by maintaining homeostasis.
Endocannabinoid receptors can be found all over the body, with the highest concentration of CB1 receptors located in the central nervous system, including the neocortex, cerebellum and spinal cords. In contrast, CB2 receptors are primarily located in the peripheral immune system. Flavonoids work synergistically with these cannabinoid receptors and cannabis compounds to enhance the effects of minor phytocannabinoids.
The endocannabinoid system plays an essential part in how we react to cannabis and, subsequently, can help mediate the effects of phytocannabinoids. It can also regulate and control a myriad of functions, including; sleep, appetite, inflammatory and immune responses.
All cannabis strains contain different ratios of cannabinoid compounds, so whereas one strain might be uplifting, the other could be incredibly relaxing. It is the terpene and flavonoids within cannabis that help define your experience.
How to increase flavonoids in cannabis
If you’re looking to increase the concentration of cannabis compounds, it is crucial to make sure you have access to top-quality genetics. Always guarantee adequate ventilation, do not overwater, and give them tender love and care!
Throughout each stage of the growing cycle, cannabis plants need varying amounts of carbohydrates to ensure healthy growth, dense bud structures and heavy trichome coverage. High-quality soil can maximise nutrient uptake, and ensuring your medium has the correct pH is advised, as incorrect levels can cause nutrient deficiencies. Before harvesting, flushing helps remove the nutrient buildup in the root zone, eliminating any residue solvents in the flowers and boosting their flavour profiles.
Ensure plants are growing optimally before changing any environmental conditions or defoliating. By trimming the lower fan leaves, defoliation can help increase sugar production by directing energy to the flowering bud. However, be careful not to remove too much lower foliage, which could shunt growth.
As a natural response to environmental stress, cannabis increases the production of flavonoids to protect the plant. For example, many growers recommend decreasing the temperature during the last weeks of flowering to increase the concentration of anthocyanins. This could cause the plant to defend itself against shifting environmental conditions, subsequently increasing flavonoid production.
Pushing the boundaries
Although many scientific studies are based on the most prolific phytocannabinoids, THC and CBD, more research is still needed on minor cannabinoids, terpenes and flavonoids. With a growing interest in the bioactive properties of cannabis and increased medicinal research into the beneficial properties of flavonoids, we can hope to access their potential therapeutic values better.
Laws and regulations regarding cannabis cultivation differ from country to country. Sensi Seeds therefore strongly advises you to check your local laws and regulations. Do not act in conflict with the law.