Phytocannabinoids, also called
natural cannabinoids,
herbal cannabinoids, and
classical cannabinoids, are only known to occur naturally in significant quantity in the
cannabis plant, and are concentrated in a viscous
resin that is produced in glandular structures known as
trichomes. In addition to cannabinoids, the resin is rich in
terpenes, which are largely responsible for the odour of the cannabis plant.
Phytocannabinoids are nearly insoluble in water but are soluble in
lipids,
alcohols, and other non-polar
organic solvents. However, as
phenols they form more water-soluble
phenolate salts under strongly
alkaline conditions.
All natural cannabinoids are derived from their respective 2-
carboxylic acids (2-COOH) by
decarboxylation (catalyzed by heat, light, or
alkaline conditions).
Types
At least 66 cannabinoids have been isolated from the cannabis plant
[4] To the right the main classes of natural cannabinoids are shown. All classes derive from cannabigerol-type compounds and differ mainly in the way this precursor is cyclized.
Tetrahydrocannabinol (THC),
cannabidiol (CBD) and
cannabinol (CBN) are the most prevalent natural cannabinoids and have received the most study. Other common cannabinoids are listed below:
[edit] Tetrahydrocannabinol
Main article: Tetrahydrocannabinol
Tetrahydrocannabinol (THC) is the primary psychoactive component of the plant. Medically, it appears to ease moderate pain (
analgetic) and to be
neuroprotective. THC has approximately equal affinity for the
CB1 and CB2 receptors.
[5] Its effects are perceived to be more
cerebral.[
citation needed]
delta-9-
Tetrahydrocannabinol (Δ9-THC, THC) and
delta-8-tetrahydrocannabinol (Δ8-THC), mimic the action of
anandamide, a
neurotransmitter produced naturally in the body. The THCs produce the
high associated with
cannabis by binding to the CB1 cannabinoid receptors in the brain.
[edit] Cannabidiol
Main article: cannabidiol
Cannabidiol (CBD) is not
psychoactive, and was thought to not affect the psychoactivity of THC
[6]. However, recent evidence shows that smokers of cannabis with a high CBD/THC ratio were less likely to experience THC-induced psychosis.[
citation needed] This is supported by psychological tests, in which participants experience less intense psychotic effects when intravenous THC was coadministered with CBD (as measured with a PANSS test).
[7].}} It has been hypothesised that CBD acts as an allosteric antagonist at the CB1 receptor and thus alters the psychoactive effects of THC.[
citation needed]
Medically, it appears to relieve convulsion, inflammation, anxiety, and nausea.[
citation needed] CBD has a greater affinity for the CB2 receptor than for the CB1 receptor. It is perceived to have more effect on the body.[
citation needed]
CBD shares a
precursor with THC and is the main cannabinoid in low-THC
Cannabis strains.
[edit] Cannabinol
Main article: cannabinol
Cannabinol (CBN) is the primary product of THC degradation, and there is usually little of it in a fresh plant. CBN content increases as THC degrades in storage, and with exposure to light and air. It is only mildly psychoactive.
[edit] Tetrahydrocannabivarin
Main article: Tetrahydrocannabivarin
Tetrahydrocannabivarin (THCV) is prevalent in certain South African and Southeast Asian strains of Cannabis. It is an
antagonist of THC at CB1 receptors and attenuates the psychoactive effects of THC.
[8]
[edit] Cannabichromene
Main article: Cannabichromene
Cannabichromene (CBC) is non-psychoactive and does not affect the psychoactivity of THC
[6].