Biology:Tetrahydrocannabinol

From HandWiki
Short description: Chemical compound
Tetrahydrocannabinol
INN: dronabinol
THC.svg
Delta-9-tetrahydrocannabinol-from-tosylate-xtal-3D-balls.png
Clinical data
Trade namesMarinol, Syndros
Other names(6aR,10aR)-delta-9-Tetrahydrocannabinol; (−)-trans9-Tetrahydrocannabinol; THC
License data
Pregnancy
category
  • US: C (Risk not ruled out)
Dependence
liability
Low – moderate (8–10%)[1]
Addiction
liability
Relatively low: 9%
Routes of
administration
Oral, local/topical, transdermal, sublingual, inhaled
Drug classCannabinoid
ATC code
Legal status
Legal status
  • AU: Unscheduled: ACT, Schedule 8 (Controlled Drug)
  • BR: Dronabinol: A3; THC <30mg/ml: A3; others: F2 (prohibited).
  • CA: Unscheduled
  • DE: Dronabinol: Anlage III, Δ9-THC: II, other isomers and their stereochemical variants: I. (Does not apply to THC as part of cannabis, which is regulated separately, see Cannabis (drug))
  • UK: Class B
  • US: Schedule II as Syndros, and Schedule III as Marinol[2]
  • UN: Psychotropic Schedule I /II
Pharmacokinetic data
Bioavailability10–35% (inhalation), 6–20% (oral)[3]
Protein binding97–99%[3][4][5]
MetabolismMostly hepatic by CYP2C[3]
Elimination half-life1.6–59 h,[3] 25–36 h (orally administered dronabinol)
Excretion65–80% (feces), 20–35% (urine) as acid metabolites[3]
Identifiers
CAS Number
PubChem CID
IUPHAR/BPS
DrugBank
ChemSpider
UNII
KEGG
ChEBI
ChEMBL
Chemical and physical data
FormulaC21H30O2
Molar mass314.469 g·mol−1
3D model (JSmol)
Specific rotation−152° (ethanol)
Boiling point155–157°C @ 0.05mmHg,[6] 157–160°C @ 0.05mmHg[7]
Solubility in water0.0028 mg/mL (23 °C)[8]
 ☒N☑Y (what is this?)  (verify)

Tetrahydrocannabinol (THC) is the principal psychoactive constituent of cannabis and one of at least 113 total cannabinoids identified on the plant. Although the chemical formula for THC (C21H30O2) describes multiple isomers,[9] the term THC usually refers to the delta-9-THC isomer with chemical name (−)-trans9-tetrahydrocannabinol. THC is a terpenoid found in cannabis[10] and, like many pharmacologically active phytochemicals, it is assumed to be involved in the plant's evolutionary adaptation against insect predation, ultraviolet light, and environmental stress.[11][12][13] THC was first discovered and isolated by Israeli chemist Raphael Mechoulam in Israel in 1964. It was found that, when smoked, THC is absorbed into the bloodstream and travels to the brain, attaching itself to endocannabinoid receptors located in the cerebral cortex, cerebellum, and basal ganglia. These are the parts of the brain responsible for thinking, memory, pleasure, coordination and movement.

THC, along with its double bond isomers and their stereoisomers,[14] is one of only three cannabinoids scheduled by the UN Convention on Psychotropic Substances (the other two are dimethylheptylpyran and parahexyl). It was listed under Schedule I in 1971, but reclassified to Schedule II in 1991 following a recommendation from the WHO. Based on subsequent studies, the WHO has recommended the reclassification to the less-stringent Schedule III.[15] Cannabis as a plant is scheduled by the Single Convention on Narcotic Drugs (Schedule I and IV). It is specifically still listed under Schedule I by US federal law[16] under the Controlled Substances Act for having "no accepted medical use" and "lack of accepted safety". However, dronabinol, a pharmaceutical form of THC, has been approved by the FDA as an appetite stimulant for people with AIDS and an antiemetic for people receiving chemotherapy under the trade names Marinol and Syndros.[17]

Medical uses

Medical uses of cannabis has a long history.[18] THC is an active ingredient in nabiximols, a specific extract of Cannabis that was approved as a botanical drug in the United Kingdom in 2010 as a mouth spray for people with multiple sclerosis to alleviate neuropathic pain, spasticity, overactive bladder, and other symptoms.[19][20] Nabiximols (as Sativex) is available as a prescription drug in Canada.[21] In 2021, nabiximols was approved for medical use in Ukraine .[22]

As of 2023, 38 states, four territories, and the District of Columbia in the United States allow medical use of cannabis (in which THC is the primary psychoactive component), with the exception of Georgia, Idaho, Indiana, Iowa, Kansas, Nebraska, North Carolina, South Carolina, Tennessee, Texas, Wisconsin, and Wyoming.[23] As of 2022, the U.S. federal government maintains cannabis as a schedule I controlled substance, while dronabinol is classified as Schedule III in capsule form (Marinol) and Schedule II in liquid oral form (Syndros).[24][25]

Overdose

The median lethal dose of THC in humans is not fully known as there is conflicting evidence. A 1972 study gave up to 9000 mg/kg of THC to dogs and monkeys without any lethal effects. Some rats died within 72 hours after a dose of up to 3600 mg/kg.[26] A 2014 study gave the median lethal dose in humans at 30 mg/kg (2.1 grams THC for a person who weighs 70 kg; 154 lb; 11 stone), observing cardiovascular death in otherwise healthy subjects.[27] A different 1972 study gave the median lethal dose for intravenous THC in mice and rats at 30–40 mg/kg.[28]

Interactions

Formal drug–drug interaction studies with THC have not been conducted and are limited.[29][30] The elimination half-life of the barbiturate pentobarbital has been found to increase by 4 hours when concomitantly administered with oral THC.[29]

Pharmacology

Mechanism of action

The actions of Delta-9-THC result from its partial agonist activity at the cannabinoid receptor CB1 (Ki = 40.7 nM[31]), located mainly in the central nervous system, and the CB2 receptor (Ki = 36 nM[31]), mainly expressed in cells of the immune system.[32] The psychoactive effects of THC are primarily mediated by the activation of (mostly G-coupled) cannabinoid receptors, which result in a decrease in the concentration of the second messenger molecule cAMP through inhibition of adenylate cyclase.[33] The presence of these specialized cannabinoid receptors in the brain led researchers to the discovery of endocannabinoids, such as anandamide and 2-arachidonoyl glyceride (2-AG).[citation needed]

THC is a lipophilic molecule[34] and may bind non-specifically to a variety of entities in the brain and body, such as adipose tissue (fat).[35][36] THC, as well as other cannabinoids that contain a phenol group, possess mild antioxidant activity sufficient to protect neurons against oxidative stress, such as that produced by glutamate-induced excitotoxicity.[32]

THC targets receptors in a manner far less selective than endocannabinoid molecules released during retrograde signaling, as the drug has a relatively low cannabinoid receptor affinity. THC is also limited in its efficacy compared to other cannabinoids due to its partial agonistic activity, as THC appears to result in greater downregulation of cannabinoid receptors than endocannabinoids. Furthermore, in populations of low cannabinoid receptor density, THC may even act to antagonize endogenous agonists that possess greater receptor efficacy. However while THC's pharmacodynamic tolerance may limit the maximal effects of certain drugs, evidence suggests that this tolerance mitigates undesirable effects, thus enhancing the drug's therapeutic window.[37]

Recently, it has been shown that THC is also a partial autotaxin inhibitor, with an apparent IC50 of 407 ± 67 nM for the ATX-gamma isoform.[38] THC was also co-crystallized with autotaxin, deciphering the binding interface of the complex. These results might explain some of the effects of THC on inflammation and neurological diseases, since autotaxin is responsible of LPA generation, a key lipid mediator involved in numerous diseases and physiological processes. However, clinical trials need to be performed in order to assess the importance of ATX inhibition by THC during medicinal cannabis consumption.

Pharmacokinetics

Absorption

With oral administration of a single dose, THC is almost completely absorbed by the gastrointestinal tract.[29] However, due to first-pass metabolism in the liver and the high lipid solubility of THC, only about 5 to 20% reaches circulation.[3][29] Following oral administration, concentrations of THC and its major active metabolite 11-hydroxy-THC (11-OH-THC) peak after 0.5 to 4 hours, with median time to peak of 1.0 to 2.5 hours at different doses.[29][3] In some cases, peak levels may not occur for as long as 6 hours.[3] Concentrations of THC and 11-hydroxy-THC in the circulation are approximately equal with oral administration.[29] There is a slight increase in dose proportionality in terms of peak and area-under-the-curve levels of THC with increasing oral doses over a range of 2.5 to 10 mg.[29] A high-fat meal delays time to peak concentrations of oral THC by 4 hours on average and increases area-under-the-curve exposure by 2.9-fold, but peak concentrations are not significantly altered.[29] A high-fat meal additionally increases absorption of THC via the lymphatic system and allows it to bypass first-pass metabolism.[39] Consequently, a high-fat meal increases levels of 11-hydroxy-THC by only 25% and most of the increase in bioavailability is due to increased levels of THC.[39]

The bioavailability of THC when smoking or inhaling is approximately 25%, with a range of 2% to 56% (although most commonly between 10 and 35%).[30][40][3] The large range and marked variability between individuals is due to variation in factors including product matrix, ignition temperature, and inhalational dynamics (e.g., number, duration, and intervals of inhalations, breath hold time, depth and volume of inhalations, size of inhaled particles, deposition site in the lungs).[30][40] THC is detectable within seconds with inhalation and peak levels of THC occur after 3 to 10 minutes.[3][40] Smoking or inhaling THC results in greater blood levels of THC and its metabolites and a much faster onset of action than oral administration of THC.[30][40] Inhalation of THC bypasses the first-pass metabolism that occurs with oral administration.[30] The bioavailability of THC with inhalation is increased in heavy users.[3]

Transdermal administration of THC is limited by its extreme water insolubility.[30] Efficient skin transport can only be obtained with permeation enhancement.[30] Transdermal administration of THC, as with inhalation, avoids the first-pass metabolism that occurs with oral administration.[30]

The bioavailability of THC with rectal administration as a suppository was reported to be about twice that of its oral bioavailability in a small pharmacokinetic study of two individuals with spasticity.[3]

Distribution

The volume of distribution of THC is large and is approximately 10 L/kg (range 4–14 L/kg), which is due to its high lipid solubility.[29][30][40] The plasma protein binding of THC and its metabolites is approximately 95 to 99%, with THC bound mainly to lipoproteins and to a lesser extent albumin.[29][3] THC is rapidly distributed into well-vascularized organs such as lung, heart, brain, and liver, and is subsequently equilibrated into less vascularized tissue.[30][40] It is extensively distributed into and sequestered by fat tissue due to its high lipid solubility, from which it is slowly released.[39][30][40] THC is able to cross the placenta and is excreted in human breast milk.[30][3]

Metabolism

The metabolism of THC occurs mainly in the liver by cytochrome P450 enzymes CYP2C9, CYP2C19, and CYP3A4.[41][42] CYP2C9 and CYP3A4 are the primary enzymes involving in metabolizing THC.[29] Pharmacogenomic research has found that oral THC exposure is 2- to 3-fold greater in people with genetic variants associated with reduced CYP2C9 function.[29] When taken orally, THC undergoes extensive first-pass metabolism in the liver, primarily via hydroxylation.[29] The principal active metabolite of THC is 11-hydroxy-THC (11-OH-THC), which is formed by CYP2C9 and is psychoactive similarly to THC.[39][30][29] This metabolite is further oxidized to 11-nor-9-carboxy-THC (THC-COOH). In animals, more than 100 metabolites of THC could be identified, but 11-OH-THC and THC-COOH are the predominant metabolites.[39][43]

Elimination

More than 55% of THC is excreted in the feces and approximately 20% in the urine. The main metabolite in urine is the ester of glucuronic acid and 11-OH-THC and free THC-COOH. In the feces, mainly 11-OH-THC was detected.[44]

Estimates of the elimination half-life of THC are variable.[30] THC was reported to have a fast initial half-life of 6 minutes and a long terminal half-life of 22 hours in a population pharmacokinetic study.[30][40] Conversely, the Food and Drug Administration label for dronabinol reports an initial half-life of 4 hours and a terminal half-life of 25 to 36 hours.[29] Many studies report an elimination half-life of THC in the range of 20 to 30 hours.[3] 11-Hydroxy-THC appears to have a similar terminal half-life to that of THC, for instance 12 to 36 hours relative to 25 to 36 hours in one study.[3] The elimination half-life of THC is longer in heavy users.[30] This may be due to slow redistribution from deep compartments such as fatty tissues, where THC accumulates with regular use.[30]

Chemistry

Discovery and structure identification

Cannabidiol was isolated and identified from Cannabis sativa in 1940,[45] and THC was isolated and its structure elucidated by synthesis in 1964.[46][47]

Solubility

As with many aromatic terpenoids, THC has a very low solubility in water, but good solubility in lipids and most organic solvents, specifically hydrocarbons and alcohols.[8]

Total synthesis

A total synthesis of the compound was reported in 1965; that procedure called for the intramolecular alkyl lithium attack on a starting carbonyl to form the fused rings, and a tosyl chloride mediated formation of the ether.[48][third-party source needed]

Biosynthesis

In the Cannabis plant, THC occurs mainly as tetrahydrocannabinolic acid (THCA, 2-COOH-THC). Geranyl pyrophosphate and olivetolic acid react, catalysed by an enzyme to produce cannabigerolic acid,[49] which is cyclized by the enzyme THC acid synthase to give THCA. Over time, or when heated, THCA is decarboxylated, producing THC. The pathway for THCA biosynthesis is similar to that which produces the bitter acid humulone in hops.[50][51] It can also be produced in genetically modified yeast.[52]

Biosynthesis of THC

History

THC was first isolated and elucidated in 1964 by Yechiel Gaoni and Raphael Mechoulam at the Weizmann Institute of Science in Israel.[46][53][54]

In 2003, the World Health Organization Expert Committee on Drug Dependence recommended transferring THC to Schedule IV of the convention, citing its medical uses and low abuse and addiction potential.[55]

Society and culture

Comparisons with medical cannabis

Female cannabis plants contain at least 113 cannabinoids,[56] including cannabidiol (CBD), thought to be the major anticonvulsant that helps people with multiple sclerosis,[57] and cannabichromene (CBC), an anti-inflammatory which may contribute to the pain-killing effect of cannabis.[58]

Drug testing

Main page: Biology:Cannabis drug testing

THC and its 11-OH-THC and THC-COOH metabolites can be detected and quantified in blood, urine, hair, oral fluid or sweat using a combination of immunoassay and chromatographic techniques as part of a drug use testing program or in a forensic investigation.[59][60][61] There is ongoing research to create devices capable of detecting THC in breath.[62][63]

Regulation in Canada

As of October 2018 when recreational use of cannabis was legalized in Canada, some 220 dietary supplements and 19 veterinary health products containing not more than 10 parts per million of THC extract were approved with general health claims for treating minor conditions.[21]

Research

The status of THC as an illegal drug in most countries imposes restrictions on research material supply and funding, such as in the United States where the National Institute on Drug Abuse and Drug Enforcement Administration continue to control the sole federally-legal source of cannabis for researchers. Despite an August 2016 announcement that licenses would be provided to growers for supplies of medical marijuana, no such licenses were ever issued, despite dozens of applications.[64] Although cannabis is legalized for medical uses in more than half of the states of the United States, no products have been approved for federal commerce by the Food and Drug Administration, a status that limits cultivation, manufacture, distribution, clinical research, and therapeutic applications.[65]

In April 2014, the American Academy of Neurology found evidence supporting the effectiveness of the cannabis extracts in treating certain symptoms of multiple sclerosis and pain, but there was insufficient evidence to determine effectiveness for treating several other neurological diseases.[66] A 2015 review confirmed that medical marijuana was effective for treating spasticity and chronic pain, but caused numerous short-lasting adverse events, such as dizziness.[67]

Multiple sclerosis symptoms

  • Spasticity. Based on the results of 3 high quality trials and 5 of lower quality, oral cannabis extract was rated as effective, and THC as probably effective, for improving people's subjective experience of spasticity. Oral cannabis extract and THC both were rated as possibly effective for improving objective measures of spasticity.[66][67]
  • Centrally mediated pain and painful spasms. Based on the results of 4 high quality trials and 4 low quality trials, oral cannabis extract was rated as effective, and THC as probably effective in treating central pain and painful spasms.[66]
  • Bladder dysfunction. Based on a single high quality study, oral cannabis extract and THC were rated as probably ineffective for controlling bladder complaints in multiple sclerosis[66]

Neurodegenerative disorders

  • Huntington disease. No reliable conclusion could be drawn regarding the effectiveness of THC or oral cannabis extract in treating the symptoms of Huntington disease as the available trials were too small to reliably detect any difference[66]
  • Parkinson's disease. Based on a single study, oral CBD extract was rated probably ineffective in treating levodopa-induced dyskinesia in Parkinson's disease.[66]
  • Alzheimer's disease. A 2009 Cochrane Review found insufficient evidence to conclude whether cannabis products have any utility in the treatment of Alzheimer's disease.[68]

Other neurological disorders

  • Tourette syndrome. The available data was determined to be insufficient to allow reliable conclusions to be drawn regarding the effectiveness of oral cannabis extract or THC in controlling tics.[66]
  • Cervical dystonia. Insufficient data was available to assess the effectiveness of oral cannabis extract of THC in treating cervical dystonia.[66]

Potential for toxicity

Preliminary research indicates that prolonged exposure to high doses of THC may interfere with chromosomal stability, which may be hereditary as a factor affecting cell instability and cancer risk. The carcinogenicity of THC in the studied populations of so-called "heavy users" remains dubious due to various confounding variables, most significantly concurrent tobacco use.[69]

See also


References

  1. "The Facts On Marijuana". NADCP. December 2010. https://dwicourts.org/sites/default/files/nadcp/Facts%20on%20Marijuana%20-%20NADCP_0.pdf. "Based upon several nationwide epidemiological studies, marijuana's dependence liability has been reliably determined to be 8 to 10 percent." 
  2. "Marinol". https://www.fda.gov/ohrms/dockets/dockets/05n0479/05N-0479-emc0004-04.pdf. 
  3. 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 3.12 3.13 3.14 3.15 "Pharmacokinetics and pharmacodynamics of cannabinoids". Clinical Pharmacokinetics 42 (4): 327–60. 2003. doi:10.2165/00003088-200342040-00003. PMID 12648025. 
  4. The Royal Pharmaceutical Society of Great Britain (2006). "Cannabis". Martindale: The Complete Drug Reference: Single User (35th ed.). Pharmaceutical Press. ISBN 978-0-85369-703-9. [page needed]
  5. "Tetrahydrocannabinol – Compound Summary". National Center for Biotechnology Information. PubChem. https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=16078&loc=ec_rcs#x332. "Dronabinol has a large apparent volume of distribution, approximately 10 L/kg, because of its lipid solubility. The plasma protein binding of dronabinol and its metabolites is approximately 97%." 
  6. "Isolation, Structure, and Partial Synthesis of an Active Constituent of Hashish". Journal of the American Chemical Society 86 (8): 1646–47. April 1964. doi:10.1021/ja01062a046. 
  7. "Structure of Cannabidiol. XII. Isomerization to Tetrahydrocannabinols". Journal of the American Chemical Society 63 (8): 2209–13. August 1941. doi:10.1021/ja01853a052. 
  8. 8.0 8.1 "Physiochemical properties, solubility, and protein binding of delta9-tetrahydrocannabinol". Journal of Pharmaceutical Sciences 63 (7): 1056–64. July 1974. doi:10.1002/jps.2600630705. PMID 4853640. 
  9. "THC Chemistry by Alexander Shulgin - January 21, 1995". http://www.druglibrary.org/olsen/dea/shulgin.html. 
  10. "Why do plants produce so many terpenoid compounds?". The New Phytologist 220 (3): 692–702. November 2018. doi:10.1111/nph.14178. PMID 27604856. 
  11. "Chemical ecology of Cannabis". Journal of the International Hemp Association 2 (29): 32–37. 1994. http://www.internationalhempassociation.org/jiha/iha01201.html. Retrieved 2017-12-09. 
  12. "Possible role of ultraviolet radiation in evolution of Cannabis chemotypes". Economic Botany 37 (4): 396–405. 1983. doi:10.1007/BF02904200. 
  13. "UV-B radiation effects on photosynthesis, growth and cannabinoid production of two Cannabis sativa chemotypes". Photochemistry and Photobiology 46 (2): 201–06. August 1987. doi:10.1111/j.1751-1097.1987.tb04757.x. PMID 3628508. https://zenodo.org/record/1230776. Retrieved 2019-07-04. 
  14. "Cannabis through the looking glass: chemo- and enantio-selective separation of phytocannabinoids by enantioselective ultra high performance supercritical fluid chromatography". Chemical Communications 53 (91): 12262–65. November 2017. doi:10.1039/C7CC06999E. PMID 29072720. 
  15. "The UN Drug Control Conventions". 8 October 2015. https://www.tni.org/en/publication/the-un-drug-control-conventions#box3. 
  16. "Drug Schedules; Schedule 1". US Drug Enforcement Administration, Department of Justice. 1 December 2017. https://www.dea.gov/drug-information/drug-scheduling. 
  17. "Marinol (Dronabinol)". US Food and Drug Administration. September 2004. https://www.accessdata.fda.gov/drugsatfda_docs/label/2005/018651s021lbl.pdf. 
  18. Atakan Z. (2012). "Cannabis, a complex plant: different compounds and different effects on individuals.". Therapeutic Advances in Psychopharmacology. 2 (6): 241–254. doi:10.1177/2045125312457586. PMID 23983983. 
  19. "Sativex Oromucosal Spray – Summary of Product Characteristics" (in en). UK Electronic Medicines Compendium. March 2015. http://www.medicines.org.uk/emc/medicine/23262. 
  20. Multiple Sclerosis Trust. October 2014 Sativex (nabiximols) – factsheet
  21. 21.0 21.1 "Health products containing cannabis or for use with cannabis: Guidance for the Cannabis Act, the Food and Drugs Act, and related regulations". Government of Canada. 11 July 2018. https://www.canada.ca/en/health-canada/services/drugs-health-products/drug-products/applications-submissions/guidance-documents/guidance-cannabis-act-food-and-drugs-act-related-regulations/document.html. 
  22. "В Україні легалізували використання медичного канабісу, але не всього" (in Ukrainian). УП.Життя (UP.Life). 9 April 2021. https://life.pravda.com.ua/health/2021/04/9/244505/. 
  23. "State Medical Cannabis Laws". National Conference of State Legislatures. 3 February 2022. http://www.ncsl.org/research/health/state-medical-marijuana-laws.aspx. 
  24. "Drug scheduling: Marijuana (Cannabis)". US Department of Justice, Drug Enforcement Administration. 2022. https://www.dea.gov/drug-information/drug-scheduling. 
  25. "Controlled Substances". https://www.deadiversion.usdoj.gov/schedules/orangebook/c_cs_alpha.pdf. 
  26. "Comparison of acute oral toxicity of cannabinoids in rats, dogs and monkeys". Toxicology and Applied Pharmacology 25 (3): 363–72. July 1973. doi:10.1016/0041-008X(73)90310-4. PMID 4199474. "In dogs and monkeys, single oral doses of Δ9-THC and Δ8-THC between 3000 and 9000/mg/kg were nonlethal.". 
  27. "Sudden unexpected death under acute influence of cannabis". Forensic Science International 237: e11–e13. April 2014. doi:10.1016/j.forsciint.2014.02.001. PMID 24598271. 
  28. "UNODC - Bulletin on Narcotics - 1972 Issue 2 - 002" (in en). United Nations: Office on Drugs and Crime: 11–27. 1 January 1972. https://www.unodc.org/unodc/en/data-and-analysis/bulletin/bulletin_1972-01-01_2_page003.html. Retrieved 2022-12-11. 
  29. 29.00 29.01 29.02 29.03 29.04 29.05 29.06 29.07 29.08 29.09 29.10 29.11 29.12 29.13 29.14 https://www.accessdata.fda.gov/drugsatfda_docs/label/2023/018651s033lbl.pdf
  30. 30.00 30.01 30.02 30.03 30.04 30.05 30.06 30.07 30.08 30.09 30.10 30.11 30.12 30.13 30.14 30.15 30.16 "The pharmacokinetics and the pharmacodynamics of cannabinoids". Br J Clin Pharmacol 84 (11): 2477–2482. November 2018. doi:10.1111/bcp.13710. PMID 30001569. 
  31. 31.0 31.1 "The Structure–Function Relationships of Classical Cannabinoids: CB1/CB2 Modulation". Perspectives in Medicinal Chemistry 8: 17–39. 28 June 2016. doi:10.4137/PMC.S32171. PMID 27398024. 
  32. 32.0 32.1 "The pharmacology of cannabinoid receptors and their ligands: an overview". International Journal of Obesity 30 (Suppl 1): S13–S18. April 2006. doi:10.1038/sj.ijo.0803272. PMID 16570099. 
  33. "The neurobiology and evolution of cannabinoid signalling". Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences 356 (1407): 381–408. March 2001. doi:10.1098/rstb.2000.0787. PMID 11316486. 
  34. "Hydroxylation and further oxidation of delta9-tetrahydrocannabinol by alkane-degrading bacteria". Applied and Environmental Microbiology 75 (22): 7135–41. November 2009. doi:10.1128/AEM.01277-09. PMID 19767471. Bibcode2009ApEnM..75.7135R. "Δ9-THC and many of its derivatives are highly lipophilic and poorly water soluble. Calculations of the n-octanol-water partition coefficient (Ko/w) of Δ9-THC at neutral pH vary between 6,000, using the shake flask method, and 9.44 × 106, by reverse-phase high-performance liquid chromatography estimation.". 
  35. "Pharmacology and effects of cannabis: a brief review". The British Journal of Psychiatry 178 (2): 101–06. February 2001. doi:10.1192/bjp.178.2.101. PMID 11157422. "Because they are extremely lipid soluble, cannabinoids accumulate in fatty tissues, reaching peak concentrations in 4–5 days. They are then slowly released back into other body compartments, including the brain. ... Within the brain, THC and other cannabinoids are differentially distributed. High concentrations are reached in neocortical, limbic, sensory and motor areas.". 
  36. "Human cannabinoid pharmacokinetics". Chemistry & Biodiversity 4 (8): 1770–804. August 2007. doi:10.1002/cbdv.200790152. PMID 17712819. "THC is highly lipophilic and initially taken up by tissues that are highly perfused, such as the lung, heart, brain, and liver.". 
  37. "The diverse CB1 and CB2 receptor pharmacology of three plant cannabinoids: delta9-tetrahydrocannabinol, cannabidiol and delta9-tetrahydrocannabivarin". British Journal of Pharmacology 153 (2): 199–215. January 2008. doi:10.1038/sj.bjp.0707442. PMID 17828291. 
  38. "Linking medicinal cannabis to autotaxin-lysophosphatidic acid signaling". Life Science Alliance 6 (2): e202201595. February 2023. doi:10.26508/lsa.202201595. PMID 36623871. 
  39. 39.0 39.1 39.2 39.3 39.4 "Review of delta-8-tetrahydrocannabinol (Δ8 -THC): Comparative pharmacology with Δ9 -THC". Br J Pharmacol 179 (15): 3915–3933. August 2022. doi:10.1111/bph.15865. PMID 35523678. 
  40. 40.0 40.1 40.2 40.3 40.4 40.5 40.6 40.7 "Cannabis and Cannabinoids: Kinetics and Interactions". Am J Med 132 (11): 1266–1270. November 2019. doi:10.1016/j.amjmed.2019.05.017. PMID 31152723. 
  41. "The Potential for Pharmacokinetic Interactions Between Cannabis Products and Conventional Medications". Journal of Clinical Psychopharmacology 39 (5): 462–71. 2019. doi:10.1097/JCP.0000000000001089. PMID 31433338. 
  42. "Cytochrome P450 enzymes involved in the metabolism of tetrahydrocannabinols and cannabinol by human hepatic microsomes". Life Sciences 80 (15): 1415–19. March 2007. doi:10.1016/j.lfs.2006.12.032. PMID 17303175. 
  43. "Simultaneous quantification of major cannabinoids and metabolites in human urine and plasma by HPLC-MS/MS and enzyme-alkaline hydrolysis". Drug Testing and Analysis 9 (4): 626–33. April 2017. doi:10.1002/dta.1998. PMID 27341312. https://figshare.com/articles/journal_contribution/5028359. Retrieved 2022-12-02. 
  44. "Pharmacokinetics and Metabolism of the Plant Cannabinoids, Δ9-Tetrahydrocannabinol, Cannabidiol and Cannabinol". Handbook of Experimental Pharmacology 168 (168): 657–90. 2005. doi:10.1007/3-540-26573-2_23. ISBN 978-3-540-22565-2. PMID 16596792. 
  45. "Structure of Cannabidiol, a Product Isolated from the Marihuana Extract of Minnesota Wild Hemp.". Journal of the American Chemical Society 62: 196–200. 1940. doi:10.1021/ja01858a058. 
  46. 46.0 46.1 "Isolation, structure and partial synthesis of an active constituent of hashish". Journal of the American Chemical Society 86 (8): 1646–47. 1964. doi:10.1021/ja01062a046. 
  47. "Marihuana chemistry". Science 168 (3936): 1159–66. June 1970. doi:10.1126/science.168.3936.1159. PMID 4910003. Bibcode1970Sci...168.1159M. 
  48. "A Total Synthesis of Dl-Delta-1-Tetrahydrocannabinol, the Active Constituent of Hashish". Journal of the American Chemical Society 87 (14): 3273–75. July 1965. doi:10.1021/ja01092a065. PMID 14324315. 
  49. "Prenylation of olivetolate by a hemp transferase yields cannabigerolic acid, the precursor of tetrahydrocannabinol". FEBS Letters 427 (2): 283–85. May 1998. doi:10.1016/S0014-5793(98)00450-5. PMID 9607329. 
  50. "Identification of candidate genes affecting Delta9-tetrahydrocannabinol biosynthesis in Cannabis sativa". Journal of Experimental Botany 60 (13): 3715–26. 2009. doi:10.1093/jxb/erp210. PMID 19581347. 
  51. "The tetrahydrocannabinol and tetrahydrocannabinolic acid content of cannabis products". The Journal of Pharmacy and Pharmacology 33 (6): 369–72. June 1981. doi:10.1111/j.2042-7158.1981.tb13806.x. PMID 6115009. 
  52. "Complete biosynthesis of cannabinoids and their unnatural analogues in yeast". Nature 567 (7746): 123–26. March 2019. doi:10.1038/s41586-019-0978-9. PMID 30814733. Bibcode2019Natur.567..123L. https://backend.orbit.dtu.dk/ws/files/240436196/qt3fn1m6p5_noSplash_be06dd7b6fdfa004bec17ec4fed2cabd.pdf. Retrieved 2021-12-30. 
  53. "Interview with the winner of the first ECNP Lifetime Achievement Award: Raphael Mechoulam, Israel". February 2007. http://matters.ecnp.nl/number11/interview2.shtml. 
  54. "Cannabinoids: A Secret History". Chemical Heritage Newsmagazine 25 (2). 2007. http://chemicalheritage.org/pubs/ch-v25n2-articles/feature_cannabinoids.html. 
  55. "WHO Expert Committee on Drug Dependence". World Health Organization. https://www.who.int/substance_abuse/right_committee/en/index.html. 
  56. "Evolution of the Cannabinoid and Terpene Content during the Growth of Cannabis sativa Plants from Different Chemotypes". Journal of Natural Products 79 (2): 324–31. February 2016. doi:10.1021/acs.jnatprod.5b00949. PMID 26836472. https://figshare.com/articles/journal_contribution/5028338. Retrieved 2022-12-02. 
  57. "Sedative activity of cannabis in relation to its delta'-trans-tetrahydrocannabinol and cannabidiol content". British Journal of Pharmacology 72 (4): 649–56. April 1981. doi:10.1111/j.1476-5381.1981.tb09145.x. PMID 6269680. 
  58. "Molecular Targets of the Phytocannabinoids: A Complex Picture". Phytocannabinoids. Progress in the Chemistry of Organic Natural Products. 103. 2017. pp. 103–31. doi:10.1007/978-3-319-45541-9_4. ISBN 978-3-319-45539-6. 
  59. "Delta9-tetrahydrocannabinol (THC), 11-hydroxy-THC, and 11-nor-9-carboxy-THC plasma pharmacokinetics during and after continuous high-dose oral THC". Clinical Chemistry 55 (12): 2180–89. December 2009. doi:10.1373/clinchem.2008.122119. PMID 19833841. 
  60. "Concentrations of delta9-tetrahydrocannabinol and 11-nor-9-carboxytetrahydrocannabinol in blood and urine after passive exposure to Cannabis smoke in a coffee shop". Journal of Analytical Toxicology 34 (4): 196–203. May 2010. doi:10.1093/jat/34.4.196. PMID 20465865. 
  61. Disposition of Toxic Drugs and Chemicals in Man (9th ed.). Seal Beach, CA: Biomedical Publications. 2011. pp. 1644–48. 
  62. "Testing drivers for cannabis is hard. Here's why". CNN Business. January 2, 2020. https://www.cnn.com/2020/01/02/business/cannabis-breathalyzers-are-coming-to-market/index.html. 
  63. "Topical review on monitoring tetrahydrocannabinol in breath". Journal of Breath Research 14 (3): 034002. May 2020. doi:10.1088/1752-7163/ab6229. PMID 31842004. Bibcode2020JBR....14c4002M. 
  64. "Medical Marijuana". Multidisciplinary Association for Psychedelic Studies. http://www.maps.org/research/mmj/. 
  65. "The legal status of cannabis (marijuana) and cannabidiol (CBD) under U.S. law". Epilepsy & Behavior 70 (Pt B): 288–91. May 2017. doi:10.1016/j.yebeh.2016.11.021. PMID 28169144. http://www.epilepsybehavior.com/article/S1525-5050(16)30585-6/fulltext. Retrieved 2018-01-26. 
  66. 66.0 66.1 66.2 66.3 66.4 66.5 66.6 66.7 "Systematic review: efficacy and safety of medical marijuana in selected neurologic disorders: report of the Guideline Development Subcommittee of the American Academy of Neurology". Neurology 82 (17): 1556–63. April 2014. doi:10.1212/WNL.0000000000000363. PMID 24778283. 
  67. 67.0 67.1 "Cannabinoids for Medical Use: A Systematic Review and Meta-analysis". JAMA 313 (24): 2456–73. 2015. doi:10.1001/jama.2015.6358. PMID 26103030. 
  68. "Cannabinoids for the treatment of dementia". The Cochrane Database of Systematic Reviews 2009 (2): CD007204. April 2009. doi:10.1002/14651858.CD007204.pub2. PMID 19370677. 
  69. "Chromothripsis and epigenomics complete causality criteria for cannabis- and addiction-connected carcinogenicity, congenital toxicity and heritable genotoxicity". Mutation Research 789: 15–25. July 2016. doi:10.1016/j.mrfmmm.2016.05.002. PMID 27208973. 

External links