Salvinorin A

Salvinorin A
Systematic (IUPAC) name
methyl (2S,4aR,6aR,7R,9S,10aS,10bR)-9-(acetyloxy)-2-(furan-3-yl)-6a,10b-dimethyl-4,10-dioxododecahydro-2H-benzo[f]isochromene-7-carboxylate
Clinical data
Pregnancy cat.  ?
Legal status Uncontrolled (though Salvia divinorum is controlled in some parts of the world, such as in certain states in the US)
Routes Buccal/Sublingual, Smoked
Identifiers
CAS number 83729-01-5 N
ATC code None
PubChem CID 128563
IUPHAR ligand 1666
ChemSpider 113947 Y
ChEMBL CHEMBL445332 Y
Chemical data
Formula C23H28O8 
Mol. mass 432.46 g/mol
SMILES eMolecules & PubChem
Physical data
Melt. point 242-244–238-240 °C (-165–-162 °F)
Boiling point 760.2 °C (1400 °F)
 N(what is this?)  (verify)

Salvinorin A is the main active psychotropic molecule in Salvia divinorum, a Mexican plant which has a long history of use as an entheogen by indigenous Mazatec shamans. Salvinorin A is considered a dissociative exhibiting atypically psychedelic effects.

It is structurally distinct from other naturally occurring hallucinogens (such as DMT, psilocybin, and mescaline) because it contains no nitrogen atoms, hence it is not an alkaloid (and cannot be rendered as a salt) but a terpenoid.

Salvinorin A can produce psychoactive experiences in humans with a typical duration of action being several minutes to an hour or so, depending on the method of ingestion.[1]

Salvinorin A is found with several other structurally related salvinorins. Salvinorin is a trans-neoclerodane diterpenoid. It acts as a kappa opioid receptor agonist and is the first known compound acting on this receptor that is not an alkaloid. Its pharmacological mechanism was elucidated in the laboratory of Bryan L. Roth.

Contents

History

Salvinorin A was first described and named in 1982 by Alfredo Ortega and colleagues in Mexico. They used a combination of spectroscopy and x-ray crystallography to determine the chemical structure of the compound, which was shown to have a bicyclic diterpene structure.[2] Around the same time, Julian Valdés independently isolated the molecule as part of his PhD research, published in 1983.[3] Valdés named the chemical divinorum, and also isolated an analog that he named divinorum B. The naming was subsequently corrected to salvinorin A and B after the work was published in 1984.[4] Valdés later isolated salvinorin C.[5]

Pharmacology

Salvinorin A is a trans-neoclerodane diterpenoid with the chemical formula C23H28O8.[6] Unlike other known opioid-receptor ligands, salvinorin A is not an alkaloid—it does not contain a basic nitrogen atom.[7] Salvinorin A has no action at the 5-HT2A serotonin receptor, the principal molecular target responsible for the actions of 'classical' psychedelics such as LSD and mescaline.[7]

Potency and selectivity

Salvinorin A "is the most potent naturally occurring hallucinogen."[7] It is active at doses as low as 200 µg.[6][8][9] Synthetic chemicals, such as LSD (active at 20–30 µg doses), can be more potent.[10] Research has shown that salvinorin A is a potent κ-opioid receptor agonist.[6] It has a high affinity for the receptor, indicated by the low dissociation constant of 1.0 nanomolar (nM).[11] It has been reported that the effects of salvinorin A in mice are blocked by κ-opioid receptor antagonists.[12] This makes it unlikely that another mechanism contributes independently to the compound's observed effects in mice. However, salvinorin A has recently been found to act as an even more potent D2 receptor partial agonist, with an affinity of 5–10 nM, an intrinsic activity of 40–60%, and an EC50 of 50–90 nM, which is several-fold higher than its EC50 of 235 nM for the κ-opioid receptor.[13] This suggests that the D2 receptor may also play an important role in its effects.[13]

Salvinorin A is unique in that it is the only naturally occurring substance known to induce a visionary state via this mode of action; there are synthetic kappa-opioid agonists, (e.g. enadoline, ketazocine, pentazocine and relatives), which show similar hallucinatory and dissociative effects.

Salvinorin A's potency should not be confused with toxicity. Mice chronically given dosages "many times that of what humans are exposed to"[14] did not show signs of organ damage. However, "further studies should be done on blood pressure effects" and "Pulse pressure did appear to increase with salvinorin A exposure twenty and forty minutes after exposure, however, this increase was not statistically significant" (note that the data shows an increase in pulse pressure that was roughly 1.5–2 times the control group's).[15]

Effect on intestinal motility

Salvinorin A is capable of inhibiting excess intestinal motility (e.g. diarrhea), through a combination of k-opioid and cannabinoid (mainly CB1 receptor) receptors in inflamed but not normal gut in vivo. The mechanism of action for salvinorin A on ileal tissue has been described as 'prejunctional', as it was able to modify electrically induced contractions, but not those of exogenous acetylcholine.[16] A pharmacologically important aspect of the contraction-reducing properties of ingested salvinorin A on gut tissue is that it is only pharmacologically active on inflamed and not normal tissue, thus reducing possible side-effects.[17]

Solubility

Salvinorin A is soluble in organic solvents such as ethanol and acetone, but not especially so in water.

Detection in urine

Humans who smoked 580 μg of the pure drug had urine salvinorin A concentrations of 2.4–10.9 µg/L during the first hour, but the levels fell below the detection limit by 1.5 hours after smoking. Analytical measurements may be performed using gas or liquid chromatography-mass spectrometry.[18]

Associated compounds

Many other terpenoids have been isolated from Salvia divinorum, including other salvinorins and related compounds named divinatorins and salvinicins. None of these compounds have shown significant (sub-micromolar) affinity at the kappa-opioid receptor, and there is no evidence that they contribute to the plant's psychoactivity.[19][20]

Synthesis

Biosynthesis

The biogenic origin of salvinorin A synthesis has been elucidated using nuclear magnetic resonance and ESI-MS analysis of incorporated precursors labeled with stable isotopes of carbon (Carbon-13 13C) and hydrogen (Deuterium 2H). It "is biosynthesized via the 1-deoxy-d-xylulose-5-phosphate pathway," rather than the classic mevalonate pathway typical for plant terpenoids.[21]

Similar to many plant-derived psychoactive compounds, salvinorin A is excreted via peltate glandular trichomes, which reside external to the epidermis.[22][23]

Chemical synthesis

A total asymmetric synthesis of salvinorin A, which relies on a transannular Michael reaction cascade to construct the ring system, was achieved in 2007 by Evans and co-workers in 4.5% overall yield over 30 steps.[24] More recently, a synthesis was published by a Japanese group, requiring 24 steps to yield salvinorin A in 0.15% yield.[25]

An approach to the trans-decalin ring system of salvinorin A has been described by Forsyth (et al.) utilizing an intramolecular Diels-Alder reaction/Tsuji allylation strategy.[26]

An attempt at the synthesis of salvinorin A has also been published by a group at RMIT University, adopting a convergent synthesis of a functionalized cyclohexanone with a α,β-unsaturated lactone.[27]

Other salvinorins

Salvinorin A is one of several structurally related salvinorins found in the Salvia divinorum plant. Salvinorin A can be synthesized from the inactive salvinorin B by acetylation. The des-acetylated analog salvinorin B is devoid of human activity. It was speculated that salvinorin C might be even more potent than salvinorin A, but human tests and receptor binding assays could not confirm this [Ref?]. Salvinorin A seems to be the only active naturally occurring salvinorin.[20]

Salvinorins A - F
Name Structure R1 R2 Activity
Salvinorin A -OCOCH3 − active
Salvinorin B -OH − inactive
Salvinorin C -OCOCH3 -OCOCH3 unknown
Salvinorin D -OH -OCOCH3 inactive
Salvinorin E -OCOCH3 -OH inactive
Salvinorin F -H -OH unknown

The newly discovered salvinorin J is most closely related to salvinorin E in structure, with a C-17 secondary alcohol instead of a ketone group.[28]

Semi-synthetic analogues

Research on salvinorin derivatives has produced a number of semi-synthetic compounds, several of which can be conveniently made from salvinorin B. Most derivatives are selective kappa opioid agonists as with salvinorin A, although some are even more potent, with the most potent compound 2-ethoxymethyl salvinorin B being 10x stronger than salvinorin  A. A few derivatives such as herkinorin have reduced kappa opioid action and instead act as mu opioid agonists.[29][30][31][32][33][34][35][36]

Pharmaceutical action

Results from a small study by an assistant professor at the University of Iowa indicate that it may have potential as an analgesic and as a therapeutic tool for treating drug addictions.[37][38] κ-opioid agonists have very marked effects on all types of addiction including alcohol, cocaine, and opiate abuse.

Legality

See also: Legal status of Salvia divinorum

Salvinorin A is sometimes regulated together with its host, Salvia divinorum, due to its psychoactive and analgesic effects.

See also

References

  1. ^ Roth BL, Baner K, Westkaemper R, Siebert D, Rice KC, Steinberg S, Ernsberger P, Rothman RB (2002). "Salvinorin A: a potent naturally occurring nonnitrogenous κ opioid selective agonist". Proceedings of the National Academy of Sciences U.S.A. 99 (18): 11934–9. doi:10.1073/pnas.182234399. PMC 129372. PMID 12192085. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=129372. 
  2. ^ Ortega A, Blount JF, Manchard PD. (1982). "Salvinorin, a new trans-neoclerodane diterpene from Salvia divinorum (Labiatae)". Journal of the Chemical Society, Perkins Transactions I: 2505–8. doi:http://dx.doi.org/10.1039/P19820002505. 
  3. ^ Valdés LJJ III (1983). The pharmacognosy of Salvia divinorum (Epling and Jativa-M): An Investigation of Ska Maria Pastora (Mexico) (PhD thesis). University of Michigan. http://proquest.umi.com/pqdlink?Ver=1&Exp=10-19-2016&FMT=7&DID=750217621&RQT=309&attempt=1&cfc=1. 
  4. ^ Valdés III LJJ, Butler WM, Hatfield GM, Paul AG, Koreeda M. (1984). "Divinorin A, a psychotropic terpenoid, and divinorin B from the hallucinogenic Mexican mint Salvia divinorum". Journal of Organic Chemistry 49: 4716–20. doi:http://dx.doi.org/10.1021/jo00198a026. 
  5. ^ Valdés III LJJ, Chang HM, Visger DC, Koreeda M. (2001). "Salvinorin C, a new neoclerodane diterpene from a bioactive fraction of the hallucinogenic Mexican mint Salvia divinorum". Organic Letters 3: 3935–7. doi:http://dx.doi.org/10.1021/ol016820d. 
  6. ^ a b c Prisinzano TE (2005). "Psychopharmacology of the hallucinogenic sage Salvia divinorum". Life Sciences 78 (5): 527–31. doi:10.1016/j.lfs.2005.09.008. PMID 16213533. 
  7. ^ a b c Harding WW, Schmidt M, Tidgewell K, Kannan P, Holden KG, Gilmour B, Navarro H, Rothman RB, Prisinzano TE (2006). "Synthetic studies of neoclerodane diterpenes from Salvia divinorum: semisynthesis of salvinicins A and B and other chemical transformations of salvinorin A". Journal of Natural Products 69 (1): 107–12. doi:10.1021/np050398i. PMC 2544632. PMID 16441078. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2544632. 
  8. ^ Imanshahidi M, Hosseinzadeh H (2006). "The pharmacological effects of Salvia species on the central nervous system". Phytotherapy Research 20 (6): 427–37. doi:10.1002/ptr.1898. PMID 16619340. "However, when smoked (in a manner similar to free base cocaine), the compound is effective in doses of 200–500 μg and produces visions that last from 30 minutes to an hour or two, while doses over 2 mg are effective for much longer. At doses greater than 500 μg the subject is often no longer aware of their surroundings and may enter an uncontrollable delirium. This compound is the most potent naturally occurring hallucinogen thus far isolated." 
  9. ^ Marushia, Robin (2002). "Salvia divinorum: The Botany, Ethnobotany, Biochemistry and Future of a Mexican Mint". Ethnobotany. Archived from the original on October 7, 2007. http://web.archive.org/web/20071007165306/http://www.cyjack.com/Cognition/Salvia.pdf. Retrieved 2006-12-23. 
  10. ^ Greiner T, Burch NR, Edelberg R (1958). "Psychopathology and psychophysiology of minimal LSD-25 dosage; a preliminary dosage-response spectrum". AMA Archives of Neurology and Psychiatry 79 (2): 208–10. PMID 13497365. 
  11. ^ Lee D, Ma Z, Liu-Chen L, Wang Y, Chen Y, Carlezon W, Cohen B. (2005). "New neoclerodane diterpenoids isolated from the leaves of Salvia divinorum and their binding affinities for human K opioid receptors". Bioorganic and Medicinal Chemistry 13 (19): 5635–9. doi:10.1016/j.bmc.2005.05.054. PMID 16084728. 
  12. ^ Zhang Y, Butelman ER, Schlussman SD, Ho A, Kreek MJ (2005). "Effects of the plant-derived hallucinogen salvinorin A on basal dopamine levels in the caudate putamen and in a conditioned place aversion assay in mice: agonist actions at kappa opioid receptors". Psychopharmacology (Berl.) 179 (3): 551–8. doi:10.1007/s00213-004-2087-0. PMID 15682306. 
  13. ^ a b Seeman P, Guan HC, Hirbec H (2009). "Dopamine D2High receptors stimulated by phencyclidines, lysergic acid diethylamide, salvinorin A, and modafinil". Synapse 63 (8): 698–704. doi:10.1002/syn.20647. PMID 19391150. 
  14. ^ Note: the Mowry et al. study used the following data: 1600 μg/kg (0.0016 mg/g) daily injections for 14 days on "Swiss-Webster mice, aged 4–6 months" of unknown weight (when purchasing mice, a estimated maximum mass is 25 g). Given that the average weight for males in the United States is 190.9 lbs (according to Wikipedia), or 86,590.7834 g, and that a single gram mixture of plain leaf contains roughly 3 mg/g of Salvinorin A (according to Daniel Siebert), this translates to the mice receiving an effective dose of roughly 6,494,309 times more than a human (human doses range from minimal, 200 μg, to upwards of 24 mg, and body weights for both humans and mice vary tremendously).
  15. ^ Mowry M, Mosher M, Briner W (2003). "Acute physiologic and chronic histologic changes in rats and mice exposed to the unique hallucinogen salvinorin A" (PDF). Journal of Psychoactive Drugs 35 (3): 379–82. doi:10.1080/02791072.2003.10400021. PMID 14621136. http://www.sagewisdom.org/mowryetal.pdf. 
  16. ^ Capasso R, Borrelli F, Capasso F, Siebert DJ, Stewart DJ, Zjawiony JK, Izzo AA (2006). "The hallucinogenic herb Salvia divinorum and its active ingredient salvinorin A inhibit enteric cholinergic transmission in the guinea-pig ileum". Neurogastroenterology and Motility 18 (1): 69–75. doi:10.1111/j.1365-2982.2005.00725.x. PMID 16371085. 
  17. ^ Capasso R, Borrelli F, Zjawiony J, Kutrzeba L, Aviello G, Sarnelli G, Capasso F, Izzo AA (2007). "The hallucinogenic herb Salvia divinorum and its active ingredient salvinorin A reduce inflammation-induced hypermotility in mice". Neurogastroenterology and Motility 20 (2): 142–8. doi:10.1111/j.1365-2982.2007.00994.x. PMID 17931335. 
  18. ^ Pichini S, Abanades S, Farré M, Pellegrini M, Marchei E, Pacifici R, Torre Rde L, Zuccaro P (2005). "Quantification of the plant-derived hallucinogen salvinorin A in conventional and non-conventional biological fluids by gas chromatography/mass spectrometry after Salvia divinorum smoking". Rapid Communications in Mass Spectrometry 19 (12): 1649–1656. doi:10.1002/rcm.1970. ISSN 1097-0231. PMID 15915477. "Salvinorin A was not detected in urine samples collected from 1.5–9.5 h after smoking, probably because of a dilution effect, which yielded concentrations below the LOD obtainable with this methodology." 
  19. ^ Bigham AK, Munro TA, Rizzacasa MA, Robins-Browne RM (2003). "Divinatorins A-C, new neoclerodane diterpenoids from the controlled sage Salvia divinorum". Journal of Natural Produects 66 (9): 1242–4. doi:10.1021/np030313i. PMID 14510607. 
  20. ^ a b Munro TA, Rizzacasa MA (2003). "Salvinorins D-F, new neoclerodane diterpenoids from Salvia divinorum, and an improved method for the isolation of salvinorin A". Journal of Naturla Products 66 (5): 703–5. doi:10.1021/np0205699. PMID 12762813. 
  21. ^ Kutrzeba L, Dayan FE, Howell J, Feng J, Giner JL, Zjawiony JK (2007). "Biosynthesis of salvinorin A proceeds via the deoxyxylulose phosphate pathway". Phytochemistry 68 (14): 1872–81. doi:10.1016/j.phytochem.2007.04.034. PMC 2065853. PMID 17574635. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2065853. 
  22. ^ Siebert DJ (2004). "Localization of salvinorin A and related compounds in glandular trichomes of the psychoactive sage, Salvia divinorum". Annals of Botany 93 (6): 763–71. doi:10.1093/aob/mch089. PMID 15087301.  "A peltate glandular trichome on the abaxial leaf surface", and "The fact that most of the salvinorin content of fresh leaves can be extracted into chloroform without the solvent penetrating the epidermis indicates that these compounds are secreted externally to the epidermis."
  23. ^ Kunkle D (2007). "Leaf glandular trichome (Salvia divinorum)". Dennis Kunkel Microscopy, Inc. http://www.denniskunkel.com/DK/Plants/24071B.html. Retrieved 2011-10-14. 
  24. ^ Scheerer JR, Lawrence JF, Wang GC, Evans DA (2007). "Asymmetric synthesis of salvinorin A, a potent kappa opioid receptor agonist". Journal of the American Chemical Society 129 (29): 8968–9. doi:10.1021/ja073590a. PMID 17602636. 
  25. ^ Nozawa M, Suka Y, Hoshi T, Suzuki T, Hagiwara H (2008). "Total synthesis of the hallucinogenic neoclerodane diterpenoid salvinorin A". Organic Letters 10 (7): 1365–8. doi:10.1021/ol800101v. PMID 18311991. 
  26. ^ Burns AC, Forsyth CJ. (2008). "Intramolecular Diels−Alder/Tsuji allylation assembly of the functionalized trans-decalin of salvinorin A". Organic Letters 10 (1): 97–100. doi:10.1021/ol7024058. PMID 18062692. 
  27. ^ Lingham AR, Hügel HM, Rook TJ (2006). "Studies towards the synthesis of salvinorin A". Australian Journal of Chemistry 59 (5): 340–8. doi:10.1071/CH05338. 
  28. ^ Kutrzeba L, Ferreira Z (2009). "Salvinorins J from Salvia divinorum: mutarotation in the neoclerodane system". Journal of Natural Products 72 (7): 1361–3. doi:10.1021/np900181q. PMID 19473009. 
  29. ^ Lee DY, Karnati VV, He M, Liu-Chen LY, Kondaveti L, Ma Z, Wang Y, Chen Y, Beguin C, Carlezon WA, Cohen B (2005). "Synthesis and in vitro pharmacological studies of new C(2) modified salvinorin A analogues". Bioorganic & Medicinal Chemistry Letters 15 (16): 3744–7. doi:10.1016/j.bmcl.2005.05.048. PMID 15993589. 
  30. ^ Munro TA, Duncan KK, Xu W, Wang Y, Liu-Chen LY, Carlezon WA, Cohen BM, Béguin C (2008). "Standard protecting groups create potent and selective κ opioids: salvinorin B alkoxymethyl ethers". Bioorganic & Medicinal Chemistry 16 (3): 1279–86. doi:10.1016/j.bmc.2007.10.067. PMC 2568987. PMID 17981041. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2568987. 
  31. ^ Harding WW, Tidgewell K, Byrd N, Cobb H, Dersch CM, Butelman ER, Rothman RB, Prisinzano TE (2005). "Neoclerodane diterpenes as a novel scaffold for mu opioid receptor ligands". Journal of Medicinal Chemistry 48 (15): 4765–71. doi:dx.doi.org/10.1021/jm048963m. PMID 16033256. 
  32. ^ Tidgewell K, Harding WW, Lozama A, Cobb H, Shah K, Kannan P, Dersch CM, Parrish D, Deschamps JR, Rothman RB, Prisinzano TE (2006). "Synthesis of salvinorin A analogues as opioid receptor probes". Journal of Natural Products 69 (6): 914–8. doi:dx.doi.org/10.1021/np060094b. PMID 16792410. 
  33. ^ Holden KG, Tidgewell K, Marquam A, Rothman RB, Navarro H, Prisinzano TE (2007). "Synthetic studies of neoclerodane diterpenes from Salvia divinorum: exploration of the 1-position". Bioorganic and Medicinal Chemistry Letters 17 (22): 6111–5. doi:dx.doi.org/10.1016/j.bmcl.2007.09.050. PMID 17904842. 
  34. ^ Lee DY, He M, Liu-Chen LY, Wang Y, Li JG, Xu W, Ma Z, Carlezon WA, Cohen B (2006). "Synthesis and in vitro pharmacological studies of new C(4)-modified salvinorin A analogues". Bioorganic & Medicinal Chemistry Letters 16 (21): 5498–502. doi:10.1016/j.bmcl.2006.08.051. PMID 16945525. 
  35. ^ Béguin C, Richards MR, Li JG, Wang Y, Xu W, Liu-Chen LY, Carlezon WA, Cohen BM (2006). "Synthesis and in vitro evaluation of salvinorin A analogues: effect of configuration at C(2) and substitution at C(18)". Bioorganic & Medicinal Chemistry Letters 16 (17): 4679–85. doi:10.1016/j.bmcl.2006.05.093. PMID 16777411. 
  36. ^ A1 US 2007/0213394 A1, Beguin C, Carlezon WA, Cohen BM, He M, Lee D Y-W, Richards MR, Liu-Chen L-Y, "Salvinorin derivatives and uses thereof", published 2007-09-13, assigned to Temple University 
  37. ^ Masis 2007-02-28 (US Media)
  38. ^ Prisinzano, Tidgewell & Harding 2005.

Further reading

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