RCS-4

Last updated
RCS-4
RCS-4 molecular structure.png
Legal status
Legal status
Identifiers
  • 2-(4-methoxyphenyl)-1-(1-pentyl-indol-3-yl)methanone
CAS Number
ChemSpider
UNII
CompTox Dashboard (EPA)
ECHA InfoCard 100.233.383 OOjs UI icon edit-ltr-progressive.svg
Chemical and physical data
Formula C21H23NO2
Molar mass 321.420 g·mol−1
3D model (JSmol)
  • CCCCCn1cc(c2c1cccc2)C(=O)c3ccc(cc3)OC
  • InChI=1S/C21H23NO2/c1-3-4-7-14-22-15-19(18-8-5-6-9-20(18)22)21(23)16-10-12-17(24-2)13-11-16/h5-6,8-13,15H,3-4,7,14H2,1-2H3 Yes check.svgY
  • Key:OZCYJKDWRUIFFE-UHFFFAOYSA-N Yes check.svgY
 X mark.svgNYes check.svgY  (what is this?)    (verify)

RCS-4, or 1-pentyl-3-(4-methoxybenzoyl)indole, is a synthetic cannabinoid drug sold under the names SR-19, BTM-4, or Eric-4 (later shortened to E-4), but originally, OBT-199.

Contents

Pharmacology

RCS-4 is a potent cannabinoid receptor agonist, with EC50 values of 146 nM for human CB1 receptors, and 46 nM for human CB2 receptors. [2] All methoxyphenyl regioisomers, and N-butyl homologues of RCS-4 and its regioisomers also display potent agonist activities at CB1 and CB2 receptors. [2]

Legality

RCS-4 was banned in Sweden on 1 October 2010 as a hazardous good harmful to health, after being identified as an ingredient in "herbal" synthetic cannabis products. [3] [4]

It was outlawed in Denmark on 11 March 2011. [5]

In August 2011, New Zealand added not only RCS-4 but also its 1-butyl homologue, and the 2-methoxybenzoyl isomers of both these compounds, to a temporary class drug schedule (i.e. equivalent to Class C but reviewed after 12 months, and with personal possession and use of small amounts decriminalised), which was newly created under the Misuse of Drugs Amendment Act 2011 passed a week earlier. [6] [7] [8]

As of October 2015 RCS-4 is a controlled substance in China. [9]

RCS-4 and related analogues detected in synthetic cannabis blends RCS4-analogues.png
RCS-4 and related analogues detected in synthetic cannabis blends

See also

Related Research Articles

JWH-203

JWH-203 (1-pentyl-3-(2-chlorophenylacetyl)indole) is an analgesic chemical from the phenylacetylindole family that acts as a cannabinoid agonist with approximately equal affinity at both the CB1 and CB2 receptors, having a Ki of 8.0 nM at CB1 and 7.0 nM at CB2. It was originally discovered by, and named after, John W. Huffman, but has subsequently been sold without his permission as an ingredient of synthetic cannabis smoking blends. Similar to the related 2'-methoxy compound JWH-250, the 2'-bromo compound JWH-249, and the 2'-methyl compound JWH-251, JWH-203 has a phenylacetyl group in place of the naphthoyl ring used in most aminoalkylindole cannabinoid compounds, and has the strongest in vitro binding affinity for the cannabinoid receptors of any compound in the phenylacetyl group.

JWH-210 Chemical compound

JWH-210 is an analgesic chemical from the naphthoylindole family, which acts as a potent cannabinoid agonist at both the CB1 and CB2 receptors, with Ki values of 0.46 nM at CB1 and 0.69 nM at CB2. It is one of the most potent 4-substituted naphthoyl derivatives in the naphthoylindole series, having a higher binding affinity (i.e. lower Ki) at CB1 than both its 4-methyl and 4-n-propyl homologues JWH-122 (CB1 Ki 0.69 nM) and JWH-182 (CB1 Ki 0.65 nM) respectively, and than the 4-methoxy compound JWH-081 (CB1 Ki 1.2 nM). It was discovered by and named after John W. Huffman.

JWH-007 Chemical compound

JWH-007 is an analgesic chemical from the naphthoylindole family, which acts as a cannabinoid agonist at both the CB1 and CB2 receptors. It was first reported in 1994 by a group including the noted cannabinoid chemist John W. Huffman. It was the most active of the first group of N-alkyl naphoylindoles discovered by the team led by John W Huffman, several years after the family was initially described with the discovery of the N-morpholinylethyl compounds pravadoline (WIN 48,098), JWH-200 (WIN 55,225) and WIN 55,212-2 by the Sterling Winthrop group. Several other N-alkyl substituents were found to be active by Huffman's team including the n-butyl, n-hexyl, 2-heptyl, and cyclohexylethyl groups, but it was subsequently determined that the 2-methyl group on the indole ring is not required for CB1 binding, and tends to increase affinity for CB2 instead. Consequently, the 2-desmethyl derivative of JWH-007, JWH-018, has slightly higher binding affinity for CB1, with an optimum binding of 9.00 nM at CB1 and 2.94 nM at CB2, and JWH-007 displayed optimum binding of 9.50 nM at CB1 and 2.94 nM at CB2.

JWH-019

JWH-019 is an analgesic chemical from the naphthoylindole family that acts as a cannabinoid agonist at both the CB1 and CB2 receptors. It is the N-hexyl homolog of the more common synthetic cannabinoid compound JWH-018. Unlike the butyl homolog JWH-073, which is several times weaker than JWH-018, the hexyl homolog is only slightly less potent, although extending the chain one carbon longer to the heptyl homolog JWH-020 results in dramatic loss of activity. These results show that the optimum side chain length for CB1 binding in the naphthoylindole series is the five-carbon pentyl chain, shorter than in the classical cannabinoids where a seven-carbon heptyl chain produces the most potent compounds. This difference is thought to reflect a slightly different binding conformation adopted by the naphthoylindole compounds as compared to the classical cannabinoids, and may be useful in characterizing the active site of the CB1 and CB2 receptors.

A-796,260 Chemical compound

A-796,260 is a drug developed by Abbott Laboratories that acts as a potent and selective cannabinoid CB2 receptor agonist. Replacing the aromatic 3-benzoyl or 3-naphthoyl group found in most indole derived cannabinoids with the 3-tetramethylcyclopropylmethanone group, imparts significant selectivity for CB2, and A-796,260 was found to be a highly selective CB2 agonist with little affinity for CB1, having a CB2Ki of 4.6 nM vs 945 nM at CB1. It has potent analgesic and anti-inflammatory actions in animal models, being especially effective in models of neuropathic pain, but without producing cannabis-like behavioral effects.

AM-1248

AM-1248 is a drug that acts as a moderately potent agonist for both the cannabinoid receptors CB1 and CB2, but with some dispute between sources over its exact potency and selectivity. Replacing the 3-(1-naphthoyl) group found in many indole derived cannabinoid ligands, with an adamantoyl group, generally confers significant CB2 selectivity, but reasonable CB1 affinity and selectivity is retained when an N-methylpiperidin-2-ylmethyl substitution is used at the indole 1-position. The related compound 1-pentyl-3-(1-adamantoyl)indole was identified as having been sold as a cannabinoid designer drug in Hungary in 2011, along with another synthetic cannabinoid AM-679.

AM-1220 Chemical compound

AM-1220 is a drug that acts as a potent and moderately selective agonist for the cannabinoid receptor CB1, with around 19 times selectivity for CB1 over the related CB2 receptor. It was originally invented in the early 1990s by a team led by Thomas D'Ambra at Sterling Winthrop, but has subsequently been researched by many others, most notably the team led by Alexandros Makriyannis at the University of Connecticut. The (piperidin-2-yl)methyl side chain of AM-1220 contains a stereocenter, so there are two enantiomers with quite different potency, the (R)-enantiomer having a Ki of 0.27 nM at CB1 while the (S)-enantiomer has a much weaker Ki of 217 nM.

MDA-19 Chemical compound

MDA-19 (also known as BZO-HEXOXIZID) is a drug that acts as a potent and selective agonist for the cannabinoid receptor CB2, with reasonable selectivity over the psychoactive CB1 receptor, though with some variation between species. In animal studies it was effective for the treatment of neuropathic pain, but did not effect rat locomotor activity in that specific study. The pharmacology of MDA-19 in rat cannabinoid receptors have been demonstrated to function differently than human cannabinoid receptors with MDA-19 binding to human CB1 receptors 6.9x higher than rat CB1 receptors.

UR-144 Chemical compound

UR-144 (TMCP-018, KM-X1, MN-001, YX-17) is a drug invented by Abbott Laboratories, that acts as a selective full agonist of the peripheral cannabinoid receptor CB2, but with much lower affinity for the psychoactive CB1 receptor.

MAM-2201 Chemical compound

MAM-2201 is a drug that presumably acts as a potent agonist for the cannabinoid receptors. It had never previously been reported in the scientific or patent literature, and was first identified by laboratories in the Netherlands and Germany in June 2011 as an ingredient in synthetic cannabis smoking blends. Like RCS-4 and AB-001, MAM-2201 thus appears to be a novel compound invented by "research chemical" suppliers specifically for grey-market recreational use. Structurally, MAM-2201 is a hybrid of two known cannabinoid compounds JWH-122 and AM-2201, both of which had previously been used as active ingredients in synthetic cannabis blends before being banned in many countries.

APINACA Chemical compound

APINACA (AKB48, N-(1-adamantyl)-1-pentyl-1H-indazole-3-carboxamide) is a drug that acts as a reasonably potent agonist for the cannabinoid receptors, with a Ki of 304.5nM and an EC50 of 585nM at CB1. It had never previously been reported in the scientific or patent literature, and was first identified by laboratories in Japan in March 2012 as an ingredient in synthetic cannabis smoking blends, along with a related compound APICA. Structurally, it closely resembles cannabinoid compounds from a University of Connecticut patent (WO 2003/035005), but with a simple pentyl chain on the indazole 1-position, and APINACA falls within the claims of this patent despite not being disclosed as an example.

XLR-11 Chemical compound

XLR-11 (5"-fluoro-UR-144 or 5F-UR-144) is a drug that acts as a potent agonist for the cannabinoid receptors CB1 and CB2 with EC50 values of 98 nM and 83 nM, respectively. It is a 3-(tetramethylcyclopropylmethanoyl)indole derivative related to compounds such as UR-144, A-796,260 and A-834,735, but it is not specifically listed in the patent or scientific literature alongside these other similar compounds, and appears to have not previously been made by Abbott Laboratories, despite falling within the claims of patent WO 2006/069196. XLR-11 was found to produce rapid, short-lived hypothermic effects in rats at doses of 3 mg/kg and 10 mg/kg, suggesting that it is of comparable potency to APICA and STS-135.

EAM-2201 Chemical compound

EAM-2201 is a drug that presumably acts as a potent agonist for the cannabinoid receptors. It had never previously been reported in the scientific or patent literature, and was first identified by laboratories in Japan in July 2012 as an ingredient in synthetic cannabis smoking blends Like the closely related MAM-2201 which had been first reported around a year earlier, EAM-2201 thus appears to be another novel compound invented by designer drug suppliers specifically for recreational use. Structurally, EAM-2201 is a hybrid of two known cannabinoid compounds JWH-210 and AM-2201, both of which had previously been used as active ingredients in synthetic cannabis blends before being banned in many countries.

APICA (synthetic cannabinoid drug) Chemical compound

APICA is an indole based drug that acts as a potent agonist for the cannabinoid receptors.

AB-PINACA Chemical compound

AB-PINACA is a compound that was first identified as a component of synthetic cannabis products in Japan in 2012.

PB-22 Chemical compound

PB-22 is a designer drug offered by online vendors as a cannabimimetic agent, and detected being sold in synthetic cannabis products in Japan in 2013. PB-22 represents a structurally unique synthetic cannabinoid chemotype, since it contains an ester linker at the indole 3-position, rather than the precedented ketone of JWH-018 and its analogs, or the amide of APICA and its analogs.

ADBICA Group of stereoisomers

ADBICA (also known as ADB-PICA) is a designer drug identified in synthetic cannabis blends in Japan in 2013. ADBICA had not previously been reported in the scientific literature prior to its sale as a component of synthetic cannabis blends. ADBICA features a carboxamide group at the 3-indole position, like SDB-001 and STS-135. The stereochemistry of the tert-butyl side-chain in the product is unresolved, though in a large series of indazole derivatives structurally similar to ADBICA that are disclosed in Pfizer patent WO 2009/106980, activity resides exclusively in the (S) enantiomers. ADBICA is a potent agonist of the CB1 receptor and CB2 receptor with an EC50 value of 0.69 nM and 1.8 nM respectively.

ADB-PINACA Chemical compound

ADB-PINACA is a cannabinoid designer drug that is an ingredient in some synthetic cannabis products. It is a potent agonist of the CB1 receptor and CB2 receptor with EC50 values of 0.52 nM and 0.88 nM respectively. Like MDMB-FUBINACA, this compound contains an amino acid residue of tert-leucine.

CUMYL-THPINACA Chemical compound

CUMYL-THPINACA (also known as SGT-42) is an indazole-3-carboxamide based synthetic cannabinoid. CUMYL-THPINACA acts as a potent agonist for the cannabinoid receptors, with approximately 6x selectivity for CB1, having an EC50 of 0.1nM for human CB1 receptors and 0.59nM for human CB2 receptors.

FUB-PB-22 Chemical compound

FUB-PB-22 (QUFUBIC) is an indole-based synthetic cannabinoid that is a potent agonist of the CB1 receptor and has been sold online as a designer drug.

References

  1. "Ustawa z dnia 15 kwietnia 2011 r. o zmianie ustawy o przeciwdziałaniu narkomanii ( Dz.U. 2011 nr 105 poz. 614 )". Internetowy System Aktów Prawnych. Retrieved 12 June 2011.
  2. 1 2 Banister SD, Stuart J, Conroy T, Longworth M, Manohar M, Beinat C, et al. (2015). "Structure–activity relationships of synthetic cannabinoid designer drug RCS-4 and its regioisomers and C4 homologues". Forensic Toxicology. 33 (2): 355–366. doi:10.1007/s11419-015-0282-9. S2CID   33994750.
  3. Swedish Code of Statutes Regulation (2010:1086).
  4. Swedish Code of Statutes Regulation (2010:1086). (pdf) Archived 2011-07-28 at the Wayback Machine
  5. "Bilag 1 - Liste over euforiserende midler omfattet af bekendtgørelsen". Ministeriet for Sundhed og Forebyggelse. Archived from the original on 4 March 2016.
  6. "Kronic ban passed by Parliament". The New Zealand Herald . NZPA. 4 August 2011. Retrieved 4 November 2011.
  7. "Synthetic cannabis off shelves by Wednesday". The New Zealand Herald . NZPA. 9 August 2011. Retrieved 4 November 2011.
  8. New Zealand Gazette. Tuesday 9 August 2011. Issue No 122, pp 3365-3366. Departmental Notices. Health. Misuse of Drugs Act 1975. Temporary Class Drug Notice.
  9. "关于印发《非药用类麻醉药品和精神药品列管办法》的通知" (in Chinese). China Food and Drug Administration. 27 September 2015. Retrieved 1 October 2015.