Conolidine

Last updated
Conolidine
Conolidine structure.png
Names
Systematic IUPAC name
(4E,5S)-4-Ethylidene-1,4,5,7-tetrahydro-2,5-ethanoazocino[4,3-b]inden-6(3H)-one
Identifiers
3D model (JSmol)
ChemSpider
PubChem CID
UNII
  • InChI=1S/C17H18N2O/c1-2-11-9-19-8-7-12(11)17(20)16-14(10-19)13-5-3-4-6-15(13)18-16/h2-6,12,18H,7-10H2,1H3/b11-2-/t12-/m0/s1 X mark.svgN
    Key: DBGBUYFOJXOYNY-RENATIMJSA-N X mark.svgN
  • InChI=1/C17H18N2O/c1-2-11-9-19-8-7-12(11)17(20)16-14(10-19)13-5-3-4-6-15(13)18-16/h2-6,12,18H,7-10H2,1H3/b11-2-/t12-/m0/s1
    Key: DBGBUYFOJXOYNY-RENATIMJBD
  • CC(=O)NC(=NCCC[C@H]1C(=O)N2CCC[C@@H]2C(=O)N[C@H]3C[C@H](N(C3=O)[C@H](C(=O)N[C@H](C(=O)N1)CCCC(=O)O)CC4=CN=CN4)O)N
Properties
C17H18N2O
Molar mass 266.344 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
X mark.svgN  verify  (what is  Yes check.svgYX mark.svgN ?)
Tabernaemontana divaricata Tabernaemontana divaricata.jpg
Tabernaemontana divaricata

Conolidine is an indole alkaloid. Preliminary reports suggest that it could provide analgesic effects with few of the detrimental side-effects associated with opioids such as morphine, though at present it has only been evaluated in mouse models.

Contents

Conolidine was first isolated in 2004 from the bark of the Tabernaemontana divaricata (crepe jasmine) shrub which is used in traditional Chinese medicine. [1]

The first asymmetric total synthesis of conolidine was developed by Micalizio and coworkers in 2011. [2] This synthetic route allows access to either enantiomer (mirror image) of conolidine via an early enzymatic resolution. Notably, evaluation of the synthetic material resulted in the discovery that both enantiomers of the synthetic compound show analgesic effects. [3]

Syntheses

The Micalizio route (2011) achieved the end product in 9 steps from a commercially available acetyl-pyridine. Notable reactions include a [2,3]-Still-Wittig rearrangement and a conformationally-controlled intramolecular Mannich cyclization.

The Weinreb group (2014) used a conjugative addition of an indole precursor to an oxime-substituted nitrosoalkene to generate the tetracyclic skeleton of conolidine in 4 steps. [4]

Takayama and colleagues (2016) synthesized conolidine and apparicine through a gold(I)-catalyzed exo-dig synthesis of a racemic piperidinyl aldehyde. [5]

Ohno and Fujii (2016) accessed the tricyclic pre-Mannich intermediate through a chiral gold(I) catalyzed cascade cyclization. [6]

In 2019, a six step synthesis was developed using Gold-catalyzed cyclization reaction and Pictet-Spengler reaction having 19% overall yield. [7]

Pharmacology

In 2011, the Bohn lab noted antinociception against both chemically induced and inflammation-derived pain, and experiments indicated lack of opioid receptor inhibition, but were unable to define a particular target. A 2019 study by a cross-site Australian and U.S. group discovered through cultured neuronal networks that conolidine may inhibit the Ca v2.2 channel, a mechanism seen in molecules like conotoxin. The group was unable to rule out partial polypharmacology against other targets. [8]
It has been discovered to bind to novel opioid receptor ACKR3/CXCR7. By binding to that receptor, the endogenous opioid peptides (such as endorphins and enkephalins) cannot be trapped thus increasing availability of those peptides to their target sites. [9]

Derivatives

DS54360155, a novel compound with a unique and original bicyclic skeleton, is more a potent analgesic than conolidine in mice. [10] DS39201083 [11] and DS34942424 [12] are other similar derivatives. They all lack mu-opioid activity. The researchers who found conolidine binding site ACKR3/CKCR7 also developed a synthetic analogue of it called RTI-5152-12. It displays an even greater activity on that receptor. [9]

See also

Related Research Articles

<span class="mw-page-title-main">Salvinorin A</span> Chemical compound

Salvinorin A is the main active psychotropic molecule in Salvia divinorum. Salvinorin A is considered a dissociative hallucinogen.

<span class="mw-page-title-main">Salvinorin</span> Group of chemical compounds

Salvinorins are a group of natural chemical compounds and their structural analogs. Several salvinorins have been isolated from Salvia divinorum. They are classified as diterpenoid furanolactones. Salvinorin A is a hallucinogen with dissociative effects.

δ-opioid receptor Opioid receptor named for the mouse vas deferens, where it was first characterized

The δ-opioid receptor, also known as delta opioid receptor or simply delta receptor, abbreviated DOR or DOP, is an inhibitory 7-transmembrane G-protein coupled receptor coupled to the G protein Gi/G0 and has enkephalins as its endogenous ligands. The regions of the brain where the δ-opioid receptor is largely expressed vary from species model to species model. In humans, the δ-opioid receptor is most heavily expressed in the basal ganglia and neocortical regions of the brain.

<span class="mw-page-title-main">Ohmefentanyl</span> Chemical compound

Ohmefentanyl is an extremely potent opioid analgesic drug which selectively binds to the µ-opioid receptor.

<span class="mw-page-title-main">7-Hydroxymitragynine</span> Opioid analgesic compound

7-Hydroxymitragynine (7-OH) is a terpenoid indole alkaloid from the plant Mitragyna speciosa, commonly known as kratom. It was first described in 1994 and is a natural product derived from the mitragynine present in the kratom leaf. 7-OH binds to opioid receptors like mitragynine, but research suggests that 7-OH binds with greater potency.

<span class="mw-page-title-main">Herkinorin</span> Opioid analgesic compound

Herkinorin is an opioid analgesic that is an analogue of the natural product salvinorin A. It was discovered in 2005 during structure-activity relationship studies into neoclerodane diterpenes, the family of chemical compounds of which salvinorin A is a member.

<span class="mw-page-title-main">Tebanicline</span> Chemical compound

Tebanicline is a potent synthetic nicotinic (non-opioid) analgesic drug developed by Abbott. It was developed as a less toxic analog of the potent poison dart frog-derived compound epibatidine, which is about 200 times stronger than morphine as an analgesic, but produces extremely dangerous toxic side effects. Like epibatidine, tebanicline showed potent analgesic activity against neuropathic pain in both animal and human trials, but with far less toxicity than its parent compound. It acts as a partial agonist at neuronal nicotinic acetylcholine receptors, binding to both the α3β4 and the α4β2 subtypes.

<span class="mw-page-title-main">Epiboxidine</span> Chemical compound

Epiboxidine is a chemical compound which acts as a partial agonist at neural nicotinic acetylcholine receptors, binding to both the α3β4 and the α4β2 subtypes. It was developed as a less toxic analogue of the potent frog-derived alkaloid epibatidine, which is around 200 times stronger than morphine as an analgesic but produces extremely dangerous toxic nicotinic side effects.

<span class="mw-page-title-main">YM-348</span> Chemical compound

YM-348 is an indazole derivative drug which acts as a potent and selective 5-HT2C receptor agonist, with an EC50 of 1nM and 15x selectivity over 5-HT2A, although it only has moderate selectivity of 3x over the closely related 5-HT2B receptor. It has thermogenic and anorectic effects in animal studies, making it potentially useful for the treatment of obesity.

<span class="mw-page-title-main">AM-630</span> Chemical compound

AM-630 (6-Iodopravadoline) is a drug that acts as a potent and selective inverse agonist for the cannabinoid receptor CB2, with a Ki of 32.1 nM at CB2 and 165x selectivity over CB1, at which it acted as a weak partial agonist. It is used in the study of CB2 mediated responses and has been used to investigate the possible role of CB2 receptors in the brain. AM-630 is significant as one of the first indole derived cannabinoid ligands substituted on the 6-position of the indole ring, a position that has subsequently been found to be important in determining affinity and efficacy at both the CB1 and CB2 receptors, and has led to the development of many related derivatives.

<span class="mw-page-title-main">Org 28312</span> Chemical compound

Org 28312 is a drug developed by Organon International which acts as a potent cannabinoid receptor full agonist at both the CB1 and CB2 receptors. It was developed with the aim of finding a water-soluble cannabinoid agonist suitable for intravenous use as an analgesic, but did not proceed to human trials, with the related compound Org 28611 chosen instead due to its better penetration into the brain. The structure-activity relationships of these compounds have subsequently been investigated further leading to the development of a number of more potent analogues, derived by cyclisation around the indole or piperazine rings.

<span class="mw-page-title-main">MT-45</span> Chemical compound

MT-45 (IC-6) is an opioid analgesic drug invented in the 1970s by Dainippon Pharmaceutical Co. It is chemically a 1-substituted-4-(1,2-diphenylethyl) piperazine derivative, which is structurally unrelated to most other opioid drugs. Racemic MT-45 has around 80% the potency of morphine, with almost all opioid activity residing in the (S) enantiomer. It has been used as a lead compound from which a large family of potent opioid drugs have been developed, including full agonists, partial agonists, and antagonists at the three main opioid receptor subtypes. Fluorinated derivatives of MT-45 such as 2F-MT-45 are significantly more potent as μ-opioid receptor agonists, and one of its main metabolites 1,2-diphenylethylpiperazine also blocks NMDA receptors.

<span class="mw-page-title-main">8-Carboxamidocyclazocine</span> Opioid agonist drug

8-Carboxamidocyclazocine (8-CAC) is an opioid analgesic drug related to cyclazocine, discovered by medicinal chemist Mark P. Wentland and co-workers in Cogswell Laboratory at Rensselaer Polytechnic Institute. Similarly to cyclazocine, 8-CAC acts as an agonist at both the μ- and κ-opioid receptors, but has a much longer duration of action than cyclazocine, and does not have μ antagonist activity. Unexpectedly, it was discovered that the phenolic hydroxyl group of cyclazocine could be replaced by a carboxamido group with only slight loss of potency at opioid receptors, and this discovery has subsequently been used to develop many novel opioid derivatives where the phenolic hydroxy group has been replaced by either carboxamide or a variety of larger groups. Due to their strong κ-opioid agonist activity, these drugs are not suited for use as analgesics in humans, but have instead been researched as potential drugs for the treatment of cocaine addiction.

<span class="mw-page-title-main">Ro60-0213</span> Chemical compound

Ro60-0213 is a drug developed by Hoffmann–La Roche, which acts as a potent and selective agonist for the 5-HT2C serotonin receptor, with more than 100x selectivity over other closely related serotonin receptor subtypes, and little or no affinity at other receptors. It was developed as a potential antidepressant, but was discontinued from clinical development at an early stage due to toxicity concerns. However the high selectivity of Ro60-0213 for 5-HT2C makes it of continued interest for research into serotonin receptors.

<span class="mw-page-title-main">JWH-302</span> Chemical compound

JWH-302 (1-pentyl-3-(3-methoxyphenylacetyl)indole) is an analgesic chemical from the phenylacetylindole family, which acts as a cannabinoid agonist with moderate affinity at both the CB1 and CB2 receptors. It is a positional isomer of the more common drug JWH-250, though it is slightly less potent with a Ki of 17 nM at CB1, compared to 11 nM for JWH-250. Because of their identical molecular weight and similar fragmentation patterns, JWH-302 and JWH-250 can be very difficult to distinguish by GC-MS testing.

<span class="mw-page-title-main">Substituted tryptamine</span> Class of indoles

Substituted tryptamines, or serotonin analogues, are organic compounds which may be thought of as being derived from tryptamine itself. The molecular structures of all tryptamines contain an indole ring, joined to an amino (NH2) group via an ethyl (−CH2–CH2−) sidechain. In substituted tryptamines, the indole ring, sidechain, and/or amino group are modified by substituting another group for one of the hydrogen (H) atoms.

<span class="mw-page-title-main">IBNtxA</span> Chemical compound

IBNtxA, or 3-iodobenzoyl naltrexamine, is an atypical opioid analgesic drug derived from naltrexone. In animal studies it produces potent analgesic effects that are blocked by levallorphan and so appear to be μ-opioid mediated, but it fails to produce constipation or respiratory depression, and is neither rewarding or aversive in conditioned place preference protocols. These unusual properties are thought to result from agonist action at a splice variant or heterodimer of the μ-opioid receptor, rather than at the classical full length form targeted by conventional opioid drugs.

<span class="mw-page-title-main">Mitragynine pseudoindoxyl</span> Opioid analgesic compound

Mitragynine pseudoindoxyl is a rearrangement product of 7-hydroxymitragynine and active metabolite of mitragynine. It is an analgesic being more potent than morphine.

<span class="mw-page-title-main">HS665</span> Chemical compound

HS665 is a drug which acts as a potent and selective κ-opioid receptor agonist, and has analgesic effects in animal studies. HS665 is not an agonist for the mu receptor, leading to less potential for abuse.

References

  1. Kam, T.-S.; Pang, H. S.; Choo, Y. M.; Komiyama, K. (Apr 2004). "Biologically Active Ibogan and Vallesamine Derivatives from Tabernaemontana divaricata". Chemistry & Biodiversity. 1 (4): 646–656. doi:10.1002/cbdv.200490056. PMID   17191876. S2CID   12805328.
  2. Tarselli, M. A.; Raehal, K. M.; Brasher, A. K.; Groer, C.; Cameron, M. D.; Bohn, L. M.; Micalizio, G. C. (2011). "Synthesis of Conolidine, a Potent Non-Opioid Analgesic for Tonic and Persistent Pain". Nature Chemistry. 3 (6): 449–453. Bibcode:2011NatCh...3..449T. doi:10.1038/nchem.1050. PMID   21602859.
  3. Ball, P. (May 2011). "Compound Offers Pain Relief Without the Complications". Nature. doi:10.1038/news.2011.313.
  4. Chauhan, P.S.; Weinreb, S.M. (2014). "Convergent Approach to the Tetracyclic Core of the Apparicine Class of Indole Alkaloids via a Key Intermolecular Nitrosoalkene Conjugate Addition". Journal of Organic Chemistry. 79 (13): 6389–6393. doi:10.1021/jo501067u. PMID   24927230.
  5. Takanashi, N.; Suzuki, K.; Kitajima, M.; Takayama, H. (2016). "Total Synthesis of Conolidine and Apparicine". Tetrahedron Letters. 57 (3): 375–378. doi:10.1016/j.tetlet.2015.12.029.
  6. Noae, S.; Yoshida, Y.; Oishi, S.; Fujii, N.; Ohno, H. (2016). "Total Synthesis of (+)-Conolidine by the Gold(I)-Catalyzed Cascade Cyclization of a Conjugated Enyne" (PDF). Journal of Organic Chemistry. 81 (13): 5690–5698. doi:10.1021/acs.joc.6b00720. hdl: 2433/241631 . PMID   27276227.
  7. Chen G, Wang C, Zou L, Zhu J, Li Y, Qi C (November 2019). "Six-Step Total Synthesis of (±)-Conolidine". Journal of Natural Products . 82 (11): 2972–2978. doi:10.1021/acs.jnatprod.9b00302. PMID   31686504. S2CID   207899726.
  8. Petrou, S.; Halgamuge, S.; Reid, C. A.; Osborne, P. B.; M. Varney; Li, M.; Pachernegg, S.; Morrisroe, E.; Berecki, G. (2019-01-15). "Discovering the pharmacodynamics of conolidine and cannabidiol using a cultured neuronal network based workflow". Scientific Reports. 9 (1): 121. Bibcode:2019NatSR...9..121M. doi:10.1038/s41598-018-37138-w. ISSN   2045-2322. PMC   6333801 . PMID   30644434.
  9. 1 2 The natural analgesic conolidine targets the newly identified opioid scavenger ACKR3/CXCR7” by Martyna Szpakowska, Ann M. Decker, Max Meyrath, Christie B. Palmer, Bruce E. Blough, Ojas A. Namjoshi & Andy Chevigné. Signal Transduction and Targeted Therapy
  10. Arita T, Asano M, Kubota K, Domon Y, Machinaga N, Shimada K (December 2019). "Discovery of a novel bicyclic compound, DS54360155, as an orally potent analgesic without mu-opioid receptor agonist activity". Bioorganic & Medicinal Chemistry Letters . 29 (23): 126748. doi:10.1016/j.bmcl.2019.126748. PMID   31676224. S2CID   207832139.
  11. Arita T, Asano M, Kubota K, Domon Y, Machinaga N, Shimada K (August 2019). "Discovery of conolidine derivative DS39201083 as a potent novel analgesic without mu opioid agonist activity". Bioorganic & Medicinal Chemistry Letters . 29 (15): 1938–1942. doi:10.1016/j.bmcl.2019.05.045. PMID   31147104. S2CID   171092814.
  12. Arita T, Asano M, Kubota K, Domon Y, Machinaga N, Shimada K (November 2020). "Discovery of DS34942424: An orally potent analgesic without mu opioid receptor agonist activity". Bioorganic & Medicinal Chemistry . 28 (21): 115714. doi:10.1016/j.bmc.2020.115714. PMID   33065431. S2CID   223556538.