(–)-2β-Carbomethoxy-3β-(4-bromophenyl)tropane (RTI-4229-51, bromopane) is a semi-synthetic alkaloid in the phenyltropane group of psychostimulant compounds. First publicized in the 1990s, it has not been used enough to have gained a fully established profile. RTI-51 can be expected to have properties lying somewhere in between RTI-31 and RTI-55. It has a ratio of monoamine reuptake inhibition of dopamine > serotonin > norepinephrine (1.8:10.6:37.4 nM respectively) which is an unusual balance of effects not produced by other commonly used compounds (although RTI-121 is similar, but more DAT selective).[1] It has been used in its 76Br radiolabelled form to map the distribution of dopamine transporters in the brain.[2]

RTI-51
Identifiers
  • methyl (1R,2S,3S,5S)-3-(4-bromophenyl)-8-methyl-8-azabicyclo[3.2.1]octane-2-carboxylate
CAS Number
PubChem CID
CompTox Dashboard (EPA)
Chemical and physical data
FormulaC16H20BrNO2
Molar mass338.245 g·mol−1
3D model (JSmol)
  • Brc1ccc(cc1)[C@H]2C[C@@H]3N(C)[C@H]([C@H]2C(=O)OC)CC3
  • InChI=1S/C16H20BrNO2/c1-18-12-7-8-14(18)15(16(19)20-2)13(9-12)10-3-5-11(17)6-4-10/h3-6,12-15H,7-9H2,1-2H3/t12-,13-,14+,15+/m1/s1 ☒N
  • Key:HNVGNUVAMRLMSG-KBXIAJHMSA-N ☒N
 ☒NcheckY (what is this?)  (verify)

Modern research seems to confirm the above hypothesis.[3] However, earlier work produced more scattered results.[4] Based upon what is obvious from the table, RTI-31, RTI-51, and RTI-55 are all similarly potent TRIs.[5][6]

MAT IC50 (and Ki) for simple phenyltropanes with 1R,2S,3S stereochemistry.[7]
Compound [3H]CFT [3H]DA [3H]Nisoxetine [3H]NE [3H]Paroxetine [3H]5-HT
Cocaine[8] 89.1 275 cf. 241 3300 (1990) 119 cf. 161 1050 (45) 177 cf. 112
WIN 35,065-2 23 49.8 920 (550) 37.2 1960 (178) 173
WIN 35,428 13.9 23.0 835 (503) 38.6 692 (63) 101
RTI-31 1.1 3.68 37 (22) 5.86 44.5 (4.0) 5.00
RTI-113[9] 1.98 5.25 2,926 242 2,340 391
RTI-51 1.7 ? 37.4 (23) ? 10.6 (0.96) ?
RTI-55 1.3 1.96 36 (22) 7.51 4.21 (0.38) 1.74
RTI-32 1.7 7.02 60 (36) 8.42 240 (23) 19.4

Data in above table is from rats brains (1995). More recent work has advocated using cloned human transporters.

See also

edit

References

edit
  1. ^ Singh S (March 2000). "Chemistry, design, and structure-activity relationship of cocaine antagonists". Chemical Reviews. 100 (3): 925–1024. doi:10.1021/cr9700538. PMID 11749256.
  2. ^ Loch C, Müller L, Ottaviani M, Halldin C, Farde L, Maziere B. Synthesis of 2β-carbomethoxy-3β-(4-[76Br]bromophenyl)tropane ([76Br]β-CBT), a PET tracer for in vivo imaging of the dopamine uptake sites. Journal of labelled compounds & radiopharmaceuticals. 1995; 36(4):385-392.
  3. ^ Wee S, Carroll FI, Woolverton WL (February 2006). "A reduced rate of in vivo dopamine transporter binding is associated with lower relative reinforcing efficacy of stimulants". Neuropsychopharmacology. 31 (2): 351–62. doi:10.1038/sj.npp.1300795. PMID 15957006. S2CID 7224342.
  4. ^ Stathis M, Scheffel U, Lever SZ, Boja JW, Carroll FI, Kuhar MJ (June 1995). "Rate of binding of various inhibitors at the dopamine transporter in vivo". Psychopharmacology. 119 (4): 376–84. doi:10.1007/BF02245852. PMID 7480516. S2CID 20022021.
  5. ^ Kimmel HL, Carroll FI, Kuhar MJ (December 2001). "Locomotor stimulant effects of novel phenyltropanes in the mouse". Drug and Alcohol Dependence. 65 (1): 25–36. doi:10.1016/S0376-8716(01)00144-2. PMID 11714587.
  6. ^ Kuhar MJ, Carroll FI, Bharat N, Landry DW (August 2001). "Anticocaine catalytic antibodies have no affinity for RTI compounds: implications for treatment". Synapse. 41 (2): 176–8. doi:10.1002/syn.1072. PMID 11400184. S2CID 11862673.
  7. ^ Carroll FI, Kotian P, Dehghani A, Gray JL, Kuzemko MA, Parham KA, et al. (January 1995). "Cocaine and 3 beta-(4'-substituted phenyl)tropane-2 beta-carboxylic acid ester and amide analogues. New high-affinity and selective compounds for the dopamine transporter". Journal of Medicinal Chemistry. 38 (2): 379–88. doi:10.1021/jm00002a020. PMID 7830281.
  8. ^ Kozikowski AP, Johnson KM, Deschaux O, Bandyopadhyay BC, Araldi GL, Carmona G, et al. (April 2003). "Mixed cocaine agonist/antagonist properties of (+)-methyl 4beta-(4-chlorophenyl)-1-methylpiperidine-3alpha-carboxylate, a piperidine-based analog of cocaine". The Journal of Pharmacology and Experimental Therapeutics. 305 (1): 143–50. doi:10.1124/jpet.102.046318. PMID 12649362. S2CID 29377097.
  9. ^ Damaj MI, Slemmer JE, Carroll FI, Martin BR (June 1999). "Pharmacological characterization of nicotine's interaction with cocaine and cocaine analogs". The Journal of Pharmacology and Experimental Therapeutics. 289 (3): 1229–36. PMID 10336510.