Coronaridine ibogamine

The Nagata group also developed a new approach to the construction of bridged aziridines via nitrene intermediates that led to the total synthesis of the indole alkaloids, ibogamine, velbanamine, and coronaridine (1968-1971). 

Iboga Tabernanthe iboga Shrub Ibogaine Ibogamine Tabernanthine Coronaridine... 

Other iboga alkaloids besides ibogaine (tabernanthine, R- and S-coronaridine, R- and S-ibogamine, and desethylcoronaridine) decrease morphine and cocaine intake in animals shortly after administration, and in some cases one day after administration (Click et al. 1994). R-ibogamine was the most consistent in this effect, reducing intake for several days after a single injection. 

Details of the syntheses, by Harley-Mason and his collaborators, of ( )-16-hydroxydihydrocleavamine,107a ( )-a- and ( )-j3-dihydrocleavamines, ( )-methoxycarbonyldihydrocleavamine, ( )-coronaridine, ( )-dihydrocatharan-thine, ( )-ibogamine, ( )-epi-ibogamine, and ( )-catharanthine have now been published.107"... 

A very ingenious method of producing the isoquinuclidine system has been applied to the syntheses of ( )-ibogamine (Scheme 20), (+ )-epi-ibogamine, and ( )-coronaridine. Central to the method is the reaction of a 4-amino-methylcyclohex-l-ene [c.g. (113)] with lead tetra-acetate to give a bridged... 

Glick et al. (96) demonstrated that ibogaine and several iboga alkaloids (tabernanthine, R- and 5-coronaridine, R- and 5-ibogamine, desethylcoro-naridine, and harmaline) reduced cocaine self-administration in rats in a dose-related fashion (2.5-80 mg/kg). For some alkaloids, these effects were seen the day after injection. O-Desmethylibogaine (40 mg/kg) (89) and 18-methoxycoronaridine (97) were also reported to inhibit cocaine selfadministration. 

Ibogamine-Cleavamine Group. Voacangine has been isolated from Pandaca retusa seeds and leaves and trunk bark and from Voacanga thouarsii. The seeds of Pandaca retusa also have coronaridine, the leaves and bark also... 

Catharanthine-Ibogamine-Cleavamine Group. The chemistry and pharmacology of alkaloids of Tabernanthe iboga have been reviewed." New extractions have resulted in the isolation of coronaridine (previously observed), voacangine, isovoacangine, and ibogamine from the bark of Ervatamia coronaria, coronaridine and 19-oxocoronaridine from the roots of Tabernaemontana... 

Fig. 4. Gas chromatogram of a mixture of terpenoid indole alkaloids 1 Apparicine 2 tubotaiwine 3 tabersonine 4 ibogamine 5 voaphylline 6 coronaridine 7 aspidosper-mine 8 pericyclivine 9 perivine 10 vobasine 11 voacangine 12 ibogaline 13 ajmalicine. The GC conditions are described in Table 4. (Dagnino et al. 1991)...

Within the iboga alkaloids, two antipodal series are produced. (-h )-Catharanthine (10), (-t-)-ibogamine (30), and (-I-)-coronaridine (23) belong to one, whereas ( —)-coro-naridine (31) and (- )-ibogamine (32) belong to the other (Atta-ur-Rahman and Basha, 1983). The occurrence of both (-t-) and (-) forms of both series of alkaloids [such as (+ )-quebrachamine (33) and (- )-quebrachamine (34)] suggests that the pathway is closely linked and possibly occurs at the stage of cyclization of a secodine precursor (Atta-ur-Rahman and Basha, 1983). 

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