Iboga-type alkaloid

Iboga-type alkaloids are a set of monoterpene indole alkaloids comprising naturally occurring compounds found in Tabernanthe and Tabernaemontana, as well as synthetic structural analogs. Naturally occurring iboga-type alkaloids include ibogamine, ibogaine, tabernanthine, and other substituted ibogamines. Ibogaine is a hallucinogen and is referred to as an oneirogen. Many iboga-type alkaloids display biological activities such as cardiac toxicity and psychoactive effects, and some have been studied as potential treatments for drug addiction.

Naturally-occurring

Substituted ibogamines

PubChem	Name	R1	R2	R3	R4
	Ibogamine	H	H	H	H
	Ibogaine	OMe	H	H	H
	Noribogaine	OH	H	H	H
	Tabernanthine	H	OMe	H	H
	Ibogaline	OMe	OMe	H	H
	Coronaridine	H	H	CO₂Me	H
	Voacangine	OMe	H	CO₂Me	H
	Isovoacangine	H	OMe	CO₂Me	H
	Conopharyngine	OMe	OMe	CO₂Me	H
	19(S)-Hydroxyibogamine	H	H	H	OH
	Iboxygaine / Kimvuline	OMe	H	H	OH
		H	OMe	H	OH
		OMe	OMe	H	OH
	19(S)-Hydroxycoronaridine	H	H	CO₂Me	OH
	Voacristine	OMe	H	CO₂Me	OH
	Isovoacristine	H	OMe	CO₂Me	OH
	19(S)-Hydroxyconopharyngine	OMe	OMe	CO₂Me	OH

Catharanthine is an unsaturated analog of coronaridine.

Oxidation products

Similarly to other ring-constrained tryptamines such as yohimbine and mitragynine, oxidation and rearrangement products of substituted ibogamines have been reported, such as iboluteine and voaluteine.

Other alkaloids

Treatment of drug dependence

Ibogaine and related alkaloids reduce the craving for subsequent doses in individuals experiencing withdrawal symptoms associated with drug addiction. Their use has been investigated in several clinical studies involving individuals dependent on opioids, cocaine, and other substances. While positive effects—such as alleviation of withdrawal symptoms, improvement in depression, and mitigation of post-traumatic symptoms—have been confirmed, severe medical complications, including fatal cases, have also been reported due to neurotoxic and cardiotoxic side effects.

Synthetic analogues

18-MC, ME-18-MC, and 18-MAC are coronaridine analogs with similar anti-addictive effects.
More distantly related synthetic analogs include:

Varenicline, a polycyclic azepine and anti-addictive agent that similarly targets nicotinic acetylcholine receptors, but acts as a partial agonist instead.
Tabernanthalog is a structural simplification of tabernanthine and "non-hallucinogenic psychoplastogen".