12-Hydroxy-LSD


12-Hydroxy-LSD is a drug of the ergoline and lysergamide families and a derivative of lysergic acid diethylamide. In terms of chemical structure, 12-hydroxy-LSD is to LSD as bufotenin is to dimethyltryptamine, with 12-hydroxy-LSD notably containing bufotenin within its conformationally constrained structure. 12-Hydroxy-LSD produces psychedelic-like effects in animals, whereas reports on its activities in humans are very limited and have been conflicting.

Pharmacology

12-Hydroxy-LSD is known to be pharmacologically active in animal studies. The drug's effects in rabbits include antiserotonergic activity and hyperthermia. In addition, like LSD, it is highly potent in terms of lethality, with a median lethal dose of 0.3mg/kg in rabbits. 12-Hydroxy-LSD also produces LSD-like electroencephalogram changes in rabbits.
According to Robert C. Pfaff and David E. Nichols and colleagues, 12-hydroxy-LSD substitutes for LSD in rodent drug discrimination tests. Hence, it appears to show psychedelic-like effects in animals. However, 12-hydroxy-LSD was described as having unremarkable properties in this assay and only having about 20 to 50% of the potency of LSD. Its reduced potency compared to LSD could be due to its increased polarity and associated pharmacokinetic differences. It was reported in the 1960s that 12-hydroxy-LSD does not produce hallucinogenic effects in humans. On the other hand however, Michael Valentine Smith claimed in his 1981 book Psychedelic Chemistry that 12-hydroxy-LSD has "about the same activity as LSD".
Presumably 12-hydroxy-LSD acts as an agonist of serotonin and dopamine receptors, as with LSD and other related lysergamides, but its pharmacology has not been studied with modern techniques.

Chemistry

Synthesis

The chemical synthesis of 12-hydroxy-LSD is described as being very difficult.

Analogues

An analogue of 12-hydroxy-LSD is 12-methoxy-LSD, which would be structurally akin to 5-MeO-DMT. As with 12-hydroxy-LSD, it has been reported that 12-methoxy-LSD is inactive as a psychedelic in humans.

History

12-Hydroxy-LSD was first described in the scientific literature by 1962. Subsequently, it was further described in the 1970s and 1980s. David E. Nichols and colleagues reported that 12-hydroxy-LSD produces psychedelic-like effects in animals in 1994. It was initially thought that 12-hydroxy-LSD might be a metabolite of LSD, but this proved not to be the case.