Indole hallucinogens psilocin

Using tactile startle, bufotenin, a hallucinogen that does not cross the blood-brain barrier readily, also produced biphasic dose-response effects when given intraventricularly (76). After systemic administration, however, low doses of indole hallucinogens have not been reported to increase tactile startle (73). Thus LSD (20-80 Mg/kg), DMT (0.25-1.0 mg/kg), and psilocin (2.5-5.0 mg/kg) did not increase tactile startle. A slightly higher dose of LSD (100 Mg/kg) did increase startle toward the end of the test session, perhaps because of blocking habituation (see below). 

Psilocybin and psilocin are believed to work through mechanisms similar to LSD and other indole hallucinogens. Similar to LSD, chronic psilocybin in take also down-regulates 5-HT2 receptors, which parallels the development of behavioral tolerance (Buckholtz et al. 1990). 

Also known to be hallucinogenic are the indole derivatives psilocin and psilocybin found in the so-called magic mushrooms, Psilocybe species. Ingestion of these small fungi causes visual hallucinations with rapidly changing shapes and colours. Psilocybin is the phosphate of psilocin although based on 4-hydroxytryptamine, they also act on 5-HT receptors. 

Other well-known indoles that have various natural sources are skatole (3-methylindole) (2), serotonin (3), L-tryptophan (4), tryptamine (5), the plant growth hormones 3-indoleacetic acid (6) and 4-chloro-3-indoleacetic acid (7) [19], the mushroom hallucinogen psilocin (8), and the indole-derived ancient dyes indigo (9) [20] and Tyrian Purple (10) [19] (Scheme 1). 

The hallucinogens generally fall into two chemical classes. The indole alkylamines include LSD, psilocybin, psilocin, dimethyltryptamine (DMT), and diethyltrypta-mine (DET), all of which are structurally similar to serotonin. The other chemical subclass of hallucinogens contains phenylethylamine derivatives such as mescaline, MDMA, MDA, and DOM (dimethoxymethyl amphetamine). A related stimulatory hallucinogen, PCP, is a piperidine analogue that produces unique effects. 

Psilocybin is a naturally occurring hallucinogen. It exerts neurotoxic effects similar to LSD and has a chemical structure similar to the neurotransmitter serotonin in the human brain. Psilocybin is found as an indole alkaloid (nitrogen-containing organic base) in the fungal (Protista) kingdom. Often it is accompanied by the related alkaloids, psilocin, baeocystin, and norbaeocystin. 

LSD (Fig. 10-9), as the D-isomer, psilocin, and dimethyltryptamine are all potent hallucinogens containing the indole nucleus. They may therefore be viewed as serotonin analogs. They are 5-HT antagonists. 

Psilocybin (0-phosphoryl-4-hydroxy-N,N-dimethyltryptamine) is metabolised in vivo to the non-phosphorylated compoimd psilocin (4-hy droxy-N,N-dimethyl tryptamine) both these indole derivatives are hallucinogenic, probably because they are structurally similar... 

From (4), ergot alkaloids, classified as indole alkaloids are isolated.The noted semisynthetic hallucinogen LSD was prepared from lysergic acid derived fixim these alkaloids. Ibogaine, psilocine, 5-methoxy-N,N-dimethyltryptamine and N,N-dimethyltryptamine are also hallucinogens which are classified as indole alkaloids. 

Psilocybin 4-phosphoryloxy-V,V-dimethyl-trypt-amine, m.p. 220- 8°C. P. and the related compound psilocin (4-hydroxy-N,Ai-dimethyl-tryptamine, m.p. 173-176°C), are jointly responsible for the psychotropic action of the fruiting body of the Mexican hallucinogenic fungus Teonanacatl (Psihcybe mexiama). P. was the first naturally occurring phosphorylated indole derivative to be isolated. It can be hydrolysed to psilocin. Both compounds are slightly poisonous. Administered by mouth or by intramuscular injection, they cause hallucinations similar to those caused by LSD the latter is, however, about 100 times more potent. 

Indole derivatives Psilocybine and psilocine (D21.1) Hallucinogens, constituents of mushrooms of the genus Psilocyhe and Stropharia, used in Mexico... 

Kamata Y, Nishikawa M, Katagi M, TsuchUiashi H (2005) Liquid chromatography-tandem mass spectrometric determination of hallucinogenic indoles psilocin and psilocybin in magic mushrooms samples. J Eorensic Sci 50 336-340... 

In addition to marijuana (described in the last chapter), another form of plant-based drug exhibit seen in crime labs contains mescaline. This hallucinogen is obtained from the peyote (peyotl) cactus (Lophophora williamsii). Psilocyn (psilocin is also an accepted spelling) and psilocybin (psilocybine), are obtained from the mushroom Psilocybe mexicam, and are members of the indole... 

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