Further Natural Cannabinoids

Seventy cannabinoids from C. sativa have been described up to 2005 [2j. Mostly they appear in low quantities, but some of them shall be mentioned in the following overview - especially because of their fimctions in the biosynthesis of A9-THC and their use in medicinal applications. 

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A further problem was the presumed lack of, or at least a low degree of, stereospecificity of cannabinoid action. As all receptors are asymmetric, it is conceivable that their interactions with asymmetric ligands will be limited to one enantiomer only. However, synthetic (+)-zl9-THC (2) showed canna-bimimetic activity of 5-10% compared with that of the natural (-)-d9-THC (1) [19]. This observation cast doubt over the existence of a specific cannabinoid receptor and hence of a cannabinoid mediator. This presumed low degree of stereoselectivity and the above described suggestions and data on the actions of cannabinoids on membranes, delayed research aimed at the identification of a receptor-mediator cannabinoid system. 

A report [J. Natural Products 317 (1979)] on the extensive studies at the University of Mississippi shows enormous and nearly random variations in the cannabinoid content during weeks 19 to 25 of growth and deduces that it is impossible to simply classify cannabinoid variants. However, like most studies this one did not sample the same individual plants with time but sampled several plants and pooled the results. In view of the tremendous differences between plants from the same batch of seeds, we will have to await further studies of caimabinoid variation in single plants and in clones where the entire cannabinoid content of the plant can be measured during growth, thus minimizing the spurious fluctuations due to changes in other constituents. 

One important discovery took place during the 1990s when scientists found naturally occurring cannabinoid molecules in mammals, including humans, and cannabinoid receptors in the brain and the body. Researchers identified about half a dozen of these cannabinoids in the human body, which made them want to look more closely at the hundreds of cannabinoids found in marijuana. Scientists want to learn more about why the body has these natural relatives of the cannabinoids in marijuana. Further, pharmaceutical companies want to know if the cannabinoids in marijuana can help the body s own cannabinoids for some therapeutic purposes. Recent research has found, for instance, evidence that some cannabinoids, both the body s own and those found in marijuana, can control some movement disorders, such as Parkinson s disease and Tourette s syndrome, and researchers have also found indications... 

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