Metabolism of n-hexyl-homologues of delta-8-tetrahydrocannabinol and delta-9-tetrahydrocannabinol in the mouse

An emerging trend in Novel Psychoactive Substances (NPSs): designer THC

Since its discovery as one of the main components of cannabis and its affinity towards the cannabinoid receptor CB1, serving as a means to exert its psychoactivity, Δ9-tetrahydrocannabinol (Δ9-THC) has inspired medicinal chemists throughout history to create more potent derivatives. Initially, the goal was to synthesize chemical probes for investigating the molecular mechanisms behind the pharmacology of Δ9-THC and finding potential medical applications. The unintended consequence of this noble intent has been the proliferation of these compounds for recreational use. This review comprehensively covers the most exhaustive number of THC-like cannabinoids circulating on the recreational market. It provides information on the chemistry, synthesis, pharmacology, analytical assessment, and experiences related to the psychoactive effects reported by recreational users on online forums. Some of these compounds can be found in natural cannabis, albeit in trace amounts, while others are entirely artificial. Moreover, to circumvent legal issues, many manufacturers resort to semi-synthetic processes starting from legal products extracted from hemp, such as cannabidiol (CBD). Despite the aim to encompass all known THC-like molecules, new species emerge on the drug users' pipeline each month. Beyond posing a significantly high public health risk due to unpredictable and unknown side effects, scientific research consistently lags behind the rapidly evolving recreational market.

In vitro metabolism of cannabidiol in the rabbit: identification of seventeen new metabolites including thirteen dihydroxylated in the isopropenyl chain

The metabolism of cannabidiol (CBD) was studied in liver microsomes from the female New Zealand white rabbit. Metabolites were extracted with ethyl acetate, concentrated by chromatography on Sephadex LH-20 and examined as trimethylsilyl (TMS), methyl ester/TMS and (2H9)TMS derivatives by gas chromatography/mass spectrometry. Thirty-nine metabolites, mainly mono-, di- and tri-hydroxy compounds, were identified; 17 of these have not been reported before. New metabolites included 8,9-dihydroxy-8,9-dihydro-CBD (two isomers) and seven monohydroxy derivatives of each of these two compounds. The mass spectra of the TMS derivatives of metabolites not hydroxylated in the isopropenyl group were generally dominated by the ion produced by retro-Diels-Alder cleavage of the terpene ring. Other structurally informative ions included the tropylium ion and fragments diagnostic of hydroxylation at C-1", C-2", C-3", C-4" and C-7. The spectra of the TMS derivatives of metabolites hydroxylated in the isopropenyl group were generally dominated by the ion at m/z 143. This involved loss of CH2OTMS and a retro-Diels-Alder fragmentation analogous to that seen in the other metabolites, but with charge retention by the other (smaller) fragment. Other, related fragment ions also characterized these metabolites.