Characterization of in vitro metabolites of JWH-018, JWH-073 and their 4-methyl derivatives, markers of the abuse of these synthetic cannabinoids.

In vitro incubation with human liver microsomes of JWH-018, JWH-073, JWH-122 and for the first time 1-butyl-3-(1-(4-methyl)naphthoyl)indole (the 4-methylnaphthoyl analogue of JWH-073) was investigated to identify the principal metabolites of alkylindole synthetic cannabinoids, thus helping the discovering of synthetic cannabinoids abusers. The results obtained showed that the most abundant metabolites were mono-hydroxylated derivatives either on the alkyl chain (ω or ω-1 position) or on the indole (presumably in position 5 or 6) and naphthalene moieties. Moreover the extraction conditions of these derivatives from biological fluids, mainly plasma and urine spiked with commercially available metabolite standards, and the incubation procedure were investigated to obtain a fast, reliable and suitable extraction protocol to detect either the parent drugs or their metabolites by means of GC/MS.