Detection of metabolites of furanylfentanil, the new psychoactive substance, in rat urine and serum by liquid chromatography/mass spectrometry
T14N4
I.A. Rodin, S.E. Gribkova, A.M. Grigoryev, E.V. Nikitin, V.A. Kalashnikov
The appearance of new psychoactive substance furanilfentanil [N-phenyl-N-(1-(2-phenylethyl) piperidin-4-yl) furan-2-carboxamide] in the market necessitated the determination of its chromato-mass spectrometric characteristics, as well as its metabolites, for the subsequent automated control of them in biological objects. The structure of the furanylfentanyl molecule has a significant similarity with fentanyl and its structural analogues. This article describes the detection of metabolites of furanylfentanil in urine in laboratory rats and presents data on their proposed structures. Using high-resolution liquid chromatography/mass spectrometry, a number of metabolites were discovered in urine. Among them there are the products of monohydroxylation of phenylethane and N-phenyl residues; dihydroxylation and dihydroxylation combined with methylation of the phenylethane; formation of dihydrodiol and additional hydroxylation; N-dealkylation; hydrolysis of the amide bond and additional hydroxylation. Using chromatography/mass spectrometry characteristics of furanilfentanil and its metabolites which were founded in rats urine earlier, a number of them as well as furanilfentanil itself were also discovered in postmortem blood and urine samples of humans. It has been established that the main route of biotransformation of furanylfentanyl, in both humans and rats, is a monohydroxylation of the phenylethyl fragment, formation of dihydrodiol and hydrolysis. Presented mass spectra and retention characteristics of founded metabolites can help in the detection of these (or corresponding compounds) in biological human fluids
