Determination of the Structures of Free and Glucuronidated Metabolites of α-Pyrrolidinovalerophenone in Human Urine by Liquid Chromatography–Mass Spectrometry with Accurate Mass Measurement

Abstract

The central nervous system stimulant, designer drug α-pyrrolidinovalerophenone (PVP), a member of a large group of cathinone derivatives, is highly popular among drug-dependent groups. α-Pyrrolidinovalerophenone is extensively metabolized and excreted in urine, accompanied by a significant number of metabolites. Using liquid chromatography–tandem mass spectrometry, we determined the structures of more than 60 suspected PVP metabolites present in human urine in both free and glucuronidated forms. Structural features of the metabolites were determined by interpreting high-resolution mass spectra and chromatographic retention in changing the acidity of the eluent. The compounds found are products of hydroxylation of propyl, pyrrole, and phenyl moieties, reduction of the carbonyl group to an alcohol one, carboxylation, the formation of keto groups, oxidative deamination, destruction of the pyrrole cycle to the primary amine, as well as combinations of these processes. Based on the results of measuring the relative heights of chromatographic peaks, an optimal set of metabolites is proposed for the subsequent routine screening of urine samples by liquid chromatography–mass spectrometry.