In vivo and in vitro metabolism of a novel β2-adrenoceptor agonist, trantinterol: metabolites isolation and identification by LC-MS/MS and NMR

Abstract

Trantinterol is a novel β(2)-adrenoceptor agonist used for the treatment of asthma. The aim of this study is to identify the metabolites of trantinterol using liquid chromatography tandem mass spectrometry (LC-MS/MS), to isolate the main metabolites, and confirm their structures by nuclear magnetic resonance (NMR). Urine, feces, bile, and blood samples of rats were obtained and analyzed. Reference standards of six metabolites were achieved with the combination of chemical synthesis, microbial transformation, and the model systems of rats. Moreover, in order to investigate the phase I metabolism of trantinterol in humans and to study the species differences between rats and humans, incubations with liver microsomes were performed. The biotransformation by a microbial model Cunninghamella blakesleana AS 3.970 was also studied. A total of 18 metabolites were identified in vivo and in vitro together, 13 of which were newly detected. Three phase I metabolites were detected in vivo and in vitro as well as in the microbial model, including the arylhydroxylamine (M1), the tert-butyl hydroxylated trantinterol (M2) and the 1-carbonyltrantinterol (M3). Another important pathway in rats is glutathione conjugation and further catabolism and oxidation to form consecutive derivatives (M4 through M10). Other metabolites include glucuronide, glucoside, and sulfate conjugates. The results of in vitro experiments indicate no species difference exists among rats, humans, and C. blakesleana AS 3.970 on the phase I metabolism of trantinterol. Our study provided the most comprehensive picture for trantinterol in vivo and in vitro metabolism to this day, and may predict its metabolism in humans.

Simultaneous quantification of trantinterol and its metabolites in human urine by ultra performance liquid chromatography–tandem mass spectrometry

“…Trantinterol-COOH was extracted from acidified samples and then trantinterol, N-OH-trantinterol and tert-OH-trantinterol was extracted from alkalized samples. Our group once used SPE to extract trantinterol and its metabolites from rat urine [2] and it is well known that SPE offers clean extracts, which is of great benefit to the expensive UPLC column. Therefore, SPE was considered.…”

“…It has exhibited both a potent trachea relaxing activity and high ␤ 2 selectivity with low cardiac side effect [1]. The arylhydroxylamine trantinterol (N-OH-trantinterol), the tert-butyl hydroxylated trantinterol (tert-OH-trantinterol) and the 1-carbonyl trantinterol (trantinterol-COOH) are the major metabolites of trantinterol in vivo [2].…”

An LC–MS/MS method for simultaneous determination of trantinterol and its major metabolite in rat plasma and its application to a comparative pharmacokinetic study

“…1b) with concentrations higher than all the other metabolites and trantinterol itself. Therefore, SPFF COOH is the major metabolite after oral administration of trantinterol [3,4]. To further characterize the pharmacokinetic and pharmacodynamic profiles of trantinterol, the quantification method with selectivity and sensitivity for determination of trantinterol and its major circulating metabolite in plasma is indispensable in order to evaluate the efficacy and safety of these compounds after administration of trantinterol to rat.…”

Trantinterol, a Novel β2-Adrenoceptor Agonist, Noncompetitively Inhibits P-Glycoprotein Functionin Vitroandin Vivo

“…Preclinical trials have revealed that trantinterol is a potent and highly selective β 2 -adrenoceptor agonist with long duration of action and low cardiac side effects 7,8 . The metabolic pathways and pharmacokinetics of trantinterol have recently been reported 9,10 . An in vitro study showed that trantinterol did not produce clinically significant cytochrome P450 inhibition or induction 11 , but its interaction with P-gp has not been characterized.…”