Rapid structural characterization of in vivo and in vitro metabolites of tinoridine using UHPLC–QTOF–MS/MS and in silico toxicological screening of its metabolites

Abstract

Tinoridine is a nonsteroidal anti-inflammatory drug and also has potent radical scavenger and antiperoxidative activity. However, metabolism of tinoridine has not been thoroughly investigated. To identify in vivo metabolites, the drug was administered to Sprague-Dawley rats (n = 5) at a dose of 20 mg kg(-1), and blood, urine and feces were collected at different time points up to 24 h. In vitro metabolism was delved by incubating the drug with rat liver microsomes and human liver microsomes. The metabolites were enriched by optimized sample preparation involving protein precipitation using acetonitrile, followed by solid-phase extraction. Data processes were carried out using multiple mass defects filters to eliminate false-positive ions. A total of 11 metabolites have been identified in urine samples including hydroxyl, dealkylated, acetylated and glucuronide metabolites; among them, some were also observed in plasma and feces samples. Only two major metabolites were formed using liver microsomal incubations. These metabolites were also observed in vivo. All the 11 metabolites, which are hitherto unknown and novel, were characterized by using ultrahigh-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry in combination with accurate mass measurements. Finally, in silico toxicological screening of all metabolites was evaluated, and two metabolites were proposed to show a certain degree of lung or liver toxicity.

Identification and characterization of vilazodone metabolites in rats and microsomes by ultrahigh‐performance liquid chromatography/quadrupole time‐of‐flight tandem mass spectrometry

“…The in vitro metabolite generation studies were performed according to reported methodology . To conduct the in vitro metabolism study, 25 μL of HLM and RLM suspensions (20 mg mL −1 ) were added to two different Eppendorf tubes containing 420 μL of 100 mM phosphate buffer (pH 7.4), respectively.…”

“…However, there are no reports on the detailed identification and characterization of in vitro and in vivo metabolites. This has prompted us to undertake comprehensive metabolite profiling of VLZ using ultrahigh‐performance liquid chromatography (UHPLC)/quadrupole time‐of‐flight (QTOF) tandem mass spectrometry (MS/MS) . The toxicity of each metabolite was predicted by an in silico tool so as to ascertain their toxic effects.…”

Thiophene-Based Compounds with Potential Anti-Inflammatory Activity

“…The first three are NSAIDs used in the treatment of pain and inflammation. Tinoridine and Tiaprofenic acid act by inhibiting COX enzymes [ 26 , 30 ], and Tinoridine presents potent antiperoxidative and radical scavenger activity [ 30 ], while Zileuton is a LOX inhibitor [ 31 ].…”

Identification and characterization of fluvastatin metabolites in rats by UHPLC/Q‐TOF/MS/MS and in silico toxicological screening of the metabolites

“…The in vitro metabolite studies were performed according to reported methodology in HLM and RLM . To conduct this study, 25 μl of HLM, RLM suspension (20 mg ml −1 ) was added to two different Eppendorf tubes containing 420 μl of 100 mM phosphate buffer (pH 7.4).…”