Biotransformation of Penindolone, an Influenza A Virus Inhibitor.

Penindolone (PND) is a novel broad-spectrum anti-Influenza A Virus (IAV) agent blocking hemagglutinin-mediated adsorption and membrane fusion. The goal of this work was to reveal the metabolic route of PND in rats. Ultra-high-performance liquid chromatography tandem high-resolution mass spectrometry (UHPLC-HRMS) was used for metabolite identification in rat bile, feces and urine after administration of PND. A total of 25 metabolites, including 9 phase I metabolites and 16 phase II metabolites, were characterized. The metabolic pathways were proposed, and metabolites were visualized via Global Natural Product Social Molecular Networking (GNPS). It was found that 65.24-80.44% of the PND presented in the formation of glucuronide conjugate products in bile, and more than 51% of prototype was excreted through feces. In in vitro metabolism of PND by rat, mouse and human liver microsomes (LMs) system, PND was discovered to be eliminated in LMs to different extents with significant species differences. The effects of chemical inhibitors of isozymes on the metabolism of PND in vitro indicated that CYP2E1/2C9/3A4 and UGT1A1/1A6/1A9 were the metabolic enzymes responsible for PND metabolism. PND metabolism in vivo could be blocked by UGTs inhibitor (ibrutinib) to a certain extent. These findings provided a basis for further research and development of PND.

Pharmacokinetics and metabolism of penindolone in rat plasma using liquid chromatography-tandem mass spectrometry.

Penindolone (PND) is a novel influenza A virus dual inhibitor that blocks hemagglutinin-mediated adsorption and membrane fusion. A sensitive and specific ultra-performance liquid chromatography-tandem mass spectrometry method was developed and validated to determine PND in rat plasma. Plasma sample preparation was a simple deproteinization with acetonitrile followed by centrifugation. Chromatographic separation was performed on a C18 column with a gradient mobile phase of acetonitrile-water containing 0.1% formic acid. Detection was carried out by electrospray ionization in negative ion multiple reaction monitoring mode. Linear detection responses were obtained for PND ranging from 1 to 1,000 ng/ml. The intra- and inter-day precision (relative standard deviations, RSD) were within 6.5%, and accuracy (relative error, RE) was within ±11.0%. The extraction recovery data for PND and internal standard (IS) were >96.0%. PND was proved to be stable during the sample storage, preparation and analytic procedures. The validated method was successfully applied to pharmacokinetic and bioavailability studies for PND in rats. The results showed the existence of twin peaks, gender difference and nonlinear pharmacokinetics for PND. In addition, two oxidation metabolites and three glucuronidation metabolites of PND were detected by ultra-high-performance liquid chromatography-high resolution mass spectrometry.

Deciphering the Diversified Metabolic Behavior of Hydroxyalkyl Ferrocidiphenols as Anticancer Complexes.

Ferrocidiphenols possessing appropriate substituents in the aliphatic chain have very promising anticancer properties, but a systematic approach to deciphering their diversified metabolic behavior has so far been lacking. Herein, we show that a series of novel ferrocidiphenols bearing different hydroxyalkyl substituents exhibit strong anticancer activity as revealed in a range of in vitro and in vivo experiments. Moreover, they display diversified oxidative transformation profiles very distinct from those of previous complexes, shown by the use of chemical and enzymatic methods and in cellulo and in vivo metabolism studies. In view of this phenomenon, unprecedented chemo-evolutionary sequences that connect all the ferrocidiphenol-related intermediates and analogues have been established. In addition, a comprehensive density functional theory (DFT) study has been performed to decipher the metabolic diversification profiles of these complexes and demonstrate the delicate modulation of carbenium ions by the ferrocenyl moiety, via either α- or ß-positional participation.