Inhibition of Enterovirus A71 by a Novel 2-Phenyl-Benzimidazole Derivative

Abstract

Enterovirus A71 (EV-A71) infection has emerged as a significant public health concern at the global level. Epidemic events of EV-A71 have been reported worldwide, and this succession of outbreaks has heightened concern that EV-A71 may become a public health threat. In recent years, widespread A71 enterovirus also occurred in European countries. EV-A71 infection causes hand-foot-mouth disease (HFMD), herpangina, and fever. However, it can sometimes induce a variety of neurological complications, including encephalitis, aseptic meningitis, pulmonary edema, and acute flaccid paralysis. We identified new benzimidazole derivatives and described theirin vitrocytotoxicity and broad-spectrum anti-enterovirus activity. Among them, derivative 2b resulted in interesting activity against EV-A71, and therefore it was selected for further investigations. Compound 2b proved to be able to protect cell monolayers from EV-A71-induced cytopathogenicity, with an EC50 of 3 µM. Moreover, Vero-76 cells resulted in being significantly protected from necrosis and apoptosis when treated with 2b at 20 and 80 µM. Compound 2b reduced viral adsorption to Vero-76 cells, and when evaluated in a time-of-addition assay, the derivative had the highest effect when added during the infection period. Moreover, derivative 2b reduced viral penetration into host cells. Besides, 2b did not affect intestinal monolayers permeability, showing no toxic effects. A detailed insight into the efficacy of compound 2b against EV-A71 showed a dose-dependent reduction in the viral titer, also at low concentrations. Mechanism of action investigations suggested that our derivative can inhibit viral endocytosis by reducing viral attachment to and penetration into host cells. Pharmacokinetic and toxicity predictions validated compound 2b as a good candidate for furtherin vivoassays.

t‐BuONa‐Mediated Redox Condensation between o‐Nitroanilines and Benzyl Alcohols towards 2‐Phenyl Benzimidazoles under Transition‐Metal‐Free Conditions

“…In the absence of t-BuONa base, no trace of the product 3 aa was detected, implying that crucial role of the strong base (entry 18). Using more or less than 1 equivalent of t-BuONa decreased the product yield (entries [19][20][21].…”

Synthesis, Antitumor and Antiviral In Vitro Activities of New Benzotriazole-Dicarboxamide Derivatives

“…Human lung cancer cells (SK-MES 1) were seeded at the density of 8 × 10 5 cells/ml in 6-well plates (Corning, United States) with a complete medium (described in cell culture section). After overnight incubations, the cells were treated with or without different concentrations of 3b for 96 h. Cells were then labeled with Annexin V and PI as previously described ( Ibba et al, 2021 ). Stained cells were then analyzed by flow cytometry, measuring the fluorescence emission at 530 and 620 nm using 488 nm excitation laser (MoFloAstrios EQ, Beckman Coulter).…”

Human Enterovirus B: Selective Inhibition by Quinoxaline Derivatives and Bioinformatic RNA-Motif Identification as New Targets

“…After a 72 or 120 h incubation at 37 °C, cell viability was verified by the MTT method, as previously described [28]. The activity of compounds against CVB3, CVB4, CVB5, and E9 was determined in infected cell monolayers by plaque-reduction assays, as previously reported [29]. Briefly, the monolayer of Vero-76 cells or LLC-MK2 (E9) was grown overnight on a 24-well plate.…”