Molecular Modeling, Synthesis and Biological Evaluation ofN-Heteroaryl Compounds as Reverse Transcriptase Inhibitors Against HIV-1

A Critical Review on Therapeutic Potential of Benzimidazole Derivatives: A Privileged Scaffold

Benzimidazole nucleus is a predominant heterocycle displaying a wide spectrum of pharmacological activities. The privileged nature of the benzimidazole scaffold has been revealed by its presence in most small molecule drugs and in its ability to bind multiple receptors with high affinity. A literature review of the scaffold reveals several instances where structural modifications of the benzimidazole core have resulted in high-affinity lead compounds against a variety of biological targets. Hence, this structural moiety offers opportunities to discover novel, better, safe and highly potent biological agents. The goal of the present review is to compile the medicinal properties of benzimidazole derivatives with a focus on SAR (Structure-Activity Relationships).

A Comprehensive Account on Recent Progress in Pharmacological Activities of Benzimidazole Derivatives

Nowadays, nitrogenous heterocyclic molecules have attracted a great deal of interest among medicinal chemists. Among these potential heterocyclic drugs, benzimidazole scaffolds are considerably prevalent. Due to their isostructural pharmacophore of naturally occurring active biomolecules, benzimidazole derivatives have significant importance as chemotherapeutic agents in diverse clinical conditions. Researchers have synthesized plenty of benzimidazole derivatives in the last decades, amidst a large share of these compounds exerted excellent bioactivity against many ailments with outstanding bioavailability, safety, and stability profiles. In this comprehensive review, we have summarized the bioactivity of the benzimidazole derivatives reported in recent literature (2012-2021) with their available structure-activity relationship. Compounds bearing benzimidazole nucleus possess broad-spectrum pharmacological properties ranging from common antibacterial effects to the world's most virulent diseases. Several promising therapeutic candidates are undergoing human trials, and some of these are going to be approved for clinical use. However, notable challenges, such as drug resistance, costly and tedious synthetic methods, little structural information of receptors, lack of advanced software, and so on, are still viable to be overcome for further research.

New insight into the role of glutathione reductase in glutathione peroxidase-like activity determination by coupled reductase assay: Molecular Docking Study

Previously we have shown that among 15 substituted salicyloyl (2-hydroxybenzoyl) 5-seleninic acids (SSAs) 4 compounds with longer side chains or a cyclohexyl group exhibit no glutathione peroxidase (GPx)-like activity in the coupled reductase assay. Experimental inhibition of glutathione reductase (GR) by the selenenylsulfide (a main intermediate in the catalytic cycle for GPx-like activity determination) of one of the inactive compounds led us to assess the interactions between 15 selenenylsulfide compounds and the active site of GR by molecular docking. Docking results showed that S and Se atoms in selenenylsulfides of the compounds with no GPx-like activity were beyond 5 Å from S atom of Cys-58 or N atom of imidazole ring of His-467 (Root Mean Square Distances for general assessment of 3 major distances were over 4.8 Å) in the active site, so that they could not be catalyzed to be reduced by GR. Furthermore, their docking scores over 89 Kcal/mol meant that the selenenylsulfides were bound too strongly to the active site to leave it, leading eventually to inhibition of GR. We also applied the molecular docking to other GPx mimics such as ebselen, cyclic seleninate esters and di(propylaminomethylphenyl) diselenides to explain the differences in their GPx-like activity depending to the assays used. Our results suggest that the reduction of a selenenylsulfide by GR plays a positive role in GPx-like activity of GPx mimics in the coupled assay and recommended the prediction of possibility and strength of GPx-like activity by molecular docking before entering experimental research.

An Overview of Antiretroviral Agents for Treating HIV Infection in Paediatric Population

Paediatric Acquired ImmunoDeficiency Syndrome (AIDS) is a life-threatening and infectious disease in which the Human Immunodeficiency Virus (HIV) is mainly transmitted through Mother-To- Child Transmission (MTCT) during pregnancy, labour and delivery, or breastfeeding. This review provides an overview of the distinct therapeutic alternatives to abolish the systemic viral replication in paediatric HIV-1 infection. Numerous classes of antiretroviral agents have emerged as therapeutic tools for downregulation of different steps in the HIV replication process. These classes encompass Non- Nucleoside Analogue Reverse Transcriptase Inhibitors (NNRTIs), Nucleoside/Nucleotide Analogue Reverse Transcriptase Inhibitors (NRTIs/NtRTIs), INtegrase Inhibitors (INIs), Protease Inhibitors (PIs), and Entry Inhibitors (EIs). Co-administration of certain antiretroviral drugs with Pharmacokinetic Enhancers (PEs) may boost the effectiveness of the primary therapeutic agent. The combination of multiple antiretroviral drug regimens (Highly Active AntiRetroviral Therapy - HAART) is currently the standard therapeutic approach for HIV infection. So far, the use of HAART offers the best opportunity for prolonged and maximal viral suppression, and preservation of the immune system upon HIV infection. Still, the frequent administration of high doses of multiple drugs, their inefficient ability to reach the viral reservoirs in adequate doses, the development of drug resistance, and the lack of patient compliance compromise the complete HIV elimination. The development of nanotechnology-based drug delivery systems may enable targeted delivery of antiretroviral agents to inaccessible viral reservoir sites at therapeutic concentrations. In addition, the application of Computer-Aided Drug Design (CADD) approaches has provided valuable tools for the development of anti-HIV drug candidates with favourable pharmacodynamics and pharmacokinetic properties.

Recent Advances in the Design and Development of Non-nucleoside Reverse Transcriptase Inhibitor Scaffolds

Non-nucleoside reverse transcriptase inhibitors (NNRTIs) have always been an important part of the anti-HIV-1 combination therapy known as combination antiretroviral therapy (cART) since 1996. The use of NNRTIs for about 22 years has led to some mutations in the residues that compose the reverse transcriptase active site, resulting in the emergence of drug-resistant viruses. Thus, the search for new potent NNRTIs with an improved safety profile and activity against drug-resistant HIV strains is indispensable, and many hit and lead NNRTIs have been discovered in the last decade. This review provides an overview of the development in this field from 2013 to August 2018.

Synthesis of Novel Benzazole Derivatives and Evaluation of Their Antidepressant-Like Activities with Possible Underlying Mechanisms

Novel benzazole derivative compounds 4a–4h were obtained by the reaction of corresponding 2-(benzazol-2-ylthio)acetohydrazide and appropriate 4-substituted benzaldehydes. The chemical structures of the synthesized compounds were elucidated by FT-IR, ¹H-NMR, ¹³C-NMR and LCMS spectroscopic methods. Antidepressant-like effects of the compounds were evaluated by tail suspension test (TST) and modified forced swimming tests (MFST). Moreover, locomotor activities of the animals were assessed by an activity cage apparatus. In the series, compounds 4a, 4b, 4e and 4f (at 50 mg/kg) significantly decreased the immobility time of mice in both of the TST and MFST. The same compounds prolonged the swimming time of animals in MFST without any change in the climbing duration. These data indicated that compounds 4a, 4b, 4e and 4f possess significant antidepressant-like activities. Moreover, pre-treatments with p-chloro-phenylalanine methyl ester (an inhibitor of serotonin synthesis), NAN-190 (a 5-HT_1A antagonist), ketanserin (a 5-HT_2A/2C antagonist), and ondansetron (a 5-HT₃ antagonist) reversed the exhibited pharmacological effects. Results of the mechanistic studies suggested the involvement of serotonergic system and contributions of 5-HT_1A, 5-HT_2A/2C and 5-HT₃ receptors to the antidepressant-like effects of compounds 4a, 4b, 4e and 4f. Furthermore, unchanged locomotor activity of mice following the administrations of these four derivatives confirmed that the presented antidepressant-like effects are specific.