A search of novel antimicrobial based on benzimidazole and 2-pyridone heterocycles

Microfluidics Biocatalysis System Applied for the Synthesis of N-Substituted Benzimidazole Derivatives by Aza-Michael Addition

Benzimidazole scaffolds became an attractive subject due to their broad spectrum of pharmacological activities. In this work, a methodology was developed for the synthesis of N-substituted benzimidazole derivatives from benzimidazoles and α, β-unsaturated compounds (acrylonitriles, acrylate esters, phenyl vinyl sulfone) catalyzed by lipase TL IM from Thermomyces lanuginosus in continuous-flow microreactors. Investigations were conducted on reaction parameters such as solvent, substrate ratio, reaction temperature, reactant donor/acceptor structures, and reaction time. The transformation is promoted by inexpensive and readily available lipase in methanol at 45 °C for 35 min. A wide range of β-amino sulfone, β-amino nitrile, and β-amino carbonyl compounds were efficiently and selectively synthesized in high yields (76–97%). All in all, a microfluidic biocatalysis system was applied to the synthesis of N-substituted benzimidazole derivatives, and could serve as a promising fast synthesis strategy for further research to develop novel and highly potent active drugs.

Pyridine Compounds with Antimicrobial and Antiviral Activities

In the context of the new life-threatening COVID-19 pandemic caused by the SARS-CoV-2 virus, finding new antiviral and antimicrobial compounds is a priority in current research. Pyridine is a privileged nucleus among heterocycles; its compounds have been noted for their therapeutic properties, such as antimicrobial, antiviral, antitumor, analgesic, anticonvulsant, anti-inflammatory, antioxidant, anti-Alzheimer’s, anti-ulcer or antidiabetic. It is known that a pyridine compound, which also contains a heterocycle, has improved therapeutic properties. The singular presence of the pyridine nucleus, or its one together with one or more heterocycles, as well as a simple hydrocarbon linker, or grafted with organic groups, gives the key molecule a certain geometry, which determines an interaction with a specific protein, and defines the antimicrobial and antiviral selectivity for the target molecule. Moreover, an important role of pyridine in medicinal chemistry is to improve water solubility due to its poor basicity. In this article, we aim to review the methods of synthesis of pyridine compounds, their antimicrobial and antiviral activities, the correlation of pharmaceutical properties with various groups present in molecules as well as the binding mode from Molecular Docking Studies.

Density functional theory calculations and molecular docking of 2-phenylbenzimidazoles with estrogen receptor for quantitative structure-activity relationship studies

Benzimidazole derivatives, especially 2-phenylbenzimidazole with various substituents on the C-5, C-2 and C-6 positions, are so important in pharmaceutical chemistry. Multiple linear regression was applied to predict the activity of 27 novel 2-phenylbenzimidazole derivatives as anticancer agents. At first, we made an effort to create a QSAR model for a selected series of novel 2-phenylbenzimidazole with density functional theory and molecular docking descriptors. Then, we tried to investigate the nature of the interactions between 2-phenylbenzimidazole derivatives and the estrogen receptor using the molecular docking method. Six descriptors of MATS4e, GATS5e, R6v, R1v+, dipole moment, and torsional free energy were selected for modelling. Due to docking results, increase in the binding energy, and decrease in the dipole moment could increase inhibitor activity.

Antimicrobial evaluation and docking study of some new substituted benzimidazole-2yl derivatives

Benzimidazoles incorporated biologically active heterocycles such as quinoline, triazine-3-thione, thiazole and thiadiazole, were synthesized utilizing 2-acetylbenzimidazole as a building block. The structures of the newly synthesized benzimidazoles were assured by their spectral data (IR, ¹H NMR, ¹³C- NMR and MS spectra). Most of the synthesized candidates were screened for their in vitro antimicrobial activity against Staphylococcus aureus, Escherichia coli, Bacillus pumilus and antifungal activity against (Saccharomyces cerevisiae). As a result, 2-(2-(1-(1H-benzo[d]imidazol-2-yl)ethylidene)hydrazineyl)-5-(furan-2-yl)-1,3,4-thiadiazole (14) had the most potent inhibitory activity against all tested bacteria with no antifungal inhibition. Furthermore, to gain insight into the mode of action of the synthesized compounds as antibacterial agents, docking studies were performed for the synthesized compounds in order to evaluate their activity as anti-bacterial agents. Virtual screening of the most promising compounds was performed against two bacterial proteins (DNA gyrase subunit B, and penicillin binding protein 1a) that are known targets for some antibiotics.

Dyeing Performance of Disperse Dyes on Polyester Fabrics Using Eco-Friendly Carrier and Their Antioxidant and Anticancer Activities

Both non eco- and eco-friendly carriers were utilized for accelerating the dyeing rate of polyethylene terephthalate fabrics (PET) dyed with disperse dyes at 100 °C. Fastness properties of the dyed fabrics showed good and excellent results. Finally, the prepared disperse dyes 1 and 2 showed potent anti-tumor cytotoxic activity in vitro using MCF-7 cells (human breast cancer cell line), HepG-2 cells (human Hepatocellular carcinoma), HCT-116 (colon carcinoma), A-549 cells (Lung carcinoma cell line), and anti-oxidant activities.

Antimicrobial Potential of Benzimidazole Derived Molecules

Structural resemblance of benzimidazole nucleus with purine nucleus in nucleotides makes benzimidazole derivatives attractive ligands to interact with biopolymers of a living system. The most prominent benzimidazole compound in nature is N-ribosyldimethylbenzimidazole, which serves as an axial ligand for cobalt in vitamin B12. This structural similarity prompted medicinal chemists across the globe to synthesize a variety of benzimidazole derivatives and to screen those for various biological activities, such as anticancer, hormone antagonist, antiviral, anti-HIV, anthelmintic, antiprotozoal, antimicrobial, antihypertensive, anti-inflammatory, analgesic, anxiolytic, antiallergic, coagulant, anticoagulant, antioxidant and antidiabetic activities. Hence, benzimidazole nucleus is considered as a privileged structure in drug discovery, and it is exploited by many research groups to develop numerous compounds that are purported to be antimicrobial. Despite a large volume of research in this area, no novel benzimidazole derived compound has emerged as clinically effective antimicrobial drug. In the present review, we have compiled various reports on benzimidazole derived antimicrobials, classified as monosubstituted, disubstituted, trisubstituted and tetrasubstituted benzimidazoles, bisbenzimidazoles, fused-benzimidazoles, and benzimidazole derivative-metal complexes. The purpose is to collate these research reports, and to generate a generalised outlay of benzimidazole derived molecules that can assist the medicinal chemists in selecting appropriate combination of substituents around the nucleus for designing potent antimicrobials.

Therapeutic evolution of benzimidazole derivatives in the last quinquennial period

Benzimidazole, a fused heterocycle bearing benzene and imidazole has gained considerable attention in the field of contemporary medicinal chemistry. The moiety is of substantial importance because of its wide array of pharmacological activities. This nitrogen containing heterocycle is a part of a number of therapeutically used agents. Moreover, a number of patents concerning this moiety in the last few years further highlight its worth. The present review covers the recent work published by scientists across the globe during last five years.