Structure-activity relationship of three synthesized benzimidazole-based oligosaccharides in human platelet activation

Synthesis, structural study and antitumor activity of novel alditol-based imidazophenanthrolines (aldo-IPs)

A series of 1H-imidazo [4,5-f][1,10] phenanthroline derivatives functionalized at 2-position with chiral, and conformationally flexible polyhydroxy alkyl chains derived from carbohydrates (alditol-based imidazophenanthrolines, aldo-IPs) is presented herein. These novel glycomimetics showed relevant and differential cytotoxic activity against several cultured tumor cell lines (PC3, HeLa and HT-29), dependent on the nature and stereochemistry of the polyhydroxy alkyl chain. The mannose-based aldo-IP demonstrated the higher cytotoxicity in the series, substantially better than cisplatin metallo-drug in all cell lines tested, and better than G-quadruplex ligand 360A in HeLa and HT29 cells. Cell cycle experiments and Annexin V-PI assays revealed that aldo-IPs induce apoptosis in HeLa cells. Initial study of DNA interactions by DNA FRET melting assays proved that the aldo-IPs produce only a slight thermal stabilization of DNA secondary structures, more pronounced in the case of quadruplex DNA. Viscosity titrations with CT dsDNA suggest that the compounds behave as DNA groove binders, whereas equilibrium dialysis assays showed that the compounds bind CT with Ka values in the range 104-105 M-1. The aldo-IP derivatives were obtained with synthetically useful yields through a feasible one-pot multistep process, by aerobic oxidative cyclization of 1,10-phenanthroline-5,6-diamine with a selection of unprotected aldoses using (NH4)2SO4 as promoter.

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.

Antiplatelet activity of new derivatives of benzimidazole containing sterically hindered phenolic group in their structure

Introduction: Cardiovascular diseases are currently the leading cause of global disability and mortality. According to the centers for disease control and prevention, the average life expectancy of a person would be 10 years longer but for a high prevalence of cardiovascular diseases, and if antiplatelet drugs and special therapy were used.

Materials and methods: Antiplatelet activity of the novel benzimidazole derivatives containing a sterically hindered phenolic group in their structure has been investigated in vitro, using a model of ADP-induced platelet aggregation of rabbit’s plasma. The compounds exhibiting high antiplatelet activity and acetylsalicylic acid, as a reference drug, were examined for antioxidant properties in an ascorbate-dependent model of lipid peroxidation.

Results: It was established that the compounds with high antiplatelet activity demonstrated the pronounced antioxidant action. The compound RU-1144 (1-(3,5-ditretbutyl-4-hydroxyphenyl) -1-hydroxypropyl)-phenyl-pyrimidobenzimidazole hydrochloride), in in vitro experiments, had a pronounced antiplatelet activity, surpassing the reference drug acetylsalicylic acid by 21.8 times; in the study of antioxidant activity, the leader compound was inferior to the reference drug dibunol by 1.7 times. By inhibiting intravascular platelet aggregation in vivo, this compound exceeded acetylsalicylic acid by 1.5 times and was slightly inferior to clopidogrel by 1.4 times.

Discussion: Benzimidazole derivatives with a hindered phenolic substituent in their structure exhibited antiplatelet and antioxidant properties. It was established that the compounds with high antiplatelet activity demonstrated the pronounced antioxidant action.

Conclusion: The chemical class of benzimidazole derivatives with a hindered phenolic substituent in their structure is promising for the search for new antiaggregant and antioxidant drugs.