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.

3-Alkenyl-2-oxindoles: Synthesis, antiproliferative and antiviral properties against SARS-CoV-2

Sets of 3-alkenyl-2-oxindoles (6,10,13) were synthesized in a facile synthetic pathway through acid dehydration (EtOH/HCl) of the corresponding 3-hydroxy-2-oxoindolines (5,9,12). Single crystal (10a,c) and powder (12a,26f) X-ray studies supported the structures. Compounds 6c and 10b are the most effective agents synthesized (about 3.4, 3.3 folds, respectively) against PaCa2 (pancreatic) cancer cell line relative to the standard reference used (Sunitinib). Additionally, compound 10b reveals antiproliferative properties against MCF7 (breast) cancer cell with IC₅₀ close to that of Sunitinib. CAM testing reveals that compounds 6 and 10 demonstrated qualitative and quantitative decreases in blood vessel count and diameter with efficacy comparable to that of Sunitinib, supporting their anti-angiogenic properties. Kinase inhibitory properties support their multi-targeted inhibitory activities against VEGFR-2 and c-kit in similar behavior to that of Sunitinib. Cell cycle analysis studies utilizing MCF7 exhibit that compound 6b arrests the cell cycle at G1/S phase while, 10b reveals accumulation of the tested cell at S phase. Compounds 6a and 10b reveal potent antiviral properties against SARS-CoV-2 with high selectivity index relative to the standards (hydroxychloroquine, chloroquine). Safe profile of the potent synthesized agents, against normal cells (VERO-E6, RPE1), support the possible development of better hits based on the attained observations.

Crystal structure, Hirshfeld and electronic transition analysis of 2-[(1H-benzimidazol-1-yl)meth-yl]benzoic acid

In the title compound, C15H12N2O2, the benzimidazole ring system is inclined to the benzene ring by 78.04 (10)°. The crystal structure features O-H⋯N and C-H⋯O hydrogen bonding and C-H⋯π and π-π inter-actions, which were investigated using Hirshfeld surface analysis.

Synthesis and Evaluation of Cytotoxic Activity of Certain Benzo[h]chromene Derivatives

BACKGROUND

Benzo[h]chromenes attracted great attention because of their widespread biological activities, including anti-proliferate activity, and the discovery of novel effective anti-cancer agents is imperative.

OBJECTIVE

The main objective was to synthesize new benzo[h]chromene derivatives and some reported derivatives, and then test all of them for their anti-cancer activities.

METHODS

The structures of the newly synthesized derivatives were confirmed by elemental and spectral analysis (IR, Mass, ¹H-NMR and ¹³C-NMR). 35 compounds were selected by the National Cancer Institute (NCI) for single-dose testing against 60 cell lines and 3 active compounds were selected for 5-doses testing. Also, these 3 compounds were tested as EGFR-inhibitors; using sorafenib as standard, and as Tubulin polymerization inhibitors using colchicines as a standard drug. Moreover, molecular docking study for the most active derivative on these 2 enzymes was also carried out.

RESULTS

Compounds 1a, 1c and 2b have the highest activities among all 35 tested compounds especially compound 1c.

CONCLUSION

compound 1c has promising anti-cancer activities compared to the used standards and may need further modification and investigations.

Benzimidazole based hybrids against complex diseases: A catalogue of the SAR profile

The fused heterocyclic ring system has been recognized as a privileged structure that is used as a template in medicinal chemistry for drug discovery. Benzimidazole is one of the common scaffolds found in several natural products such as histidine, purines, and an integral part of vitamin B12. This hetero-aromatic bicyclic ring system acts as a pharmacophore in various drugs of therapeutic interest and has a broad spectrum of activity. Literature reports suggest that diversely substituted benzimidazoles possess distinct pharmacological profiles with multi-targeting potential, thereby, an indispensable anchor for the development of novel therapeutic agents against complex diseases such as cancer, malaria, inflammatory disorders, microbial diseases, hypertension, etc. Thus, lots of efforts have been diverted towards exploring the therapeutic potential of benzimidazoles. Despite great efforts made by the research community, still, some multi-factorial diseases continue to progress due to their complex pathophysiology. Under these sets of circumstances, there is a need to explore this nucleus for hybrid designing with multi-targeting potential against complex diseases. Benzimidazole-based hybrids have been reported to treat multifactorial diseases, making it a scaffold of interest for various pharmaceutical companies and research groups. In this write-up, we shed light on the recent pharmacological profiles, various designing strategies, and structure-activity relationships (SAR) of different benzimidazole-based hybrids.

Design and synthesis of some β-carboline derivatives as multi-target anticancer agents

Aim: Some anticancer β-carbolines exhibited dual inhibition of topo-I and KSP. Methodology/Results: Novel β-carbolines were synthesized and screened for their anticancer activity according to the NCI protocol. Five dose assays results indicated that compounds 9, 10, 12, 17 and 20 were potent and non selective anticancer agents; the sulfanyltriazole 12 was the most potent. Compounds 10, 12 and 20 showed dual topo-I and KSP inhibition with compound 12 being the most potent. Active compounds elicited Pre-G1 apoptosis and cell cycle arrest at G2/M phase of melanoma MDA-MB-435 cells. Docking results, in silico physicochemical and absorption, distribution, metabolism, excretion (ADME) properties were appropriate. Conclusion: Compounds 10, 12 and 20 are potent apoptosis-inducing multitarget anticancer agents that act via dual inhibition of topo-I and KSP-ATPase.

Recent advances (2015-2016) in anticancer hybrids

In spite of the development of a large number of novel anticancer drugs over the years, Cancer remains as a prominent cause of death, worldwide. Numerous drugs that are currently in clinical practice have developed multidrug resistance along with fatal side effects. Therefore, the utilization of single-target therapy is incapable of providing an effective control on the malignant process. Molecular hybridization, involving a combination of two or more pharmacophores of bioactive scaffolds to generate a single molecular architecture with improved affinity and activity, in comparison to their parent molecules, has emerged as a promising strategy in recent drug discovery research. Hybrid anticancer drugs are of great therapeutic interests since they can potentially overcome most of the pharmacokinetic drawbacks encountered with conventional anticancer drugs. Strategically, the design of anticancer drugs involved the blending or linking of an anticancer drug with another anticancer drug or a carrier molecule which can efficiently target cancer cells with improved biological potential. Major advantages of hybrid anticancer drugs involved increased specificity, better patient compliance, and lower side effects along with reduction in chemo-resistance. The successful utilization of this technique in design and synthesis of novel anticancer hybrids has been well illustrated and documented in the literature. The purpose of the present review article will be to provide an emphasis on the recent developments (2015-16) in anticancer hybrids with insights into their structure-activity relationship (SAR) and mechanism of action.