An efficient and green synthesis of benzo[4,5]imidazo[1,2-a]pyrimidines using highly active and stable poly acrylic acid-supported layered double hydroxides

Recognition of GC base pairs of B-DNA by coumarin-based benzimidazopyrimidines

A novel series of Fe(III)-catalyzed crescent-shaped coumarin-appended benzo[4,5]imidazo[1,2-a]pyrimidines has been generated using a single-step multi-component approach that includes a coumarin-derived β keto ester, 2-aminobenzimidazole, and various aldehydes. The mild eco-friendly reaction conditions allowed us, for the first time, to construct a library of highly substituted benzo[4,5]imidazo[1,2-a]pyrimidine (CBPy) heterocycles with a wide range of substrate compatibility and excellent yields. This one-pot synthesis is green in nature and conforms to atom economy. The structure of one representative compound (4a) was established by X-ray crystallographic analysis. Our designed CBPys are bent in shape and capable of fitting into the minor groove of the B-DNA structure. Among all the CBPys, compound 4a exhibited the strongest binding interaction (Kd = 2.9 μM) with calf thymus DNA (ctDNA), which is known to form the B-DNA structure under the experimental conditions. A competitive binding study confirmed that the location of 4a was 43.77 Å away from the AT-rich region in the minor groove of B-DNA. It was also established that the crescent shape and the presence of coumarin were crucial for the binding of CBPys with B-DNA structures. Our results with DNA oligonucleotides of variable GC content suggest that compound 4a specifically recognizes and binds to the GC base pairs of the B-DNA structure. Thus, the CBPy class of molecules may open a new avenue for the development of novel therapeutic drugs through GC recognition.

Novel 3-substituted coumarins inspire a custom pharmacology prediction pipeline: an anticancer discovery adventure

Aim: This research aims to expand the established pharmacological space of tumor-associated carbonic anhydrases (TACAs) by exploring the synthetically accessible chemical space of 3-substituted coumarins, with the help of in silico pharmacology prediction.Materials & methods: 52 novel 3-substituted coumarins were sketched, prioritizing synthetic feasibility. Their pharmacological potentials were estimated using a custom machine-learning approach. 17 compounds were predicted as cytotoxic against HeLa cells by interfering with TACAs. Those compounds were synthesized and biologically tested against HeLa cells. The three most potent compounds were assayed against multiple carbonic anhydrases, and their enzyme binding mechanism(s) were studied using molecular docking.Results: Experimental results exhibited pronounced consensus with in silico pharmacology predictions.Conclusion: Novel 3-substituted coumarins are herein dispatched to the cancer therapeutics space.

Novel Benzo[4,5]imidazo[1,2-a]pyrimidine derivatives as selective Cyclooxygenase-2 Inhibitors: Design, synthesis, docking studies, and biological evaluation

The present study was aimed at the synthesis and evaluation of a new series of benzo[4,5]imidazo[1,2-a]pyrimidine having a methylsulfonyl group as COX-2 (cyclooxygenase-2) inhibitor pharmacophore. Molecular modeling studies were performed using the Autodock program, and the results demonstrated that methylsulfonyl pharmacophore was adequately placed into the COX-2 active site. The in vitro and in vivo COX-2 inhibitory effects were also evaluated. In the in vitro assay, all newly synthesized compounds showed moderate to good selectivity for the inhibition of the COX-2 enzyme. However, compound 2-(4-(methylsulfonyl) phenyl)-4-phenylbenzo[4,5]imidazo[1,2-a]pyrimidine (5a) showed the highest COX-2 inhibitory effect (IC₅₀: 0.05 μM) even more than celecoxib as the reference drug (IC₅₀: 0.06 μM). For the in vivo study, the writing reflex test was used, and the results indicated that all synthesized compounds had well dose-dependent anti-nociceptive activity. The in vivo evaluation also showed that compound 2-(4-(methylsulfonyl)phenyl)-4-(p-tolyl)benzo[4,5]imidazo[1,2-a]pyrimidine (5d) had the highest activity in the writing reflex test (ED₅₀: 5.75 mg/kg). In addition, the cytotoxicity effects of the synthesized compounds were tested on MCF-7 breast cancer cells, and all compounds showed considerable inhibitory results.

Pyrimido[1,2-a]benzimidazoles: synthesis and perspective of their pharmacological use

The review presents data on the synthesis as well as studies of biological activity of new derivatives of pyrimido[1,2-a]benzimidazoles published over the last decade. The bibliography of the review includes 136 sources.