2-hydroxylbenzoyl-pyrazolo[1,5-a]pyrimidines as inhibitors against bacterial pathogens and MCF7 human breast cancer cells

This article presents the synthesis of 2-hydroxybenzoyl-pyrazolo[1,5-a]pyrimidines through an acid-catalyzed reaction of substituted 3-formylchromones with 3-aminopyrazoles in up to 88 % yield. The structural elucidation of the compounds in solution was performed using NMR (¹H, ¹³C, and ¹⁹F) spectroscopy, high-resolution mass spectrometry (HR-MS), and UV–vis absorption analysis. Single X-ray crystallography analysis of 3c reveals that the molecules are consolidated by an intermolecular chalcogen bond of Se···N2 [3.301(2) Å]. Calculations of the pharmacokinetics and toxicity of the compounds were carried out using Data Warrior software and online toolkits such as Swiss ADME and GUSAR. The antibacterial activity and cytotoxicity of the compounds were assessed through in vitro and in silico approaches, followed by the calculation of the binding energy and interactions between the selected compounds and target proteins using the AutoDock 4 tool. The results showed that all compounds are predicted to be safe for consumption, obey LRo5 and Veber's rule, and are non-toxic. Compound 3h has the strongest bacteriostatic activity towards the Gram-positive bacterium Staphylococcus aureus with an inhibition zone of 8.3 ± 0.6 mm at 5 mg/mL. The molecular docking results showed that the interactions of 3h with gyrase A (PDB: 2XCT) and gyrase B (PDB: 3G75) are thermodynamically feasible with binding energies of ‒9.33 and ‒9.03 kcal/mol, respectively. In addition, 3i exhibited considerable toxicity against breast cancer adenocarcinoma MCF7 cells with an IC₅₀ of 42.9 ± 1.8 μM, potentially through its binding to the dihydroorotate dehydrogenase (DHODH) protein (PDB: 3U2O) with a binding energy of ‒9.77 kcal/mol.