Novel Pyrrolidine-bearing quinoxaline inhibitors of DNA Gyrase, RNA polymerase and spike glycoprotein.

Anti-infective agents are a class of drugs used to prevent, treat, or control infections caused by microorganisms such as bacteria, viruses, fungi, and parasites. They play a crucial role in modern medicine, helping to reduce the severity of infections and, in many cases, save lives. This study aims at the design and synthesis of hybrid compounds containing quinoxaline, pyrrolidine, and an azo bridge to combat antimicrobial resistance, and evaluating their antimicrobial, antifungal, and antiviral activities against various pathogenic strains. Eight most potent bactericidal derivatives 2, 4, 5, 7, 9, 11, 12, and 13 were further assessed for their antibiofilm activity. Additionally, these compounds were tested for their inhibitory effects on DNA gyrase using a DNA supercoiling assay with IC50 ranging from 26.57 to 84.84 μM when compared to ciprofloxacin as standard drug. The antiviral activities were performed against HSV-1, H1N1 and SARS-CoV-2 viruses, which showed that compound 9 has the highest antiviral activity with IC50 = 0.32 µM, IC50 = 1.76 µM and 1.06 µM, respectively, as well as the best safety profile with CC50 = 30000 µM. Compound 9 displayed the highest SI value against HSV-1, H1N1 and SARS-CoV-2 with values of 93685, 17,034 and 28368, respectively. Compound 9 inhibited RdRp and spike glycoprotein (IC50 = 2.437 ± 0.102 and 1425.1 ± 55.3 nM; respectively). The physicochemical and pharmacokinetic properties of the most active compounds were screened to identify those with optimal drug-like characteristics. Molecular docking studies were conducted on the most effective compounds to elucidate their binding interactions and mechanisms of action.