Thiourea derivatives containing 4-arylthiazoles and d-glucose moiety: design, synthesis, antimicrobial activity evaluation, and molecular docking/dynamics simulations

Sulfonyl thioureas with a benzo[d]thiazole ring as dual acetylcholinesterase/butyrylcholinesterase and human monoamine oxidase A and B inhibitors: An in vitro and in silico study

A series of sulfonyl thioureas 6a-q containing a benzo[d]thiazole ring with an ester functional group was synthesized from corresponding substituted 2-aminobenzo[d]thiazoles 3a-q and p-toluenesulfonyl isothiocyanate. They had remarkable inhibitory activity against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), monoamine oxidase (MAO)-A, and MAO-B. Among thioureas, several compounds had notable activity in the order of 6k > 6 h > 6c (AChE), 6j > 6g > 6k (BChE), 6k > 6g > 6f (MAO-A), and 6i > 6k > 6h (MAO-B). Compound 6k was an inhibitor of interest due to its potent or good activity against all studied enzymes, with IC50 values of 0.027 ± 0.008 μM (AChE), 0.043 ± 0.004 μM (BChE), 0.353 ± 0.01 μM (MAO-A), and 0.716 ± 0.02 μM (MAO-B). This inhibitory capacity was comparable to that of the reference drugs for each enzyme. Kinetic studies of two compounds with potential activity, 6k (against AChE) and 6j (against BChE), had shown that both 6k and 6j followed competitive-type enzyme inhibition, with Ki constants of 24.49 and 12.16 nM, respectively. Induced fit docking studies for enzymes 4EY7, 7BO4, 2BXR, and 2BYB showed active interactions between sulfonyl thioureas of benzo[d]thiazoles and the residues in the active pocket with ligands 6k, 6i, and 6j, respectively. The stability of the ligand-protein complexes while each ligand entered the active site of each enzyme (4EY7, 7BO4, 2BXR, or 2BYB) was confirmed by molecular dynamics simulations.

Synthesis and biological evaluation of new naphthalimide-thiourea derivatives as potent antimicrobial agents active against multidrug-resistant Staphylococcus aureus and Mycobacterium tuberculosis

The emergence of antibiotic resistance to S. aureus and M. tuberculosis, particularly MRSA, VRSA, and drug-resistant tuberculosis, poses a serious threat to human health. Towards discovering new antibacterial agents, we designed and synthesized a series of new naphthalimide-thiourea derivatives and evaluated them against a panel of bacterial strains consisting of E. coli, S. aureus, K. pneumoniae, P. aeruginosa, A. baumannii and various mycobacterial pathogens. Compounds 4a, 4l, 4m, 4n, 4q, 9f, 9l, 13a, 13d, 13e, 17a, 17b, 17c, 17d, and 17e demonstrated potent antibacterial activity against S. aureus with MIC 0.03-8 μg mL-1. In addition, these compounds have also exhibited potent inhibition against MDR strains of S. aureus, including VRSA with MICs 0.06-4 μg mL-1. Compounds 4h, 4j, 4l, 4m, 4q, 4r, 9a, 9b, 9c, 9d, 9e, 9g, 9h, 9j, 13f and 17e also exhibited good antimycobacterial activity against M. tuberculosis with MIC 2-64 μg mL-1. The cytotoxicity assay using Vero cells revealed that all the compounds were non-toxic and exhibited a favorable selectivity index (SI >40). Time kill kinetics data indicated that compounds exhibited concentration-dependent killing. Furthermore, in silico studies were performed to decipher the possible mechanism of action. Comprehensively, these results highlight the potential of naphthalimide-thiourea derivatives as promising antibacterial agents.