Zhiyun Peng

Synthesis, molecular docking and kinetic properties of β-hydroxy-β-phenylpropionyl-hydroxamic acids as Helicobacter pylori urease inhibitors

Inhibition of urease results in Helicobacter pylori growth arrest in the stomach, promoting urease as promising targets for gastrointestinal ulcer therapy. Twenty hybrid derivatives of flavonoid scaffold and hydroxamic acid, β-hydroxy-β-phenylpropionylhydroxamic acids, were therefore synthesized and evaluated against H. pylori urease. Biological evaluation of these compounds showed improved urease inhibition exhibiting micromolar to mid-nanomolar IC50 values. Most importantly, 3-(3-chlorophenyl)-3-hydroxypropionyl-hydroxamic acid (6g) exhibited high potency with IC50 of 0.083±0.004 μM and Ki of 0.014±0.003 μM, indicating that 6g is an excellent candidate to develop novel antiulcer agent. A mixture of competitive and uncompetitive mechanism was putatively proposed to understand the inconsistency between the crystallographic and kinetic studies for the first time, which is supported by our molecular docking studies.

Synthesis, structure, molecular docking, and structure-activity relationship analysis of enamines: 3-aryl-4-alkylaminofuran-2(5H)-ones as potential antibacterials.

Thirty-one 3-aryl-4-alkylaminofuran-2(5H)-ones were designed, prepared and tested for their antibacterial activity. Some of them showed significant antibacterial activity against Gram-positive organisms, especially against Staphylococcus aureus ATCC 25923, but all were inactive against Gram-negative organisms. Out of these compounds, 3-(4-bromophenyl)-4-(2-(4-nitrophenyl)hydrazinyl)furan-2(5H)-one (4a11) showed the most potent antibacterial activity against S. aureus ATCC 25923 with MIC(50) of 0.42 μg/mL. The enzyme assay revealed that the possible antibacterial mechanism of the synthetic compounds might be due to their inhibitory activity against tyrosyl-tRNA synthetase. Molecular dockings of 4a11 into S. aureus tyrosyl-tRNA synthetase active site were also performed. This inhibitor snugly fitting the active site might well explain its excellent inhibitory activity. Meanwhile, this modeling disclosed that a more suitable optimization strategy might be to modify the benzene ring at 3-position of furanone with hydrophilic groups.

Synthesis, biological evaluation and molecular docking study of N-arylbenzo[d]oxazol-2-amines as potential α-glucosidase inhibitors.

A novel series of N-arylbenzo[d]oxazol-2-amines (4a-4m) were synthesized and evaluated for their α-glucosidase inhibitory activity. Compounds 4f-4i, 4k and 4m displayed potent inhibitory activity against α-glucosidase with IC50 values in the range of 32.49±0.17-120.24±0.51μM as compared to the standard drug acarbose. Among all tested compounds, compound 4g having 4-phenoxy substitution at the phenyl ring was found to be the most active inhibitor of α-glucosidase with an IC50 value of 32.49±0.17μM. Analysis of the kinetics of enzyme inhibition indicated that compound 4g is a noncompetitive inhibitor of α-glucosidase with a Ki value of 31.33μM. Binding interaction of compound 4g with α-glucosidase was explored by molecular docking simulation.

Synthesis and biological evaluation of novel 1,2,4-triazine derivatives bearing carbazole moiety as potent α-glucosidase inhibitors

A new series of 1,2,4-triazine derivatives bearing carbazole moiety 7a-7p were designed, synthesized, and evaluated for their α-glucosidase inhibitory activity. The majority of the screened compounds displayed potent α-glucosidase inhibitory activity, with IC50 values in the range of 4.27±0.07-47.75±0.25μM as compared to the standard drug acarbose. Among the series, compound 7k represented the most potent α-glucosidase inhibitory activity with IC50 values of 4.27±0.07μM. Kinetic analysis revealed that compound 7k is a non-competitive inhibitor with a Ki of 4.43μM. Furthermore, the binding interactions of compound 7k with α-glucosidase was confirmed through molecular docking. This study showed these 1,2,4-triazine derivatives bearing carbazole moiety as a new class of α-glucosidase inhibitors.

3-Aryl-4-acyloxyethoxyfuran-2(5H)-ones as inhibitors of tyrosyl-tRNA synthetase: Synthesis, molecular docking and antibacterial evaluation

Thirty-eight 3-aryl-4-acyloxyethoxyfuran-2(5H)-ones were designed, prepared and tested for antibacterial activities. Some of them showed significant antibacterial activity against Gram-positive organism, Gram-negative organism and fungus. Out of these compounds, 4-(2-(3-chlorophenylformyloxy)ethoxy)-3-(4-chlorophenyl)furan-2(5H)-one (d40) showed the widest spectrum of activity with MIC50 of 2.0μg/mL against Staphylococcus aureus, 4.3μg/mL against Escherichia coli, 1.5μg/mL against Pseudomonas aeruginosa and 1.2μg/mL against Candida albicans. Our data disclosed that MIC50 values against whole cell bacteria are positive correlation with MIC50 values against tyrosyl-tRNA synthetase. Meanwhile, molecular docking of d40 into S. aureus tyrosyl-tRNA synthetase active site was also performed, and the inhibitor tightly fitting the active site might be an important reason why it has high antimicrobial activity.

Design, synthesis and biological evaluation of novel coumarin thiazole derivatives as α-glucosidase inhibitors.

A new series of coumarin thiazole derivatives 7a-7t were synthesized, characterized by (1)H NMR, (13)C NMR and element analysis, evaluated for their α-glucosidase inhibitory activity. The majority of the screened compounds displayed potent inhibitory activities with IC50 values in the range of 6.24±0.07-81.69±0.39μM, when compared to the standard acarbose (IC50=43.26±0.19μM). Structure-activity relationship (SAR) studies suggest that the pattern of substitution in the phenyl ring is closely related to the biological activity of this class of compounds. Among all the tested molecules, compound 7e (IC50=6.24±0.07μM) was found to be the most active compound in the library of coumarin thiazole derivatives. Enzyme kinetic studies showed that compound 7e is a non-competitive inhibitor with a Ki of 6.86μM. Furthermore, the binding interactions of compound 7e with the active site of α-glucosidase were confirmed through molecular docking. This study has identified a new class of potent α-glucosidase inhibitors for further investigation.

Synthesis and biological evaluation of novel 2,4,5-triarylimidazole-1,2,3-triazole derivatives via click chemistry as α-glucosidase inhibitors.

A novel series of 2,4,5-triarylimidazole-1,2,3-triazole derivatives were synthesized via copper(I)-catalyzed azide-alkyne click chemistry, and evaluated for their α-glucosidase inhibitory activity. All tested compounds showed potent α-glucosidase inhibitory activity with IC50 ranging from 15.16±0.18 to 48.15±0.37μM, in comparison to the standard drug, acarbose (IC50=817.38±6.27μM). Among all the tested compounds, 5j was found to be the most active compound with IC50 value of 15.16±0.18μM and behaved as a noncompetitive inhibitor with a Ki of 14.78μM. In addition, molecular docking study was carried out to explore the binding interactions of these compounds with α-glucosidase enzyme.

Synthesis, in vitro evaluation and molecular docking studies of novel coumarin‐isatin derivatives as α‐glucosidase inhibitors

This study synthesized a series of novel coumarin‐isatin derivatives and evaluated them for α‐glucosidase inhibitory activity. The majority of the screened compounds exhibited excellent inhibition activities with IC50 values of 2.56 ± 0.08–268.79 ± 3.04 μm, when compared to acarbose. Among the newly derivatives, compound 5p was found to be the most active compound in the library of coumarin‐isatin derivatives. Furthermore, enzyme kinetic studies showed that compound 5p is a non‐competitive inhibitor with a Ki of 2.14 μm. Molecular docking analysis revealed the existence of hydrophobic and hydrogen interactions between compound 5p and the active site of α‐glucosidase. Our results indicate that coumarin‐isatin derivatives as a new class of α‐glucosidase inhibitors.