Synthesis and antimicrobial activity of some 2-pyridone nucleosides containing a sulfonamide moiety

Environment benign synthesis of 5-acyl-4-hydroxypyridin-2(1H)-one derivatives as antioxidant and α-amylase inhibitors

AIM

Oxidative stress, caused by postprandial activities, is a major global health issue causing chronic diseases like diabetes mellitus, cancer, and asthma. Therefore, it was envisaged to design and synthesize a series of substituted 4-hydroxypyridine-2(1 h)-ones in order to develop new molecules that can reduce oxidative stress and modulate α-amylase activity also.

MATERIALS & METHODS

An environmentally benign, solvent and catalyst free, natural product inspired synthesis of 4-hydroxypyridin-2(1 h)-one derivatives has been developed. The synthetic analogues were evaluated in vitro α-amylase activity and antioxidant potential.

RESULTS

Among all the synthesized compounds, 4a, 4c, and 4d displayed many folds higher antioxidants activity than the standard, BHT. The in vitro α-amylase inhibition was found to be moderate with IC50 values ranging from 5.48 to 9.31 mm as compared to the standard acarbose (IC50 = 0.65 mm). The most active compound against α-amylase 4c was further investigated for its binding affinity within the active site of the enzyme and the kinetics studies revealed probable uncompetitive mode of inhibition.

CONCLUSION

Compound 4a was found to be promising antioxidant and 4c as a good α-amylase inhibitor. These compounds could pave the way for development of new α-amylase inhibitors with antioxidant capabilities thereby effectively mitigating diabetes mellitus.

Design, Synthesis, Nematicidal Evaluation, and Molecular Docking Study of Pyrano[3,2-c]pyridones against Meloidogyne incognita

Root-knot nematodes pose a serious threat to crops by affecting production and quality. Over a period of time, substantial work has been done toward the development of effective and environmentally benign nematicidal compounds. However, due to the inefficiencies of previously reported synthetics in achieving the target of safe, selective, and effective treatment, it is necessary to develop new efficacious and safer nematicidal agents considering human health and environment on top priority. This work aims to highlight the efficient and convenient l-proline catalyzed synthesis of pyrano[3,2-c]pyridone and their use as potential nematicidal agents. In vitro results of larval mortality and egg hatching inhibition revealed maximum nematicidal activity against Meloidogyne incognita from compounds 15b, 15m, and 15w with LC50 values of 28.8, 46.8, and 49.18 μg/mL at 48 h, respectively. Under similar conditions, pyrano[3,2-c]pyridones derivatives 15b (LC50 = 28.8 μg/mL) was found at par with LC50 (26.92 μg/mL) of commercial nematicide carbofuran. The in vitro results were further validated with in silico studies with the most active compound 15b nematicidal within the binding to the pocket of acetylcholine esterase (AChE). In docking, binding free energy values for compound 15b were found to be -6.90 kcal/mol. Results indicated that pyrano[3,2-c]pyridone derivatives have the potential to control M. incognita.

Synthesis and Biological Evaluation of 2-Oxo/Thioxoquinoxaline and 2-Oxo/Thioxoquinoxaline-Based Nucleoside Analogues

Several O- and S-quinoxaline glycosides have been prepared by glycosidation of 3-methyl-2-oxo(thioxo)-1,2-dihydroquinoxalines 1a,b with α-D-glucopyranosyl, α-D-galactopyranosyl, and α-D-lactosyl bromide in the presence of K2CO3 followed by deacetylation with Et3N/H2O. Furthermore, alkylation of 1a,b with 4-bromobutyl acetate, 2-acetoxyethoxymethyl bromide, and 3-chloropropanol afforded the corresponding O- and S-acycloquinoxaline nucleosides. Reaction of 1b with chloroacetic acid followed by condensation with sulfacetamide and sulfadiazine in the presence of Et3N/THF and ethyl chloroformate gave the corresponding sulfonamide derivatives 14 and 15, respectively. The structures of new compounds were confirmed by using IR, (1)H, (13)C NMR spectra and microanalysis. Some of these compounds were screened in vitro for antitumor and antifungal activities.