One-Pot Solvent-Involved Synthesis of 5-O-Substituted 5H-Chromeno[2,3-b]pyridines

Discovery of novel 6-(piperidin-1-ylsulfonyl)-2H-chromenes targeting α-glucosidase, α-amylase, and PPAR-γ: Design, synthesis, virtual screening, and anti-diabetic activity for type 2 diabetes mellitus

A new series of 2H-chromene-based sulfonamide derivatives 3-12 has been synthesized and characterized using different spectroscopic techniques. The synthesized 2H-chromenes were synthesized by reacting activated methylene with 5-(piperidin-1-ylsulfonyl)salicylaldehyde through one-step condensation followed by intramolecular cyclization. Virtual screening of the designed molecules on α-glucosidase enzymes (PDB: 3W37 and 3A4A) exhibited good binding affinity suggesting that these derivatives may be potential α-glucosidase inhibitors. In-vitro α-glucosidase activity was conducted firstly at 100 µg/mL, and the results demonstrated good inhibitory potency with values ranging from 90.6% to 96.3% compared to IP = 95.8% for Acarbose. Furthermore, the IC50 values were determined, and the designed derivatives exhibited inhibitory potency less than 11 µg/mL. Surprisingly, two chromene derivatives 6 and 10 showed the highest potency with IC50 values of 0.975 ± 0.04 and 0.584 ± 0.02 µg/mL, respectively, compared to Acarbose (IC50 = 0.805 ± 0.03 µg/mL). Moreover, our work was extended to evaluate the in-vitro α-amylase and PPAR-γ activity as additional targets for diabetic activity. The results exhibited moderate activity on α-amylase and potency as PPAR-γ agonist making it a multiplet antidiabetic target. The most active 2H-chromenes 6 and 10 exhibited significant activity to PPAR-γ with IC50 values of 3.453 ± 0.14 and 4.653 ± 0.04 µg/mL compared to Pioglitazone (IC50 = 4.884±0.29 µg/mL) indicating that these derivatives improve insulin sensitivity by stimulating the production of small insulin-sensitive adipocytes. In-silico ADME profile analysis indicated compliance with Lipinski's and Veber's rules with excellent oral bioavailability properties. Finally, the docking simulation was conducted to explain the expected binding mode and binding affinity.

Investigating the Antibacterial Effects of Synthetic Gamma-Lactam Heterocycles on Methicillin-Resistant Staphylococcus aureus Strains and Assessing the Safety and Effectiveness of Lead Compound MFM514

Methicillin-resistant Staphylococcus aureus (MRSA) continues to be one of the main causes of hospital-acquired infections in all regions of the world, while linezolid is one of the only commercially available oral antibiotics available against this dangerous gram-positive pathogen. In this study, the antibacterial activity from 32 analogues of synthetic gamma-lactam heterocycles against MRSA was determined. Amongst screened analogues for the minimum inhibitory concentration (MIC) assay, compound MFM514 displayed good inhibitory activity with MIC values of 7.8–15.6 µg/mL against 30 MRSA and 12 methicillin-sensitive S. aureus (MSSA) clinical isolates, while cytotoxicity evaluations displayed a mean inhibitory concentration (IC50) value of > 625 µg/mL, displaying a potential to becoming as a lead compound. In subsequent animal studies for MFM514, a single-dose oral acute toxicity test revealed an estimated mean lethal dose (LD50) value of <5000 mg/kg, while in the mice infection test, a mean effective dose (ED50) value of 29.39 mg/kg was obtained via oral administration. These results suggest that gamma-lactam carbon skeleton, particularly MFM514, is highly recommended to be evaluated further as a new safe and efficacious orally delivered antibacterial agent against MRSA.

2,4-Diamino-5-(5-hydroxy-1-phenyl-3-(trifluoromethyl)-1H-pyrazol-4-yl)-5H-chromeno[2,3-b]pyridine-3-carbonitrile

5H-Chromeno[2,3-b]pyridines are important compounds with industrial, biological, and medicinal properties. In this short note, the multicomponent reaction of salicylaldehyde, malononitrile dimer, and 2-phenyl-5-(trifluoromethyl)-2,4-dihydro-3H-pyrazol-3-one in dimethyl sulfoxide at ambient temperature was investigated to give 2,4-diamino-5-(5-hydroxy-1-phenyl-3-(trifluoromethyl)-1H-pyrazol-4-yl)-5H-chromeno[2,3-b]pyridine-3-carbonitrile with good yield. The structure of the previously unknown chromeno[2,3-b]pyridine derivative was confirmed by elemental analysis, mass, nuclear magnetic resonance, and infrared spectroscopy data. The ADME (absorption, distribution, metabolism, and excretion) properties were also assessed.