Facile synthesis and antiproliferative activity of new 3-cyanopyridines

Synthesis of Bis-thiazoles Tethered 1,4-Dihydropyridine and Pyridine Linkers via Simple Oxidation and their Molecular Docking as VEGFR -TK Inhibitors

AIM

In this study, a neoteric and expedient oxidation method is applied for a variety of Hantzsch 1,4-dihydropyridine derivatives such as 1,4-dihydro- 2,6-dimethyl-3,5-diacetylpyridine, 3,5-bis-hydrazono--2,6-dimethyl-1,4-dihydropyridine, and 3,5-bis-thiazoly-2,6-dimethyl-1,4-dihydro pyridines.

METHODS

This simple oxidation is based upon the in situ generation of nitrous acid from an aqueous sodium nitrite and acetic acid mixture and could be used to downgrade costs, sustain resources, and minimize chemical wastes. Also, a molecular modeling strategy was used to study the mechanism of action for various derivatives of bis-hydrazinylidene- thiazole as the protein Vascular Endothelial Growth Factor Receptor Tyrosine Kinase (VEGFR TK) inhibitor through evaluating their binding scores and modes compared with Sorafenib as a reference standard.

RESULT

The results revealed that the interaction of hydrazinylidene and thiazole as an anticancer Tyrosine Kinase inhibitor has been improved.

CONCLUSION

Additionally, the compounds exhibiting the highest activity were assessed for their potential anticancer effects against HepG-2, MCF-7, and WI-38 cells, and the outcomes demonstrated encouraging activity against cancer.

Design, synthesis, biological and computational screening of novel pyridine-based thiadiazole derivatives as prospective anti-inflammatory agents

In this study, a novel series of pyridine-based thiadiazole derivatives (NTD1-NTD5) were synthesized as prospective anti-inflammatory agents by combining substituted carboxylic acid derivatives of 5-substituted-2-amino-1,3,4-thiadiazole with nicotinoyl isothiocyanate in the presence of acetone. The newly synthesized compounds were characterized by FTIR, 1H NMR, 13C NMR, and mass spectrometry. First, the compounds underwent rigorous in vivo testing for acute toxicity and anti-inflammatory activity and the results revealed that three compounds-NTD1, NTD2, and NTD3, displayed no acute toxicity and significant anti-inflammatory activity, surpassing the efficacy of the standard drug, diclofenac. Notably, NTD3, which featured benzoic acid substitution, emerged as the most potent anti-inflammatory agent among the screened compounds. To further validate these findings, an in silico docking study was carried out against COX-2 bound to diclofenac (PDB ID: 1pxx). The computational analysis demonstrated that NTD2, and NTD3, exhibited substantial binding affinity, with the lowest binding energies (-8.5 and -8.4, kcal/mol) compared to diclofenac (-8.4 kcal/mol). This alignment between in vivo and in silico data supported the robust anti-inflammatory potential of these derivatives. Moreover, molecular dynamics simulations were conducted, extending over 100 ns, to examine the dynamic interactions between the ligands and the target protein. The results solidified NTD3's position as a leading candidate, showing potent inhibitory activity through strong and sustained interactions, including stable hydrogen bond formations. This was further confirmed by RMSD values of 2-2.5 Å and 2-3Ǻ, reinforcing NTD3's potential as a useful anti-inflammatory agent. The drug likeness analysis of NTD3 through SwissADME indicated that most of the predicted parameters including Lipinski rule were within acceptable limits. While these findings are promising, further research is necessary to elucidate the precise relationships between the chemical structures and their activity, as well as to understand the mechanisms underlying their pharmacological effects. This study lays the foundation for the development of novel anti-inflammatory therapeutics, potentially offering improved efficacy and safety profiles.

Facile one-pot synthesis and in silico study of new heterocyclic scaffolds with 4-pyridyl moiety: Mechanistic insights and X-ray crystallographic elucidation

4-Acetylpyridine 1 and malononitrile 2 were allowed to react in a 3MCRs with dimedone 3a or cyclohexa-1,3-dione 3b under reflux to afford 4-methyl-4-(pyridin-4-yl)-5,6,7,8-tetrahydro-4H-chromene derivatives 4a,b respectively. The mechanism of the reaction has been studied and the structures elucidated by analytical, spectral as well as X-ray crystallographic data. Heterocyclic compounds find widespread application in pharmaceutical and agrochemical products. Docking analyses were performed on the synthesized compounds to assess their binding modes with various amino acids of the target protein tubulin (PDB Code - 1SA0). The results indicated promising binding scores for compounds 4a and 4b, suggesting a strong affinity for the tubulin binding site. Finally, ADMET for the synthesized compounds 4a, 4b, 5, 8a and 8b were carried out. The drug likeness and pharmacokinetic properties of the prepared compounds were also evaluated. Notably, all of the novel compounds adhered to Lipinski's rule (Ro5) without any violations.

New 2-alkoxycyanopyridine derivatives as inhibitors of EGFR, HER2, and DHFR: Synthesis, anticancer evaluation, and molecular modeling studies

New series of substituted 2-alkoxycyanopyridine derivatives were synthesized and evaluated for their in vitro and in vivo anticancer activities. Comparing the evaluated activities against cancer cell lines to the broad-spectrum anticancer doxorubicin, and the kinase inhibitor sorafenib, compounds 3a, 4b, 4c, 7a, and 8d demonstrated superior anticancer efficacy with elevated safety profiles and selectivity indices, particularly against MCF7 breast cancer. For exploration of their mechanism of action, assays for inhibition of EGFR, HER2 kinase, and DHFR were performed. The promising synthesized compounds exhibited potent dual kinase EGFR/HER2 inhibitory activity with IC50values of 0.248/0.156 μM for 4b and 0.138/0.092 μM for 4c. Additionally, with IC50 values of 0.138 and 0.193 M, respectively, 4b and 4c had the greatest DHFR inhibitory activity that was comparable to methotrexate. In the MCF7 breast cancer cell line, they caused arrest at the S phase of the cell cycle and exhibited apoptosis induction activity. With restored caspase-3 immunoexpression, the anti-breast cancer assay performed in vivo of 4b and 4c demonstrated a substantial decrease in tumor volume. Results from molecular modeling were in agreement with biological assays proving the importance of the 3-caynopyridine, two substituted phenyl rings attached to central pyridine ring, and propoxy side chain moieties for binding with the receptors. As 4c works by inhibiting both EGFR/HER2 kinase, DHFR enzymes, in addition to cellular apoptosis, it could be viewed as a model of compounds possessing a multi-targeting anticancer activity. Collectively, compounds 4b and 4c might represent prototypes for further development as anticancer molecules.

Pyridine Derivatives as Insecticides─Part 4: Synthesis, Crystal Structure, and Insecticidal Activity of Some New Thienylpyridines, Thienylthieno[2,3-b]pyridines, and Related Heterocyclic Derivatives

The reaction of ethyl 5-cyano-2-methyl-4-(thiophen-2-yl)-6-thioxo-1,6-dihydropyridine-3-carboxylate (1) with 2-chloroacetamide or its N-aryl derivatives gave ethyl 6-((2-amino-2-oxoethyl)thio)-5-cyano-2-methyl-4-(thiophen-2-yl) nicotinate (2a) or its N-aryl derivatives 2b-f, respectively. Cyclization of 2a-f into their isomers 3a-f was carried out by heating in absolute ethanol in the presence of a catalytic amount of sodium ethoxide. The o-aminoamide 3a was reacted with some aryl aldehydes in refluxing ethanol containing a few drops of conc. HCl to afford the corresponding tetrahydropyrimidinones 4a-d. The cyclocondensation reaction of 3a with some cycloalkanones such as cyclopentanone and cyclohexanone gave the corresponding spiro compounds 5a,b. The crystal structures of compounds 2a and 2d were determined by single-crystal X-ray diffraction techniques. All new compounds were evaluated for their insecticidal activity toward nymphs and adults of Aphis gossypi.

New nematogenic conical-shaped supramolecular H-bonded complexes for solar energy investigations

New conical-shaped geometrical supramolecular H-bonded liquid crystal complexes were formed through 1:2 intermolecular interactions of H-bonding between flexible core (adipic acid, A) and lateral chloro-substituted azopyridines (Bn). The chains of the terminally alkoxy substituted base (n) were changed between 8 and 16 carbons. Mesomorphic and optical examinations of the prepared complexes were measured via differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). Fourier-transform infrared spectroscopy (FT-IR) was used to confirm the Fermi bands of the H- bonding interactions. Induced nematogenic mesophases that cover the whole lengths of alkoxy-chains were detected. The non-linear geometries of the designed supramolecular complexes were also confirmed via Density functional theory (DFT) calculations. It was found that the length of terminal alkoxy chain of the base moiety highly affects the geometrical structure of the investigated complexes. Moreover, it increases the thermodynamic energy and influences the geometrical parameters. The electrical properties of each of the acid component (A), the base (B16) and their 1:2 complex (A/2B16) were evaluated using the Keithley measurement-source unit. The optical properties studies showed that the influences in the optical absorption and the reduction of the energy gap of the complex compared to its individual components made the resulted supramolecular H-bonded complex soft material suitable for solar energy investigations.

Design, Synthesis, Molecular Modeling and Antitumor Evaluation of Novel Indolyl-Pyrimidine Derivatives with EGFR Inhibitory Activity

Scaffolds hybridization is a well-known drug design strategy for antitumor agents. Herein, series of novel indolyl-pyrimidine hybrids were synthesized and evaluated in vitro and in vivo for their antitumor activity. The in vitro antiproliferative activity of all compounds was obtained against MCF-7, HepG2, and HCT-116 cancer cell lines, as well as against WI38 normal cells using the resazurin assay. Compounds 1-4 showed broad spectrum cytotoxic activity against all these cancer cell lines compared to normal cells. Compound 4g showed potent antiproliferative activity against these cell lines (IC₅₀ = 5.1, 5.02, and 6.6 μM, respectively) comparable to the standard treatment (5-FU and erlotinib). In addition, the most promising group of compounds was further evaluated for their in vivo antitumor efficacy against EAC tumor bearing mice. Notably, compound 4g showed the most potent in vivo antitumor activity. The most active compounds were evaluated for their EGFR inhibitory (range 53-79%) activity. Compound 4g was found to be the most active compound against EGFR (IC₅₀ = 0.25 µM) showing equipotency as the reference treatment (erlotinib). Molecular modeling study was performed on compound 4g revealed a proper binding of this compound inside the EGFR active site comparable to erlotinib. The data suggest that compound 4g could be used as a potential anticancer agent.

Design, Synthesis and Biological Evaluation of Cyanopyridines, Pyridopyrazolopyrimidines and Pyridopyrazolotriazines as Potential Anticancer Agents

BACKGROUND

The continuous need for new anticancer drugs is never-ending task due to cancer resistance to the existing drugs.

OBJECTIVE

This article aimed to design, synthesis, characterization, and anticancer evaluation of cyanopyridines, pyridopyrazolopyrimidines and pyridopyrazolotriazines.

METHODS

Anticancer activity of the synthesized compounds was determined using MTT assay against three cancer cell lines, namely liver cancer cell line (HepG-2), pancreatic cancer cell line (PANC-1), non-small lung cancer cell line (A-549) and normal fibroblast.

RESULTS AND DISCUSSION

A series of 3-cyanopyridines (2a,b, 4, 5, 9), pyridopyrimidine (10), pyridopyrazolopyrimidines (11a-c, 12a,b, 18), pyrazolopyridine salt (13) and pyridopyrazolotriazines (16a,b) were synthesized from 3-cyano-4,6-dimethyl-2-pyridone. The synthesized compounds were evaluated in vitro for their anticancer activity and their chemical structures were determined by elemental analysis and spectroscopic data.

CONCLUSION

Some of the synthesized compounds showed remarkable anticancer activities, especially 11a exhibited superior potency to the reference drug cisplatin against A-549 (IC50 = 9.24 μg mL-1 compared to 11.76 μg mL-1 for reference drug) and was found to be safe (IC50 = 66 μg mL-1) for normal fibroblast. Furthermore, compound 16a displayed the highest activity among the tested compounds against HepG-2 (IC50 = 6.45 μg mL-1 equipotent to cisplatin) with the highest safety profile for normal fibroblast (IC50=113.97 μg mL-1).