Application of salicylic acid as an eco‐friendly and efficient catalyst for the synthesis of 2,4,6‐triaryl pyridine, 2‐amino‐3‐cyanopyridine, and polyhydroquinoline derivatives

Synthesis of salicylic acid from wintergreen oil by green chemistry overcomes its cytotoxicity in keratinocyte cells and teratogenicity in zebrafish embryos

Salicylic acid topical is used to treat variety of skin conditions. However, salicylic acid in these products is generated through industrial synthesis and has been shown to negatively impact fetal development and cause congenital abnormalities. We hypothesized that teratogenic effects reported in salicylic acid can be prevented by naturally synthesizing salicylic acid from wintergreen oil using green chemistry method. For this purpose, we investigated the effects of natural salicylic acid (NSA) synthesized from wintergreen oil using green chemistry and synthetic salicylic acid (SSA) on keratinocyte cell (HaCaT) proliferation and zebrafish embryo development. NSA structures were analyzed by 1H NMR, 13C NMR, and GC/MS methods. Percentage inhibition against HaCaT cell was determined by MTS assay. xCelligence system was used for cellular activities. Zebrafish embryos were exposed to NSA and SSA for 72 h post-fertilization. Lipid peroxidation, nitric oxide, sialic acid, glutathione-S-transferase, catalase, and superoxide dismutase were evaluated using biochemical methods. Expressions of nqO1, gfap, bdnf, vtg, egr, cyp1a, and igf2 were determined by RT-PCR as developmental indicators. MTS and RT-cell analysis showed increased cell viability by NSA, whereas SSA decreased cell viability. NSA beneficially affected zebrafish embryo development while SSA exerted deleterious effects through oxidant-antioxidant status, inflammation, and development. Results of our study showed for the first time that synthesis of salicylic acid from wintergreen oil by green chemistry overcomes its cytotoxicity in keratinocyte cells and teratogenicity in zebrafish embryos. This finding is important for drug research on safe topical applications during pregnancy, when preventing exposure to drug and chemical-derived teratogens is vital.

Synthesis, molecular modeling Insights, and anticancer assessment of novel polyfunctionalized Pyridine congeners

The present study describes synthesizing a novel series of polyfunctionalized pyridine congeners 1-18 and assessed for cytotoxic efficacies versus HCT-116, MCF-7, and HepG-2 among one non-cancerous BJ-1 human normal cell. Most compounds were precisely potent anticancer candidate drugs. The molecular impact of the most active compounds 9, 10, 11, 13, 15, and 17 was evaluated after MCF-7 treatment. The gene expression of pro- and ant-apoptosis markers P53, Bax, Caspase-3 and Bcl-2 as well as VEGFR-2 and HER2 were determined. Compounds 13 and 15 induced upregulation of pro-apoptosis of P53, Bax, Caspase-3 and downregulation of anti-apoptosis Bcl-2 gene. However, compound 15 showed higher effect compared to 13 and respective control. Moreover, a slight reduction in HER2 gene expression was detected due to compound 15 treatment, while VEGFR-2 gene was upregulated. In agreement, the immunoblotting analysis showed higher accumulation of P53, Bax, Caspase-3 proteins and of decrease the Bcl-2 protein levels. Furthermore, docking studies united with molecular dynamic simulation exposed compounds 13 and 15 fitting in the middle of the active site at the interface linking the ATP binding site and the allosteric hydrophobic binding pocket. Finally, we performed Petra/Osiris/ Molinspiration (POM) analysis for the newly synthesized compounds. The evaluation of primary in silico parameters revealed significant differences among individual polyfunctionalized pyridine compounds, highlighting the most promising candidates. These preliminary results may help in coordinating and initiating other research projects focused on polyfunctionalized pyridine compounds, especially those with predicted bioactivity, low toxicity, optimal ADME parameters, and promising perspectives.

Hantzsch reaction using copper nitrate hydroxide-containing mesoporous silica nanoparticle with C3N4 framework as a novel powerful and reusable catalyst

Copper nitrate hydroxide (CNH)-containing mesoporous silica nanoparticle (MSN) with g-C₃N₄ framework (MSN/C₃N₄/CNH) was fabricated via a four-step hydrothermal synthesis method. Functionalized MSN-based C₃N₄ was prepared, decorated with CNH, and identified by different physicochemical techniques such as FT-IR, XRD, SEM, EDX, and STA analyses. Then, MSN/C₃N₄/CNH composite was utilized as a robust catalyst for the fast fabrication of biologically active polyhydroquinoline derivatives with high yields between 88 and 97% via Hantzsch reaction under mild reaction conditions and short reaction time (within 15 min) owing to synergistic influence of Lewis acid and base sites. Moreover, MSN/C₃N₄/CNH can be straightforwardly recovered and used up to six reaction cycles without a conspicuous decrease in efficiency.

Synthesis, properties, and application of the new nanocatalyst of double layer hydroxides in the one-pot multicomponent synthesis of 2-amino-3-cyanopyridine derivatives

A new heterogeneous nanocatalyst LDH@3-chloropyltrimethoxysilane@1,3-benzenedisulfonyl amine@Cu (LDH@TRMS@BDSA@Cu) was synthesized and confirmed by analyzes such as Fourier transform infrared spectroscopy, Field Emission Scanning Electron Microscopy, energy scattered X-ray spectroscopy (EDX), elemental mapping, X-ray diffraction analysis, heat gravity/heat derivatization (TGA) and differential scanning calorimetry. The newly synthesized nanocatalyst effectively catalyzed the reaction between different aryl aldehydes, malononitrile, different acetophenones and ammonium acetate in solvent-free conditions and they were converted into 2-amino-3-cyanopyridine derivatives with high efficiency. The reaction showed advantages such as simplicity, high stability, environmental friendliness, excellent efficiency and short time. Also, this catalyst is recyclable and was recycled 4 times without losing significant catalytic power.

One-Pot Synthesis of Benzopyrano-Pyrimidine Derivatives Catalyzed by P-Toluene Sulphonic Acid and Their Nematicidal and Molecular Docking Study

A cost-effective and environmentally benign benzopyrano-pyrimidine derivative synthesis has been established with the condensation of different salicylaldehyde derivatives, piperidine/morpholine with malononitrile, in the presence of a catalyst containing p-toluene sulphonic acid (PTSA) at 80 °C temperature. This procedure offers a new and enriched approach for synthesizing benzopyrano-pyrimidine derivatives with high yields, a straightforward experimental method, and short reaction times. The synthesized compounds were investigated for their nematocidal activity, and the result shows that among the four compounds, compounds 4 and 5 showed strong nematocidal activity against egg hatching and J2s mortality. The nematocidal efficacy of the compounds might be due to the toxicity of chemicals which are soluble in ethanol. The nematocidal effectiveness was directly related to the concentration of ethanolic dilutions of the compounds, i.e., the maximum treatment concentration, the higher the nematocidal action, or the higher the mortality and egg hatching inhibition. In the present study, with support from docking analysis, the relation between chemical reactivity and nematocidal activity of compound 4 was inferred.

A new silver coordination polymer based on 4,6-diamino-2-pyrimidinethiol: synthesis, characterization and catalytic application in asymmetric Hantzsch synthesis of polyhydroquinolines

A highly efficient and stable heterogeneous coordination polymer (CP) was successfully prepared by hydrothermal combination of silver and 4,6-diamino-2-pyrimidinethiol. The prepared coordination polymer was characterized by FT-IR, XRD, TGA, SEM, EDX, X-ray mapping and Nitrogen adsorption–desorption analysis. The prepared Ag–CP exhibit excellent catalytic activity in multicomponent Hantzsch synthesis of polyhydroquinolines under mild reaction conditions in relatively short reaction times. The heterogeneity of the catalyst was confirmed by the hot filtration test; also, the catalyst was reused for at least four times under the optimized reaction conditions without any significant loss of its catalytic activity.