Poly(aniline-co-melamine)@MnFe2O4 nanocatalyst for the synthesis of 4,4′-(arylmethylene) bis (1H-pyrazole-5-ol) derivatives, and 1,4- dihydropyrano[2,3-c]pyrazoles and evaluation of their antioxidant, and anticancer activities

In this work, magnetic poly(aniline-co-melamine) nanocomposite as an efficient heterogeneous polymer-based nanocatalyst was fabricated in two steps. First, poly(aniline-co-melamine) was synthesized through the chemical oxidation by ammonium persulfate, then the magnetic nanocatalyst was successfully prepared from the in-situ coprecipitation method in the presence of poly(aniline-co-melamine). The resulting poly(aniline-co-melamine)@MnFe₂O₄ was characterized by FTIR, FESEM, XRD, VSM, EDX, TGA, and UV-vis analyses. The catalytic activity of poly(aniline-co-melamine)@MnFe₂O₄ was investigated in the synthesis of 4,4′-(arylmethylene)bis(1H-pyrazole-5-ol) derivatives, and new alkylene bridging bis 4,4′-(arylmethylene)bis(1H-pyrazole-5-ol) derivatives in excellent yields. The yield of 1,4-dihydropyrano[2,3-c]pyrazoles, 4,4′-(arylmethylene)bis(1H-pyrazol-5-ol), yields, and new alkylene bridging bis 4,4′-(arylmethylene)bis(1H-pyrazol-5-ol) derivatives were obtained 89%–96%, 90%–96%, and 92%–96%, respectively. The poly(aniline-co-melamine)@MnFe₂O₄ nanocatalyst can be recycled without pre-activation and reloaded up to five consecutive runs without a significant decrease in its efficiency. In addition, the antioxidant activity of some derivatives was evaluated by DPPH assay. Results showed that the maximum antioxidant activity of 4,4′-(arylmethylene)bis(1H-pyrazole-5-ol) derivatives and 1,4-dihydropyrano[2,3-c]pyrazoles were 75% and 90%, respectively. Furthermore, 4,4′-(arylmethylene)bis(1H-pyrazole-5-ol) derivatives and 1,4-dihydropyrano[2,3-c]pyrazoles showed good potential for destroying colon cancer cell lines. Consequently, the poly(aniline-co-melamine)@MnFe₂O₄ nanocomposite is an excellent catalyst for green chemical processes owing to its high catalytic activity, stability, and reusability.

Hercynite silica sulfuric acid: a novel inorganic sulfurous solid acid catalyst for one-pot cascade organic transformations

Herein, we delignated the synthesis of a novel inorganic sulfurous magnetic solid acid catalyst by the immobilization of an extremely high content of sulfuric acid functionalities on the amorphous silica-modified hercynite nanomagnetic core–shell via a simple method. Silica sulfuric acid (SSA) modified hercynite nanocomposite (hercynite@SSA) combines excellent recoverability and stability characteristics of hercynite (which can be regarded as a ferro spinel with Fd3m space group and cubic crystal structure) with the strong Brønsted acid properties of –SO₃H groups. This nanomagnetic solid acid was found to be an efficient and facile strong solid acid catalyst for the synthesis of bis(pyrazolyl)methanes via two different one-pot multicomponent methodologies under green conditions. The hercynite@SSA catalyst shows excellent catalytic activity and reusability in the ethanolic medium among different solid acid materials. A plausible reaction mechanism is proposed for this synthesis.

A novel inorganic sulfurous nanomagnetic solid acid composite was synthesized and its catalytic activity was evaluated in the synthesis of bis(pyrazolyl)methane derivatives. The catalyst displayed excellent activity and recoverability under green conditions.

Synthesis and Evaluation of Biological Activities of Bis(spiropyrazolone)cyclopropanes: A Potential Application against Leishmaniasis

This work focuses on the search and development of drugs that may become new alternatives to the commercial drugs currently available for treatment of leishmaniasis. We have designed and synthesized 12 derivatives of bis(spiropyrazolone)cyclopropanes. We then characterized their potential application in therapeutic use. For this, the in vitro biological activities against three eukaryotic models-S. cerevisiae, five cancer cell lines, and the parasite L. mexicana-were evaluated. In addition, cytotoxicity against non-cancerous mammalian cells has been evaluated and other properties of interest have been characterized, such as genotoxicity, antioxidant properties and, in silico predictive adsorption, distribution, metabolism, and excretion (ADME). The results that we present here represent a first screening, indicating two derivatives of bis(spiropyrazolone)cyclopropanes as good candidates for the treatment of leishmaniasis. They have good specificity against parasites with respect to mammalian cells.

Synthesis of 4,4'-(arylmethylene)bis(3-methyl-1-phenyl-1H-pyrazol-5-ols) and evaluation of their antioxidant and anticancer activities

Background

Pyrazoles have attracted particular attention due to the diverse biological activities associated with this heterocyclic system, and some have been shown to be cytotoxic to several human cell lines. Several drugs currently on the market have this heterocycle as the key structural motif, and some have been approved for the treatment of different types of cancer.

Results

4,4ʹ-(Arylmethylene)bis(1H-pyrazol-5-ols) derivatives 3a–q were synthetized by a three components reaction of 3-methyl-1-phenyl-5-pyrazolone (1) with various benzaldehydes 2 catalyzed by sodium acetate at room temperature. The structures of all synthesized compounds were characterized by physicochemical properties and spectral means (IR and NMR) and were evaluated for their radical scavenging activity by DPPH assay and tested in vitro on colorectal RKO carcinoma cells in order to determine their cytotoxic properties. All 4,4ʹ-(arylmethylene)bis(1H-pyrazol-5-ols) derivatives 3a–q were synthetized in high to excellent yield, and pure products were isolated by simple filtration. All compounds have good radical scavenging activity, and half of them are more active than ascorbic acid used as standard.

Conclusion

Several derivatives proved to be cytotoxic in the RKO cell line. In particular, compound 3i proved to be a very potent scavenger with an IC₅₀ of 6.2 ± 0.6 µM and exhibited an IC₅₀ of 9.9 ± 1.1 μM against RKO cell. Autophagy proteins were activated as a survival mechanism, whereas the predominant pathway of death was p53-mediated apoptosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13065-021-00765-y.

Chickpea leaf exudates: a green Brønsted acid type biosurfactant for bis(indole)methane and bis(pyrazolyl)methane synthesis

A clean and highly efficient protocol for green synthesis of bis(indole)methanes and bis(pyrazolyl)methanes has been successfully achieved by using a naturally sourced bio-surfactant, chickpea leaf exudates (CLE), as a Brønsted acid-type catalyst.

Natural and Synthetic Derivatives of Hydroxycinnamic Acid Modulating the Pathological Transformation of Amyloidogenic Proteins

This review presents the main properties of hydroxycinnamic acid (HCA) derivatives and their potential application as agents for the prevention and treatment of neurodegenerative diseases. It is partially focused on the successful use of these compounds as inhibitors of amyloidogenic transformation of proteins. Firstly, the prerequisites for the emergence of interest in HCA derivatives, including natural compounds, are described. A separate section is devoted to synthesis and properties of HCA derivatives. Then, the results of molecular modeling of HCA derivatives with prion protein as well as with α-synuclein fibrils are summarized, followed by detailed analysis of the experiments on the effect of natural and synthetic HCA derivatives, as well as structurally similar phenylacetic and benzoic acid derivatives, on the pathological transformation of prion protein and α-synuclein. The ability of HCA derivatives to prevent amyloid transformation of some amyloidogenic proteins, and their presence not only in food products but also as natural metabolites in human blood and tissues, makes them promising for the prevention and treatment of neurodegenerative diseases of amyloid nature.

Peroxy mediated Csp2–Csp3 dehydrogenative coupling: regioselective functionalization of coumarins and coumarin-3-carboxylic acids

Regioselective functionalization of coumarins/coumarin carboxylic acids at C-3 via activation of Csp³–H bonds of ethers under metal-free conditions is developed.

Novel nano-size and crab-like biological-based glycoluril with sulfonic acid tags as a reusable catalyst: its application to the synthesis of new mono- and bis-spiropyrans and theirin vitrobiological studies

Herein novel crab-like biological-based glycoluril with sulfonic acid tags was prepared in nano-size form and fully characterizedviaseveral techniques.

Synthesis of the first magnetic nanoparticles with a thiourea dioxide-based sulfonic acid tag: application in the one-pot synthesis of 1,1,3-tri(1H-indol-3-yl) alkanes under mild and green conditions

Synthesis of the first thiourea dioxide-based silica-coated Fe₃O₄magnetic nanoparticles as an exquisite, extraordinary and effective catalyst for the synthesis of 1,1,3-tri(1H-indol-3-yl) alkane derivatives.

Dendrimeric magnetic nanoparticle cores with Co-phthalocyanine tags and their application in the synthesis of tetrahydrobenzo[b]pyran derivatives

A novel magnetically recoverable nanocatalyst was synthesized and used for the synthesis of tetrahydrobenzo[b]pyran derivatives under mild conditions.

Experimental and theoretical studies of the nanostructured {Fe3O4@SiO2@(CH2)3Im}C(CN)3 catalyst for 2-amino-3-cyanopyridine preparation via an anomeric based oxidation

2-Amino-4,6-diphenylnicotinonitriles were prepared by using Fe₃O₄@SiO₂@(CH₂)₃Im}C(CN)₃ as a catalyst. Experimental and theoretical studies confirmed that the final step of the synthetic pathway is proceeded via an anomeric based oxidation mechanism.

Application of biological-based nano and nano magnetic catalysts in the preparation of arylbispyranylmethanes

Nano 2-carbamoylhydrazine-1-sulfonic acid, carbamoylsulfamic acid and their related nano magnetic core–shell catalysts as biological-based nano catalysts with a urea moiety were used in the synthesis of arylbispyranylmethanes.