Preparation and Evaluation of Phenol Formaldehyde-Montmorillonite and Its Utilization in the Adsorption of Lead Ions from Aqueous Solution.

In this study, phenol formaldehyde-montmorillonite (PF-MMT) was prepared and used for lead ion (Pb2+) adsorption. Batch adsorption experiments were conducted to determine the optimal conditions. The calculated adsorption equilibrium (q) revealed that pseudo-second-order (PSO) and Langmuir isotherm models best fit the experimental data, suggesting chemisorption as the main mechanism. An adsorption capacity (qmax) of 243.9 mg/g was achieved. Fourier transform infrared (FTIR) analysis showed new peaks in PF-MMT-Pb, indicating metal complexation. Scanning electron microscopy (SEM) imaging displayed distinct Pb2+ clusters on the adsorbent surface. Adsorption was rapid, attaining equilibrium within 90 min. Effects of time, dose, concentration, and pH were systematically investigated to optimize the process. Lead ion removal efficiency reached 98.33% under optimum conditions after 90 min. The adsorption process was chemisorption based on the Dubinin-Kaganer-Radushkevich model with a free energy of 14,850 J/mol. The substantial adsorption capacity, rapid kinetics, and high removal efficiency highlight PF-MMT's potential for effective Pb2+ removal from aqueous solution.

Synthesis of some novel 2-(3-cyano -6-(thiophen- 2-yl)-4,4'- bipyridin-2- yloxy)acetohydrazide derivatives: assessment of their cytotoxic activity.

A new series of pyrazole, bipyridine, N-amide derivatives and Schiff bases was synthesized using compound 2-(3-cyano-6- (thiophen-2-yl)-4,4'- bipyridin-2-yloxy) acetohydrazide (3) as a starting material. The compounds structures were confirmed depending on the spectroscopic methods and elemental analysis. Also, the compounds were evaluated as anticancer agents by the compounds screened towards adenocarcinoma breast cancer cell line (MCF-7). The compounds showed a promising cytotoxic effect against human breast cancer cells. Compound 7c showed the most effective activity compared to other compounds with (IC50 = 0.6 ± 0.01 µg mL-1) in comparison with the reference drug doxorubicin (IC50 = 1.6 ± 0.02 µg mL-1). While compound 3 is closely active with doxorubicin. Also compounds 2, 4, 6, 7a, 7b and 7d showed noticeable cytotoxic effect. Early and late apoptotic cells were detected using Acridine orange/Ethidium bromide staining technique. The results of biologically screening of the tested compounds give an idea about the importance in the compounds acting against breast cancer and may lead to the discovery of a potent anticancer agent.

Synthesis, Characterization, Anti-proliferative Evaluation, and DNA Flow Cytometry Analysis of Some 2-Thiohydantoin Derivatives.

BACKGROUND AND OBJECTIVE: Due to the well-documented anti-proliferative activity of 2-thiohydantoin incorporated with pyrazole, oxadiazole, quinazoline, urea, ß-naphthyl carbamate and Schiff bases, they are noteworthy in pharmaceutical chemistry. METHODS: An efficient approach for the synthesis of a novel series of 2-thiohydantoin derivatives incorporated with pyrazole and oxadiazole has proceeded via the reaction of the acyl hydrazide with chalcones and/or triethyl orthoformate. Schiff bases were synthesized by the reaction of the acyl hydrazide with different aromatic aldehydes. Moreover, Curtius rearrangement was applied to the acyl azide to obtain the urea derivative, quinazoline derivative, and carbamate derivative. RESULTS: The synthesized compounds structures were discussed and confirmed depending on their spectral data. The anticancer activity of these heterocyclic compounds was evaluated against the breast cancer cell line (MCF-7), where they showed variable activity. Compound 5d found to have a superior anticancer activity, where it has (IC50 = 2.07 ± 0.13 µg/mL) in comparison with the reference drug doxorubicin that has (IC50 = 2.79 ± 0.07 µg / mL). Then compound 5d subjected to further studies such as cell cycle analysis and apoptosis. Apoptosis was confirmed by the upregulation of Bax, downregulation of Bcl-2, and the increase of the caspase 3/7percentage. CONCLUSION: Insertion of pyrazole, oxadiazole and, quinazoline moieties with 2-thiohydantoin moiety led to the enhancement of its anti-proliferative activity. Hence they can be used as anticancer agents.

Design, Synthesis, Anti-Proliferative Evaluation and Cell Cycle Analysis of Hybrid 2-Quinolones.

BACKGROUND: Quinolones are a significant group of nitrogen heterocyclic compounds that exist in therapeutic agents, alkaloids, and synthetic small molecules that have important biological activities. A wide range of quinolones have been used as antituberculosis, antibacterial, anti-malarial, antifungal, anticonvulsant, anticancer agents and urease inhibitors. METHODS: Ethyl 3,3-disubstituted-2-cyano propionates containing hybride quinolones derivatives were synthesized by the reaction of 1-amino-7-hydroxy-4-methylquinolin-2(1H)-one and its dibromo derivative with α, ß-unsaturated carbonyl in ethanol. RESULTS: A novel series of hybrid 2-quinolone derivatives was designed and synthesized. The compounds structures were confirmed using different spectroscopic methods and elemental analysis. The cytotoxic activities of all the compounds were assessed against HepG2 cell line in comparison with doxorubicin as a standard drug. CONCLUSION: Most compounds revealed superior anti-proliferative activity than the standard. Compound 4b, is the most active compound (IC50 = 0.39mM) compared with doxorubicin (IC50 = 9.23mM). DNA flow cytometric analysis of compound 4b showed cell cycle arrest at G2/M phase with a concomitant increase of cells in apoptotic phase. Dual annexin-V/ propidium iodide staining assay of compound 4b revealed that the selected candidate increased the apoptosis of HepG-2 cells more than control.

Ammonium chloride catalyzed synthesis of novel Schiff bases from spiro[indoline-3,4'-pyran]-3'-carbonitriles and evaluation of their antimicrobial and anti-breast cancer activities.

BACKGROUND: Indolinone and spiro-indoline derivatives have been employed in the preparation of different important therapeutic compounds required for treatment of anticonvulsants, antibacterial, Antitubercular, and anticancer activities. Schiff bases have been found to possess various pharmacological activities such as antitubercular, plant growth inhibiting, insecticsidal, central nerve system depressant, antibacterial, anticancer, anti-inflammatory, and antimicrobial. Mannich bases have a variety of biological activities such as antibacterial and antifungal activities. RESULTS: In this study, a green, rapid and efficient protocol for the synthesis of a new series of Schiff bases from spiro[indoline-3,4'-pyran]-3'-carbonitrile derivatives using ammonium chloride as a very inexpensive and readily available reagent. The prepared compounds were assessed in vitro for their antimicrobial activity. Also, the cytotoxic activity of the prepared compounds was assessed in vitro against human cells line MCF7 breast cancer. CONCLUSION: Good activity was distinguished for Schiff bases from spiro[indoline-3,4'-pyran]-3'-carbonitriles, with some members recorded higher antimicrobial and anti-breast cancer activities.Graphical abstractNovel Schiff bases from spiro[indoline-3,4'-pyran]-3'-carbonitriles.

Modification of chitosan derivatives of environmental and biological interest: a green chemistry approach.

Chitosan is a non-toxic polyaminosaccharide that is available in a variety of useful forms, and its chemical and biological properties make it a very attractive biomaterial that could be used in a wide variety of medicinal applications. This work focuses on the preparation of different chitosan derivatives by treatment with ethyl cellulose, cellulose triacetate and different carbohydrates in both neutral and slightly acidic media. It also addresses modification with glycidyltrimethyl ammonium chloride, phthalic anhydride and succinic acid derivatives. The obtained derivatives were crosslinked with glutaraldehyde. Thermo-gravimetric (TGA) and FT-IR spectroscopic analyses and electron scanning microscopy (SEM) were used to characterize the obtained products and demonstrate the success of the chitosan-modification process. The obtained products were tested for their ability to uptake transition metal ions from aqueous solutions, and their ion-uptake efficiency was determined with the aid of the ICP-AES technique. The bioactivity of some selected products was tested to study the effect of their concentrations on selected microorganisms. Burkholderia cepaci, Aspergillus niger, and Candida albicans were selected as representative examples of bacteria, yeasts and fungi, respectively.