A simple and highly efficient protocol was developed for one-pot synthesis of polyfunctionalized spirothiazolidin-4-ones using sulfonated mesoporous silica (MCM-SO₃H) as a heterogenous and reusable acidic catalyst. In comparison to the reported synthetic methods for the synthesis of thiazolidin-4-one and spirothiazolidin-4-one derivatives, this strategy provides superior yields under mild conditions, while avoiding hazardous solvents.

The regio- and stereochemical polar [3 + 2] cycloaddition of azomethine ylides, which were generated in situ by the reaction of isatin and sarcosine or benzylamine, with (E)-3-aryl-1-(pyren-1-yl)prop-2-en-1-ones as dipolarophiles, was studied using experimental and theoretical methods. The chemical structures and relative configurations of all products have been fully established by 1D and 2D homonuclear and heteronuclear correlation NMR spectrometry. The effects of the electronic and steric factors of the reactions were discussed. The photophysical properties of the synthesized spiro[indoline-3,2′-pyrrolidin]-2-ones and 5′-phenyl-spiro[indoline-3,2′-pyrrolidin]-2-ones were studied. The mechanism of the reactions was investigated using global and local reactivity indices and frontier molecular orbital (FMO) analysis at the B3LYP/6-31G level of theory. The relationship between the electrophilicity index ω of the dipolarophiles and the Hammett constant σ_p has been studied. The theoretical scale of reactivity correctly explains the electrophilic activation/deactivation effects promoted by electron-withdrawing and electron-releasing substituents in the para-position of the dipolarophiles.

A simple, convenient, and regioselective 1,3-dipolar cycloaddition of 9-diazo-9H-fluorene or diphenyldiazomethane to 2-arylidene-1H-indene-1,3(2H)-diones afforded a series of novel dispiro[indane-2,3′-pyrazole-5′,9″-fluorene] and spiro[indene-2,3′-pyrazole] derivatives in moderate to excellent yields. Chemical structures of all products have been fully established by 1D (¹H, ¹³C, ¹³C-DEPT 90) and 2D homonuclear and heteronuclear correlation NMR spectrometry experiments (¹H-¹H-DQF-COSY, ¹H-¹H-TOCSY, ¹³C-¹H-HSQC, ¹³C-¹H-HMBC, ¹H-¹H ROESY, and HSQC-TOCSY) and regioselectivity of the reported procedure has been demonstrated in all products. DFT reactivity indices of these cycloaddition reactions have been studied. 1,3-Dipolar cycloaddition of 9-diazo-9H-fluorene and diphenyldiazomethane to 2-arylidene-1H-indene-1,3(2H)-diones as dipolarophiles are reactions governed by a concerted mechanism exhibiting high regioselectivity.

Limestone mining waste and its derived CaO were checked as an adsorbents of pb²⁺, Cu²⁺, and Cd²⁺ ions from water solution. The characterization of Limestone and calcined limestone was studied by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), Scanning Electron Microscope (SEM), and Surface area measurements (BET). The optimum conditions of sorbent dosage, pH, initial concentration, and contact time factors were investigated for pristine limestone and calcined limestone absorbents. The results indicate that the optimum initial concentrations of (C_i) were 1200, 500, and 300 ppm for Pb, Cu, and Cd, respectively, using calcined limestone adsorbent, while using the pristine limestone adsorbent, the corresponding optimum initial concentrations were 700, 110, and 50 ppm. In the ternary system sorption, the results indicated that the selectivity …

A novel compound, 2,6-bis-[1-(2-phenylhydrazono)ethyl]pyridine (BPEP), was synthesized and confirmed by NMR and IR spectroscopy. BPEP was examined as an inhibitor for the corrosion of zinc electrode in 1.0 M HCl. The inhibition efficiency of BPEP was assessed through various techniques such as hydrogen evolution, galvanostatic polarization, potentiodynamic anodic polarization, and electrochemical impedance spectroscopy. The inhibiting action of BPEP was explained in terms of the formation of a stable complex between zinc ions and BPEP and then adsorbed onto the zinc surface. The formation of the complex was established by FT-IR spectroscopy. A conductometric titration indicated that the stoichiometry of Zn⁺²:BPEP (metal:ligand) is 1:1. The adsorption follows the Langmuir isotherm. The Galvanostatic polarization measurements have shown that the BPEP molecule acts as a mixed-type inhibitor. The pitting potential shifted in the noble direction, indicating that the inhibition of pitting corrosion of zinc in the presence of BPEP.The activation energy and themodyanamic parameters of the adsorption process were calculated and have been explained.

Six new highly fluorescent 5-(aryl)-1-phenyl-3-(pyren-1yl)-2-pyrazolines were synthesized by reaction of various (E)-3-aryl-1-(pyren-1-yl)prop-2-en-1-ones with phenyl hydrazine in the presence of sulfonated mesoporous silica (MCM-SO₃H) as efficient and eco-friendly acidic catalyst. The chemical structures of all synthesized compounds were illustrated on the basis of spectral data (IR, ¹H NMR and ¹³C NMR). This was followed by photophysical properties-based absorption and emission studies of the target compounds in solutions of different solvent polarities. The microenvironment-sensitive fluorescent pyrazolines labeled with pyrene exhibited valuable fluorescence properties with emission in the range of 600–700 nm with a marked response to change in the environmental polarities. A significant and pronounced red shift was observed in the emission spectrum of 5-(aryl)-1-phenyl-3-(pyren-1yl)-2-pyrazolines Δλ ∼ 50 nm compared to the absorption spectrum Δλ ∼ 10 nm upon increasing the solvent polarity. This indicated the presence of higher dipole moment in the excited state than in the ground state and the transition involved are π-π* transition through the charge transfer phenomena. The fundamental understanding of solvatochromic properties were analyzed through Lippert-Mataga and Reichardts correlations in order to estimate the change in dipole moments (Δμ) which suggested the emissive state of designed fluorescent 2-pyrazoline derivatives is of strong ICT character.

In this study, a new series of 2,7-dichloro-4-(2-substituted-amino acetyl)fluorene derivatives were synthesized, characterized and evaluated for their antimicrobial activity and screened for cytotoxic activity against human lung carcinoma (A-549) and human breast carcinoma (MCF-7) cell lines. Most of the synthesized compounds displayed significant activity against A-549 and MCF-7 cell lines when compared to 5-fluorouracil (5-FU), which was used as a reference drug. In addition, some of these reported novel compounds exhibited promising antibacterial and antifungal properties. A molecular docking study was performed to identify the mechanism of action of the synthesized compounds, which suggested binding interactions with the active sites of dihydrofolate reductase (DHFR).

Background

Sulfonamide derivatives are of great attention due to their wide spectrum of biological activities. Sulfonamides conjugated with acetamide fragments exhibit antimicrobial and anticancer activities. The inhibition dihydrofolate reductase (DHFR) is considered as one of the most prominent mechanism though which sulfonamide derivatives exhibits antimicrobial and antitumor activities.

Results

In this study, a new series of 2-(arylamino)acetamides and N-arylacetamides containing sulfonamide moieties were designed, synthesized, characterized and assessed for their antimicrobial activity and screened for cytotoxic activity against human lung carcinoma (A-549) and human breast carcinoma (MCF-7) cell lines. A molecular docking study was performed to identify the mode of action of the synthesized compounds and their good binding interactions were observed with the active sites of dihydrofolate reductase (DHFR).

Conclusion

Most of the synthesized compounds showed significant activity against A-549 and MCF-7 when compared to 5-Fluorouracil (5-FU), which was used as a reference drug. Some of these synthesized compounds are active as antibacterial and antifungal agents.

A simplistic and highly effective protocol for the synthesis of a new class of poly-functionalized innovative nicotinonitriles incorporating pyrene and/or fluorene moieties has been developed through the domino four-component condensation reaction of 1-(pyren-1-yl)ethanone/1-(9H-fluoren-2-yl)ethanone, numerous aromatic aldehydes, and 3-oxo-3-(pyren-1-yl)propanenitrile/3-(9H-fluoren-2-yl)-3-oxopropanenitrile and ammonium acetate in acetic acid as a reaction medium. The advantages of this approach are the short reaction time, excellent yield, and the easy experimental workup that affords substrate diversity and operative competence under metal-free reaction conditions for the formation of C–C and C–N bonds. The substituent effects on the photophysical property-based absorption and the emission of the synthesized compounds in dichloromethane have been well-investigated. Strong absorption quenching of around 100 nm was observed when substitution of the benzene ring at the C₄-position of the pyridine moiety occurred with an electron-donating (–N(CH₃)₂) group. All of the newly synthesized nicotinonitrile derivatives showed strong blue-green fluorescence emission with maxima in the range between 420–630 nm. These highly pronounced emission spectra will help this family of compounds to find application in many areas and the field of materials science.

Steel and its alloys are essential materials in various industries, but they quickly react with the surrounding environment, especially humid ones, which leads to their destruction and corrosion on a large scale. Replacing synthetic organic inhibitors with plant-extracted or natural molecules has recently been a major challenge in terms of environmental and industrial aspects. In this report, the inhibitory dominance, adsorption of myrrh extract (MRE) as a green corrosion inhibitor on 330 stainless steel (SS) in 1.0 M HCl solution at the temperature range of 25 to 55 °C were explored. Weight loss (WL) measurements showed apparent inhibition efficiency (% IE) of MRE of up to 93.6% at 55 °C. The % IE values increased sharply with increasing inhibitor concentration and medium temperature. Adsorption investigations confirmed that the extract molecules were strongly adsorbed on the SS surface and were consistent with the Langmuir and Frumkin models. Polarization monitoring showed that the MRE behaves as a mixed-type inhibitor. EIS was also used to quantitatively evaluate the efficiency of the passive layer on the SS surface. All thermodynamic (DH, DS, DG) and kinetic (Kads, Ea) parameters were calculated and analyzed. XPS was used to inspect the surface chemistry of SS and the nature of MRE-SS bonds. AFM demonstrated that the SS sample in the blank solution appears to be severely damaged and has the highest roughness of about 382.6 nm, compared to that obtained in the presence of MRE (145.61 nm). Various theoretical and computational methods were used to predict the performance of the examined inhibitor. All experimental findings of the different techniques are in excellent agreement with each other and with theoretical speculations. The outcomes of this study are thought to have some bearing on the sensible development of a potent inhibitor against the corrosion of metals in acidic environments.