New heteroaromatic polyazomethines containing naphthyridine moieties: Synthesis, characterization, and biological screening

Favorable Heteroaromatic Thiazole-Based Polyurea Derivatives as Interesting Biologically Active Products

This research sought to synthesize a new set of heteroaromatic thiazole-based polyurea derivatives with sulfur links in the polymers' main chains, which were denoted by the acronyms PU_1-5. Using pyridine as a solvent, a diphenylsulfide-based aminothiazole monomer (M2) was polymerized via solution polycondensation with varied aromatic, aliphatic, and cyclic diisocyanates. Typical characterization methods were used to confirm the structures of the premonomer, monomer, and fully generated polymers. The XRD results revealed that aromatic-based polymers had higher crystallinity than aliphatic and cyclic derivatives. SEM was used to visualize the surfaces of PU₁, PU₄, and PU₅, revealing spongy and porous shapes, shapes resembling wooden planks and sticks, and shapes resembling coral reefs with floral shapes at various magnifications. The polymers demonstrated thermal stability. The numerical results for PDTmax are listed in the following order, ranked from lowest to highest: PU₁ < PU₂ < PU₃ < PU₅ < PU₄. The FDT values for the aliphatic-based derivatives (PU₄ and PU₅) were lower than those for the aromatic-based ones (616, 655, and 665 °C). PU₃ showed the greatest inhibitory impact against the bacteria and fungi under investigation. In addition, PU₄ and PU₅ demonstrated antifungal activities that, in contrast with the other products, were on the lower end of the spectrum. Furthermore, the intended polymers were also tested for the presence of the proteins 1KNZ, 1JIJ, and 1IYL, which are frequently utilized as model organisms for E. coli (Gram-negative bacteria), S. aureus (Gram-positive bacteria), and C. albicans (fungal pathogens). This study's findings are consistent with the outcomes of the subjective screening.

An overview of the synthetic strategies of C3-symmetric polymeric materials containing benzene and triazine cores and their biomedical applications

C3-symmetric star-shaped materials are an emerging category of porous organic polymers with distinctive properties such as permanent porosity, good thermal and chemical stability, high surface area, and appropriate functionalization that promote outstanding potential in various applications. This review is mostly about constructing benzene or s-triazine rings as the center of C3-symmetric molecules and using side-arm reactions to add functions to these molecules. Over and above this, the performance of various polymerization processes has been additionally investigated in detail, including the trimerization of alkynes or aromatic nitriles, polycondensation of monomers with specific functional groups, and cross-coupling building blocks with benzene or triazine cores. Finally, the most recent progress in biomedical applications for C3-symmetric materials based on benzene or s-triazine have been summarized.

Novel biologically active polyurea derivatives and its TiO2-doped nanocomposites

A new series of polyurea derivatives and its nanocomposites were synthesised by the solution polycondensation method through the interaction between 4(2-aminothiazol-4-ylbenzylidene)-4-(tert-butyl) cyclohexanone and diisocyanate compound in pyridine. The PU1-3 structure was confirmed using Fourier transform-infrared (FTIR) spectroscopy and characterised by solubility, viscometry, gel permeation chromatography (GPC), and X-ray diffraction (XRD) analysis. In addition, PU1-3 was evaluated by TGA. Polyurea-TiO2nanocomposites were synthesised using the same technique as that of PU1-3 by adding TiO2 as a nanofiller. The thermal properties of PU2TiO2a-d were evaluated by TGA. Moreover, the morphological properties of a selected sample were examined by SEM and TEM. In addition, PU1-3 and PU2TiO2a-d were examined for antimicrobial activity against certain bacteria and fungi. The PU1-3 showed antibacterial activity against some of the tested bacteria and fungi, as did PU2TiO2a-d, which increased with the increase in TiO2 content. Furthermore, molecular docking studies were displayed against all PU1-3 derivatives against two types of proteins. The results show that the increase in the strength of π-H interactions and H-donors contributed to improved binding of PU2 compared to PU1 andPU3. The docking of 1KZN against the tested polymers suggests an increase in the docking score of PU2, then PU1, and PU3, which is in agreement with the antibacterial study.

Highly selective heteroaromatic sulfur containing polyamides for Hg+2 environmental remediation

Environmental remediation concerns about pollution and contamination removal from environmental media, such as soil, air, or surface water. Enormous efforts have been applied in metal removal from surface water. In this study, four novel heteroaromatic sulfur-containing polyamides 6a-d carry both types of aliphatic and aromatic species in their polymer backbones as selective adsorbents for Hg+2 metal ion from aqueous solution have been synthesized in considerable amounts. The polycondensation method at low temperature is used as a simple and low coast polymerization technique. This occurred by the interaction of the thiophene-based monomer 5 with different diacid chlorides of both types. Beforehand the polymerization, the structures of monomer 5 were confirmed by spectral and elemental analyses. Also, the structures of the new polymers were investigated by both spectral and elemental analysis; besides their solubility, GPC data, XRD diffraction patterns, thermal analysis, and FE-SEM micrographs. The synthesized polymers were freely soluble in polar protic solvents due to the presence of heteroaromatic sulfur functional groups. Furthermore, the analytical competition of the new polymers has been tested using inductively coupled plasma-optical emission spectrometry (ICP-OES) for its selective extraction across different metal ions. Polymer 6c was the most selective toward Hg+2 and considered as a highly selective adsorbent for Hg+2 environmental remediation among all derivatives and its adsorption detection and efficiency were also investigated. Polymer 6c showed the most effective adsorption quantity on its surface at pH = 1. Moreover, the calculated adsorption isotherm showed a typical isotherm to the Langmuir adsorption type. This showed that the adsorption capacity of polymer 6c for Hg+2 was 47.95 mg g-1. These novel polymers are serving as simple and inexpensive heavy metal ions adsorbent materials from drinking water and wastewater.

Sulfone-modified chitosan as selective adsorbent for the extraction of toxic Hg(II) metal ions

In this study, a new category of sulfone-modified chitosan derivatives as surface-selective adsorbents for the extraction of toxic Hg(II) metal has been synthesized in good yield. Sulfone-modified chitosan/5–20 based on variable loading of the corresponding phenacyl bromide (5, 10, 15, and 20% with respect to the original weight of the pure chitosan) was synthesized. The β-ketosulfone derivative, namely 1–(4-bromophenyl)-2-(phenylsulfonyl)ethanone, was first prepared by treatment of the corresponding phenacyl bromide with a sufficient amount of sodium benzene sulfinate; its chemical structure was confirmed by spectral analyses, including Fourier transform infrared spectroscopy, 1H-NMR, 13C-NMR, and mass spectrometry. Then, sulfone-modified chitosan/5–20 derivatives were synthesized by the interaction of chitosan with a freshly prepared p-bromo-β-ketosulfone derivative in a mildly acidic aqueous solution using the solution-blending technique. Sulfone-modified chitosan/5–20 derivatives were identified and characterized using common characterization techniques, including Fourier transform infrared spectroscopy, field-emission scanning electron microscope, powder X-ray diffraction, and thermal behaviour. A strong interaction was displayed between chitosan and its corresponding β-ketosulfones in powder X-ray diffraction, which was confirmed by significant 2θ shifts. Sulfone-modified chitosan/5–20 derivatives were detected as catalysts, which efficiently increased the thermal decomposition of pure chitosan. More particularly, the efficiency of sulfone-modified chitosan/5–20 derivatives for Hg(II), Pb(II), Ni(II), Al(III), Sr(II), Cr(III), Fe(III), Zn(II), and Mn(II) detection and adsorption was also investigated using inductively coupled plasma optical emission spectrometry. The sulfone-modified chitosan/5 derivative exhibited the highest adsorption efficiency. The most effective quantitative adsorption onto the sulfone-modified chitosan/5 surface was detected at pH = 2. In addition to that, the adsorption isotherm showed that the adsorption capacity of sulfone-modified chitosan/5 for Hg(II) was 122.47 mg g−1 and that its adsorption isotherm was in agreement with the Langmuir adsorption isotherm.

Thermally stable hybrid polyarylidene(azomethine-ether)s polymers (PAAP): an ultrasensitive arsenic(III) sensor approach

A new category of thermally stable hybrid polyarylidene(azomethine-ether)s and copolyarylidene(azomethine-ether)s (PAAP) based on diarylidenecycloalkanones has been synthesized using solution polycondensation method. For potential cationic sensor development, a thin layer of PAAP onto a flat glassy carbon electrode (GCE, surface area: 0.0316 cm²) was prepared with conducting nafion (5%) coating agent to fabricate a sensitive and selective arsenic (III) [As³⁺] ion in short response time in neutral buffer system. The fabricated cationic sensor was measured the analytical performances such as higher sensitivity, linear dynamic range, detection limit, reproducibility, and long-term stability towards As³⁺ ions. The sensitivity and detection limit were calculated as 2.714 μAμM^-1cm^-2 and 6.8 ± 0.1 nM (SNR of 3; 3N/S) respectively from the calibration curve. This novel approach can be initiated a well-organized route of an efficient development of heavy selective arsenic sensor for hazardous pollutants in biological, environmental, and health care fields. Real sample analysis for various environmental sample was performed with PAAP-modified-GCE.

The impact of graphene nano-plates on the behavior of novel conducting polyazomethine nanocomposites

Highly conducting polyazomethine/graphene nano-plate nanocomposites were easily fabricated, and their electrical conductivity values reach those of semiconductors.