James T. P. Matshwele

This study reports the synthesis, characterization, and adsorption performance of magnetite (Fe3O ₄ ) functionalized with sodium 3‐sulfobenzoate (MSF) for the removal of PdCl ₂ from aqueous solutions, supported by experimental and computational approaches. The adsorbent was prepared by surface functionalization and characterized using TEM, SEM, EDS, XRD, and FTIR, confirming a spinel Fe ₃ O ₄ structure, sulfonate incorporation, and an average particle size of 18.3 nm. Batch adsorption experiments revealed that Pd removal efficiency increases with an increase in adsorbent dosage, reaching an optimum adsorption capacity of 1.8 mg·L ⁻¹ . The adsorption process is influenced by temperature, with the optimum adsorption capacity observed at 30°C. The adsorption capacity is dependent on initial Pd concentration, with equilibrium achieved at 15–20 μM. Thermodynamic modeling showed that the adsorption fitted both Langmuir ( R ² = 0.985) and Freundlich ( R ² = 0.983) isotherms, indicating monolayer adsorption on heterogeneous adsorption sites. The Langmuir constant ( K _l = 3.54 × 10 ⁵ L·mol ⁻¹ ) and monolayer capacity (1.29 × 10 ⁻⁶ mol·g ⁻¹ ) suggest strong site‐specific interactions, while the Dubinin–Radushkevich model yielded a mean adsorption energy of 11.13 kJ·mol ⁻¹ , confirming chemisorption. Kinetic studies demonstrated that the process follows a pseudo–second‐order model ( R ² = 0.99), indicating chemical interaction rather than physical adsorption. FTIR analysis of spent adsorbents showed reduced OH band intensity, suggesting Pd coordination at hydroxyl sites, while XRD confirmed structural integrity after adsorption. SEM and EDS mapping revealed heterogeneous Pd distribution on the surface. Density functional theory (DFT) simulations using CASTEP supported these findings, showing strong orbital hybridization between Pd 4d and O 2p orbitals, Pd–O bond lengths of 2.08 Å, and an adsorption energy of −7.89 kJ·mol ⁻¹ , indicative of exothermic ligand coordination. This confirms that PdCl ₂ adsorption on MSF occurs through chemisorption by complexation at sulfonate and hydroxyl sites.

The ongoing development of bacterial resistance to antibiotics is a global challenge. Research in that field is thus necessary. Analytical techniques are required for such a purpose. From this perspective, the focus was on atomic absorption spectrometry (AAS). Although it is old, AAS often offers unexpected potential. Of course, this should be exploited. The aim was therefore to demonstrate the versatility of the technique in antibacterial research. This is illustrated by various examples of its practical application. AAS can be used, for example, to confirm the identity of antibacterial compounds, for purity controls, or to quantify the antibiotics in pharmaceutical preparations. The latter allowed analysis without laborious sample preparation and without interference from other excipients. In addition, AAS can help elucidate the mode of action or resistance mechanisms. In this context, quantifying the accumulation of the antibiotic drug in the cell of (resistant) bacteria appears to play an important role. The general application of AAS is not limited to metal-containing drugs, but also enables the determination of some organic chemical antibiotics. Altogether, this perspective presents a range of applications for AAS in antibacterial research, intending to raise awareness of the method and may thus contribute to the fight against resistance.

A new polypyridyl ligand 4‐(4‐nitrophenoxy)‐N,N‐bis (pyridin‐2‐ylmethyl)aniline (L1) and its three ruthenium (II/III) complexes, [Ru (Cl)₃L1] (C1), [Ru(L1)₂]Cl (C2), and [RuCl (dpa)L1] (C3) where dpa = 2,2‐dipyridylamine, have been successfully synthesized and characterized using Fourier‐transform infrared spectroscopy (FTIR), elemental analysis, proton nuclear magnetic resonance (¹H NMR), high‐resolution electrospray ionization mass spectrometry (HR‐ESI‐MS), thermal analysis (thermogravimetric analysis [TGA] and differential scanning calorimetry [DSC]), UV/Vis absorption, and magnetic susceptibility. The structures of the ligand and the complexes were optimized, and the structural characteristics were determined by density functional theory (DFT) using the B3LYP‐GD3/6‐311G++(d,p) method. Optimized FTIR vibrational frequencies and ¹H NMR chemical shifts agreed well with the corresponding experimental FTIR and ¹H NMR data. In vitro cytotoxicity of the ligand and the complexes were evaluated against the MCF‐7 breast cancer cell line. Ligand L1 was the most potent with an IC₅₀ of 38.45 μM, followed by C2 with an IC₅₀ of 45.23 μM. However, the ligand and the complexes showed low antiproliferative activity compared to cisplatin, which had an IC₅₀ of 9.67 μM. To predict the reactivity trend of L1 and the complexes, frontier molecular orbital (FMO) analysis was performed. The FMO energy gap (Eg = E_LUMO − E_HOMO) for C2 was found to be 1.675 eV, which was the lowest among all the complexes or L1. In addition, molecular docking studies were carried out so as to predict the binding capacity of L1 and the complexes to estrogen receptor alpha (ER‐α). The results showed that C2 has the most negative binding energy score (−9.63 kcal/mol), which indicates more stable adducts with the key amino acid residues at the active sites of ER‐α. Furthermore, C2 displayed the lowest inhibition constant (K_i) of 0.09 μM compared to all the complexes or L1. These results are very promising and show that the novel complex C2 may help in the development of anticancer drugs.

The structure of pyridin-4-ylmethyl 4-aminobenzoate was determined using single crystal X-ray diffraction. The compound was also characterized by elemental analysis, which showed the product was pure, and Fourier-transform infrared spectroscopy, which showed all important functional groups associated with the molecule. The compound crystallized in the orthorhombic space group Pna2₁, and the unit cell parameters were: a = 11.1735(16) Å, b = 8.3548(13) Å, c = 12.3831(17) Å, V = 1156.0(3) ų, Z = 4. The crystal structure was solved by intrinsic phasing and refined to the final values R₁ = 0.0429 and wR₂ = 0.1312.

A series of ester and ether bridged compounds bearing the nitro and amino moieties were synthesized and characterized inorder to assess their ability to potentially serve as antibacterial agents against drug resistant bacteria. All the compounds were obtained at considerable yields while characterization techniques confirmed their succesful synthesis. Furthermore, their antimicrobial assesments showed that all the compounds exhibited antibacterial activity against the Gram-negative bacterial strains, both Klebsiella pneumoniae and its drug resistant counterpart. On the contrary they were poorly active against S. aureus and MRSA. According to the MIC data all the compounds showed activity of 0.22 to 0.24 mM towards MDR-K. pneumonieae. As for K. pneumoniae, the nitro derivatives L1 and L4 showed significantly higher MIC of 0.23 and 0.26 mM respectivelly while the amino derivatives L2 and L3 were more active, with MIC values of 0.16 mM. Finally, the time kill kinetics study showed that L2 and L3 were bacteriostatic while L1 and L4 were bactericidal towards K. pneumoniae. However, all the compounds were bactericidal towards MDR- K. pneumoniae.

Plants continue to provide unlimited pharmacologically active compounds that can treat various illnesses, including cancer. The Solanaceae family, besides providing economically important food plants, such as potatoes and tomatoes, has been exploited extensively in folk medicine, as it provides an array of bioactive compounds. Many studies have demonstrated the anticancer potency of some of the compounds, but the corresponding molecular targets are not well defined. However, advances in molecular cell biology and in silico modelling have made it possible to dissect some of the underlying mechanisms. By reviewing the literature over the last five years, we provide an update on anticancer mechanisms associated with phytochemicals isolated from species in the Solanaceae plant family. These mechanisms are conveniently grouped into cell cycle arrest, transcription regulation, modulation of autophagy, inhibition of signalling pathways, suppression of metabolic enzymes, and membrane disruption. The majority of the bioactive compounds exert their antiproliferative effects by inhibiting diverse signalling pathways, as well as arresting the cell cycle. Furthermore, some of the phytochemicals are effective against more than one cancer type. Therefore, understanding these mechanisms provides paths for future formulation of novel anticancer drugs, as well as highlighting potential areas of research.